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Sample records for tall obstacles nearby

  1. Tall Corn Ethanol LLC | Open Energy Information

    Open Energy Info (EERE)

    Tall Corn Ethanol LLC Jump to: navigation, search Name: Tall Corn Ethanol LLC Place: Coon Rapids, Iowa Zip: 50058 Product: Farmer owned bioethanol production company which owns a...

  2. Scientific American: "Tall Trees Sucked Dry by Global Warming...

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

    Scientific American: "Tall Trees Sucked Dry by Global Warming" Scientific American: "Tall Trees Sucked Dry by Global Warming" Climate change will challenge tall trees like ...

  3. Scientific American: "Tall Trees Sucked Dry by Global Warming...

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

    Scientific American: "Tall Trees Sucked Dry by Global Warming" June 7, 2015 Scientific American: "Tall Trees Sucked Dry by Global Warming" A well-known scientific principle ...

  4. Apparatus for obstacle traversion

    DOE Patents [OSTI]

    Borenstein, Johann


    An apparatus for traversing obstacles having an elongated, round, flexible body that includes a plurality of drive track assemblies. The plurality of drive track assemblies cooperate to provide forward propulsion wherever a propulsion member is in contact with any feature of the environment, regardless of how many or which ones of the plurality of drive track assemblies make contact with such environmental feature.


    Office of Scientific and Technical Information (OSTI)


  6. Scientific American: "Tall Trees Sucked Dry by Global Warming"

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

    Scientific American: "Tall Trees Sucked Dry by Global Warming" Scientific American: "Tall Trees Sucked Dry by Global Warming" Climate change will challenge tall trees like California's redwoods. June 7, 2015 Scientific American: "Tall Trees Sucked Dry by Global Warming" Climate change will challenge tall trees like California's redwoods Scientific American: "Tall Trees Sucked Dry by Global Warming" A well-known scientific principle describing how water

  7. Obstacle-avoiding navigation system

    DOE Patents [OSTI]

    Borenstein, Johann; Koren, Yoram; Levine, Simon P.


    A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

  8. Chemical composition of biomass from tall perennial tropical grasses

    SciTech Connect (OSTI)

    Prine, G.M.; Stricker, J.A.; Anderson, D.L.


    The tall perennial tropical grasses, elephantgrass (Pennisetum purpureum Schum.), sugarcane and energycane (Saccharum sp.) and erianthus (Erianthus arundenaceum (Retz) Jesw.) have given very high oven dry biomass yields in Florida and the warm Lower South USA. No good complete analyses of the chemical composition of these grasses for planning potential energy use was available. We sampled treatments of several tall grass demonstrations and experiments containing high-biomass yielding genotypes of the above tall grass crops at several locations in Florida over the two growing seasons, 1992 and 1993. These samples were analyzed for crude protein, NDF, ADF, cellulose, hemicellulose, lignin, and IVDMD or IVOMD. The analysis for the above constituents are reported, along with biomass yields where available, for the tall grass accessions in the various demonstrations and experiments. Particular attention is given to values obtained from the high-yielding tall grasses grown on phosphatic clays in Polk County, FL, the area targeted by a NREL grant to help commercialize bioenergy use from these crops.

  9. Process for tertiary oil recovery using tall oil pitch

    DOE Patents [OSTI]

    Radke, C.J.


    A process and compositions for enhancing the recovery of acid crudes are disclosed. The process involves injecting caustic solutions into the reservoir to maintain a pH of 11 to 13. The fluid contains an effective amount of multivalent cation for inhibiting alkaline silica dissolution with the reservoir. A tall oil pitch soap is added as a polymeric mobility control agent. (DMC)

  10. Process for tertiary oil recovery using tall oil pitch

    DOE Patents [OSTI]

    Radke, Clayton J.


    Compositions and process employing same for enhancing the recovery of residual acid crudes, particularly heavy crudes, by injecting a composition comprising caustic in an amount sufficient to maintain a pH of at least about 11, preferably at least about 13, and a small but effective amount of a multivalent cation for inhibiting alkaline silica dissolution with the reservoir. Preferably a tall oil pitch soap is included and particularly for the heavy crudes a polymeric mobility control agent.

  11. Prolongation technologies for campaign life of tall oven

    SciTech Connect (OSTI)

    Doko, Yoshiji; Saji, Takafumi; Kitayama, Yoshiteru; Yoshida, Shuhei


    In Kashima Steel Works, 25-year-old 7-meter-high coke ovens have damage on their walls. However, by using new methods of internal in-situ investigation, ceramic welding for the extended central and upper portions of coke ovens has prolonged the campaign life for over 40 years without large-scale hot repair. In this paper, introduction of these new methods, its application in Kashima and the policy of repairing the tall coke oven are reported.

  12. Whole arm obstacle avoidance for teleoperated robots

    SciTech Connect (OSTI)

    Feddema, J.T.; Novak, J.L.


    This paper describes a collision avoidance system using Whole Arm Proximity (WHAP) sensors on a PUMA 560 robot arm. The capacitance-based sensors generate electric fields which can completely encompass the robot arm and detect obstacles as they approach from any direction. The directional obstacle information gathered by the WHAP sensors together with the sensor geometry and robot configuration is used to scale the commanded joint velocities of the robot. A linearized relationship between the WHAP sensor reading and the distance from the obstacle allows direct transformation of perturbations in VHAP readings to perturbations in joint velocities. The VHAP reading is used to directly reduce the component of the command input velocity along the normal axis of the sensor, allowing graceful reductions in speed as the arm approaches the obstacle. By scaling only the component of the velocity vector in the,direction of the nearest obstacles, the control system restricts motion in the direction of obstacles while permitting unconstrained motion in other directions.

  13. Statistics of dislocation pinning at localized obstacles

    SciTech Connect (OSTI)

    Dutta, A.; Bhattacharya, M. Barat, P.


    Pinning of dislocations at nanosized obstacles like precipitates, voids, and bubbles is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often studied at fundamental level by means of analytical tools, atomistic simulations, and finite element methods. Nevertheless, the information extracted from such studies cannot be utilized to its maximum extent on account of insufficient information about the underlying statistics of this process comprising a large number of dislocations and obstacles in a system. Here, we propose a new statistical approach, where the statistics of pinning of dislocations by idealized spherical obstacles is explored by taking into account the generalized size-distribution of the obstacles along with the dislocation density within a three-dimensional framework. Starting with a minimal set of material parameters, the framework employs the method of geometrical statistics with a few simple assumptions compatible with the real physical scenario. The application of this approach, in combination with the knowledge of fundamental dislocation-obstacle interactions, has successfully been demonstrated for dislocation pinning at nanovoids in neutron irradiated type 316-stainless steel in regard to the non-conservative motion of dislocations. An interesting phenomenon of transition from rare pinning to multiple pinning regimes with increasing irradiation temperature is revealed.

  14. Negative Resists for Ultra-Tall, High Aspect Ratio Microstructures

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

    Resists for Ultra-Tall, High Aspect Ratio Microstructures S. Lemke a , P. Goettert a , I. Rudolph a , J. Goettert b,* , B. Löchel a a Helmholtz-Zentrum Berlin (HZB) für Materialien und Energie GmbH, Institute for Nanometre Optics and Technology, Albert-Einstein-Str. 15, 12489 Berlin, Germany b Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806, USA *E-Mail: Abstract In this joint research project,

  15. Reconstructing householder vectors from Tall-Skinny QR

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

    Ballard, Grey Malone; Demmel, James; Grigori, Laura; Jacquelin, Mathias; Knight, Nicholas; Nguyen, Hong Diep


    The Tall-Skinny QR (TSQR) algorithm is more communication efficient than the standard Householder algorithm for QR decomposition of matrices with many more rows than columns. However, TSQR produces a different representation of the orthogonal factor and therefore requires more software development to support the new representation. Further, implicitly applying the orthogonal factor to the trailing matrix in the context of factoring a square matrix is more complicated and costly than with the Householder representation. We show how to perform TSQR and then reconstruct the Householder vector representation with the same asymptotic communication efficiency and little extra computational cost. We demonstratemore » the high performance and numerical stability of this algorithm both theoretically and empirically. The new Householder reconstruction algorithm allows us to design more efficient parallel QR algorithms, with significantly lower latency cost compared to Householder QR and lower bandwidth and latency costs compared with Communication-Avoiding QR (CAQR) algorithm. Experiments on supercomputers demonstrate the benefits of the communication cost improvements: in particular, our experiments show substantial improvements over tuned library implementations for tall-and-skinny matrices. Furthermore, we also provide algorithmic improvements to the Householder QR and CAQR algorithms, and we investigate several alternatives to the Householder reconstruction algorithm that sacrifice guarantees on numerical stability in some cases in order to obtain higher performance.« less

  16. Reconstructing householder vectors from Tall-Skinny QR

    SciTech Connect (OSTI)

    Ballard, Grey Malone; Demmel, James; Grigori, Laura; Jacquelin, Mathias; Knight, Nicholas; Nguyen, Hong Diep


    The Tall-Skinny QR (TSQR) algorithm is more communication efficient than the standard Householder algorithm for QR decomposition of matrices with many more rows than columns. However, TSQR produces a different representation of the orthogonal factor and therefore requires more software development to support the new representation. Further, implicitly applying the orthogonal factor to the trailing matrix in the context of factoring a square matrix is more complicated and costly than with the Householder representation. We show how to perform TSQR and then reconstruct the Householder vector representation with the same asymptotic communication efficiency and little extra computational cost. We demonstrate the high performance and numerical stability of this algorithm both theoretically and empirically. The new Householder reconstruction algorithm allows us to design more efficient parallel QR algorithms, with significantly lower latency cost compared to Householder QR and lower bandwidth and latency costs compared with Communication-Avoiding QR (CAQR) algorithm. Experiments on supercomputers demonstrate the benefits of the communication cost improvements: in particular, our experiments show substantial improvements over tuned library implementations for tall-and-skinny matrices. Furthermore, we also provide algorithmic improvements to the Householder QR and CAQR algorithms, and we investigate several alternatives to the Householder reconstruction algorithm that sacrifice guarantees on numerical stability in some cases in order to obtain higher performance.

  17. Tall Tower Wind Energy Monitoring and Numerical Model Validation in Northern Nevada

    SciTech Connect (OSTI)

    Koracin, D.; Kaplan, M.; Smith, C.; McCurdy, G.; Wolf, A.; McCord, T.; King, K.; Belu, R.; Horvath, K.


    The main objectives of this project were to conduct a tall-tower and sodar field campaign in complex terrain, investigate wind properties relevant to wind energy assessment, and evaluate high-resolution models with fixed and adaptive grid structures. Two 60-m towers at Virginia Peak ridges near Washoe Valley, Nevada, were instrumented with cup and vane anemometers as well as sonic anemometers, and an acoustic sounder (hereafter sodar) was installed near one of the towers. The towers were located 2,700 m apart with a vertical distance of 140 m elevation between their bases. Each tower had a downhill exposure of rolling complex terrain, with the nearby valley floor 3,200 m to the west and 800 m below the summit. Cup anemometers were installed at both towers at 20, 40, and 60 m, wind vanes at 20 and 60 m, and sonic anemometers at 20 and 60 m. The sodar measurements were nominally provided every 10 m in vertical distance from 40 to 200 m with the quality of the data generally decreasing with height. Surface air temperature, atmospheric pressure, and radiation measurements were conducted at 1.5 m AGL at both of the towers. Although the plan was to conduct a 1-year period of data collection, we extended the period (October 5, 2012 through February 24, 2014) to cover for possible data loss from instrument or communication problems. We also present a preliminary analysis of the towers and sodar data, including a detailed inventory of available and missing data as well as outliers. The analysis additionally includes calculation of the Weibull parameters, turbulence intensity, and initial computation of wind power density at various heights.


    SciTech Connect (OSTI)

    Rodriguez, David R.; Faherty, Jacqueline K.; Zuckerman, B.; Kastner, Joel H.; Bessell, M. S.; Murphy, Simon J.


    We describe a method that exploits data from the Galaxy Evolution Explorer (GALEX) ultraviolet and Wide-field Infrared Survey Explorer and Two Micron All Sky Survey infrared source catalogs, combined with proper motions and empirical pre-main sequence isochrones, to identify candidate nearby, young, low-mass stars. Applying our method across the full GALEX-covered sky, we identify 2031 mostly M-type stars that, for an assumed age of 10 (100) Myr, all lie within {approx}150 ({approx}90) pc of Earth. The distribution of M spectral subclasses among these {approx}2000 candidate young stars peaks sharply in the range M3-M4; these subtypes constitute 50% of the sample, consistent with studies of the M star population in the immediate solar neighborhood. We focus on a subset of 58 of these candidate young M stars in the vicinity of the Tucana-Horologium association. Only 20 of these 58 candidates were detected in the ROSAT All-Sky X-ray Survey-reflecting the greater sensitivity of GALEX for the purposes of identifying active nearby, young stars, particularly for stars of type M4 and later. Based on statistical analysis of the kinematics and/or spectroscopic followup of these 58 M stars, we find that 50% (29 stars) indeed have properties consistent with Tuc-Hor membership, while 12 are potential new members of the Columba association, and 2 may be AB Dor moving group members. Hence, {approx}75% of our initial subsample of 58 candidates are likely members of young (age {approx} 10-40 Myr) stellar moving groups within 100 pc, verifying that the stellar color- and kinematics-based selection algorithms described here can be used to efficiently isolate nearby, young, low-mass objects from among the field star population. Future studies will focus on characterizing additional subsamples selected from among this list of candidate nearby, young M stars.

  19. Orbital masses of nearby luminous galaxies

    SciTech Connect (OSTI)

    Karachentsev, Igor D.; Kudrya, Yuri N. E-mail:


    We use observational properties of galaxies accumulated in the Updated Nearby Galaxy Catalog to derive a dark matter mass of luminous galaxies via motions of their companions. The data on orbital-to-stellar mass ratio are presented for 15 luminous galaxies situated within 11 Mpc from us: the Milky Way, M31, M81, NGC 5128, IC342, NGC 253, NGC 4736, NGC 5236, NGC 6946, M101, NGC 4258, NGC 4594, NGC 3115, NGC 3627, and NGC 3368, as well as for a composite suite around other nearby galaxies of moderate and low luminosity. The typical ratio for these galaxies is M {sub orb}/M {sub *} = 31, corresponding to the mean local density of matter ? {sub m} = 0.09, i.e., one-third of the global cosmic density. This quantity seems to be rather an upper limit of dark matter density, since the peripheric population of the suites may suffer from the presence of fictitious unbound members. We note that the Milky Way and M31 halos have lower dimensions and lower stellar masses than those of the other 13 nearby luminous galaxies. However, the dark-to-stellar mass ratio for both the Milky Way and M31 is typical for other neighboring luminous galaxies. The distortion in the Hubble flow, observed around the Local Group and five other neighboring groups, yields their total masses within the radius of a zero velocity surface, R {sub 0}; these masses are slightly lower than the orbital and virial values. This difference may be due to the effect of dark energy producing a kind of 'mass defect' within R {sub 0}.

  20. Forty-Six-Foot Tall Needle Sculpture Rises Over Arts Quad > EMC2...

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

    Section EMC2 News Archived News Stories Forty-Six-Foot Tall Needle Sculpture Rises Over Arts Quad September 14th, 2014 By ANUSHKA MEHROTRA Students walking around campus this...

  1. Obstacle penetrating dynamic radar imaging system

    DOE Patents [OSTI]

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.


    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  2. Leucaena and tall grasses as energy crops in humid lower south USA

    SciTech Connect (OSTI)

    Prine, G.M.; Woodard, K.R.; Cunilio, T.V.


    The tropical leguminous shrub/tree, leucaena (Leucaena spp. mainly leucocephala), and perennial tropical tall grasses such as elephantgrass (Pennisetum purpureum), sugarcane, and energycane (Saccharum spp.) are well adapted to the long growing seasons and high rainfall of the humid lower South. In much of the area the topgrowth is killed by frost during winter and plants regenerate from underground parts in spring. Selected accessions from a duplicated 373 accession leucaena nursery had an average annual woody stem dry matter production of 31.4 Mg ha{sup -1}. Average oven dry stem wood yields from selected accessions adjusted for environmental enrichment over the 4 growth seasons were 78.9 Mg ha{sup -1} total and average annual yield of 19.7 Mg ha{sup -1}. The tall perennial grasses have linear growth rates of 18 to 27 g m{sup 2}d{sup -1} for long periods (140 to 196 d and sometimes longer) each season. Oven dry biomass yields of tall grasses have varied from 20 to 45 Mg ha{sup -1} in mild temperature locations to over 60 Mg ha{sup -1} yr{sup -1} in warm subtropics of the lower Florida peninsula. Tall grasses and leucaena, once established, may persist for many seasons. A map showing the possible range of the crops in lower South is shown. Highest biomass yields of tall grasses have been produced when irrigated with sewage effluent or when grown on phosphatic clay and muck soils of south Florida. Several companies are considering using leucaena and/or tall grasses for bioenergy in the phosphatic mining area of Polk County, Florida.

  3. Object Classification at the Nearby Supernova Factory (Journal...

    Office of Scientific and Technical Information (OSTI)

    Nearby Supernova Factory Citation Details In-Document ... Report Number(s): LBNL-696E TRN: US200815%%72 DOE Contract Number: DE-AC02-05CH11231 Resource Type: Journal Article ...

  4. Simulation of lightning attachment to open ground, tall towers and aircraft

    SciTech Connect (OSTI)

    Ratnamahilan, P.; Hoole, P. . Dept. of Electrical and Telecommunications Engineering); Ratnajeevan, S.; Hoole, H. . Dept. of Engineering)


    The characteristics of lightning waveforms are important in taking protective measures against it. However, many of these characteristics cannot be measured. This paper employs a mathematical model of lightning currents to write a software package to simulate all manner of lightning flashes. The capabilities available to us through this are demonstrated by extracting the behavior of lightning waveforms following attachment to open ground, tall towers and aircraft.

  5. On a Highly Nonlinear Self-Obstacle Optimal Control Problem

    SciTech Connect (OSTI)

    Di Donato, Daniela; Mugnai, Dimitri


    We consider a non-quadratic optimal control problem associated to a nonlinear elliptic variational inequality, where the obstacle is the control itself. We show that, fixed a desired profile, there exists an optimal solution which is not far from it. Detailed characterizations of the optimal solution are given, also in terms of approximating problems.

  6. New Process Helps Overcome Obstacles to Produce Renewable Fuels and

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

    Chemicals - News Releases | NREL New Process Helps Overcome Obstacles to Produce Renewable Fuels and Chemicals Lignin Valorization Study Published in Proceedings of the National Academy of Sciences August 20, 2014 There's an old saying in the biofuels industry: "You can make anything from lignin except money." But now, a new study may pave the way to challenging that adage. The study from the Energy Department's National Renewable Energy Laboratory (NREL) demonstrates a concept

  7. Stellar and gaseous nuclear disks observed in nearby (U)LIRGs...

    Office of Scientific and Technical Information (OSTI)

    Stellar and gaseous nuclear disks observed in nearby (U)LIRGs Citation Details In-Document Search Title: Stellar and gaseous nuclear disks observed in nearby (U)LIRGs We present ...

  8. Elimination of a spiral wave pinned at an obstacle by a train of plane waves: Effect of diffusion between obstacles and surrounding media

    SciTech Connect (OSTI)

    Tanaka, Masanobu; Hörning, Marcel; Kitahata, Hiroyuki; Yoshikawa, Kenichi


    In excitable media such as cardiac tissue and Belousov-Zhabotinsky reaction medium, spiral waves tend to anchor (pin) to local heterogeneities. In general, such pinned waves are difficult to eliminate and may progress to spatio-temporal chaos. Heterogeneities can be classified as either the absence or presence of diffusive interaction with the surrounding medium. In this study, we investigated the difference in the unpinning of spiral waves from obstacles with and without diffusive interaction, and found a profound difference. The pacing period required for unpinning at fixed obstacle size is larger in case of diffusive obstacles. Further, we deduced a generic theoretical framework that can predict the minimal unpinning period. Our results explain the difference in pacing periods between for the obstacles with and without diffusive interaction, and the difference is interpreted in terms of the local decrease of spiral wave velocity close to the obstacle boundary caused in the case of diffusive interaction.

  9. Cumulative effects in Swedish EIA practice - difficulties and obstacles

    SciTech Connect (OSTI)

    Waernbaeck, Antoienette Hilding-Rydevik, Tuija


    The importance of considering cumulative effects (CE) in the context of environmental assessment is manifested in the EU regulations. The demands on the contents of Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) documents explicitly ask for CE to be described. In Swedish environmental assessment documents CE are rarely described or included. The aim of this paper is to look into the reasons behind this fact in the Swedish context. The paper describes and analyse how actors implementing the EIA and SEA legislation in Sweden perceive the current situation in relation to the legislative demands and the inclusion of cumulative effects. Through semi-structured interviews the following questions have been explored: Is the phenomenon of CE discussed and included in the EIA/SEA process? What do the actors include in and what is their knowledge of the term and concept of CE? Which difficulties and obstacles do these actors experience and what possibilities for inclusion of CE do they see in the EIA/SEA process? A large number of obstacles and hindrances emerged from the interviews conducted. It can be concluded from the analysis that the will to act does seem to exist. A lack of knowledge in respect of how to include cumulative effects and a lack of clear regulations concerning how this should be done seem to be perceived as the main obstacles. The knowledge of the term and the phenomenon is furthermore quite narrow and not all encompassing. They experience that there is a lack of procedures in place. They also seem to lack knowledge of methods in relation to how to actually work, in practice, with CE and how to include CE in the EIA/SEA process. It can be stated that the existence of this poor picture in relation to practice concerning CE in the context of impact assessment mirrors the existing and so far rather vague demands in respect of the inclusion and assessment of CE in Swedish EIA and SEA legislation, regulations, guidelines and

  10. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    QUEST Camera Short Term Maintenance: Final Technical Report Citation Details In-Document Search Title: High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term ...

  11. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report Baltay, Charles 79 ASTRONOMY AND ASTROPHYSICS Study of Type 1a Supernovae...


    SciTech Connect (OSTI)

    McCormick, Alexander; Veilleux, Sylvain; Rupke, David S. N. E-mail:


    Recent observations have shown the presence of dust and molecular material in galactic winds, but relatively little is known about the distribution of these outflow components. To shed some light on this issue, we have used IRAC images from the Spitzer Space Telescope archive to investigate polycyclic aromatic hydrocarbon (PAH) emission from a sample of 16 local galaxies with known winds. Our focus on nearby sources (median distance 8.6 Mpc) has revealed detailed PAH structure in the winds and allowed us to measure extraplanar PAH emission. We have identified extraplanar PAH features on scales of {approx}0.8-6.0 kpc. We find a nearly linear correlation between the amount of extraplanar PAH emission and the total infrared flux, a proxy for star formation activity in the disk. Our results also indicate a correlation between the height of extraplanar PAH emission and star formation rate surface density, which supports the idea of a surface density threshold on the energy or momentum injection rate for producing detectable extraplanar wind material.

  13. Interaction between Cassiopeia A and nearby molecular clouds

    SciTech Connect (OSTI)

    Kilpatrick, C. D.; Bieging, J. H.; Rieke, G. H.


    We present spectroscopy of the supernova remnant Cassiopeia A (Cas A) observed at infrared wavelengths from 10 to 40 ?m with the Spitzer Space Telescope and at millimeter wavelengths in {sup 12}CO and {sup 13}CO J =2-1 (230 and 220 GHz) with the Heinrich Hertz Submillimeter Telescope. The IR spectra demonstrate high-velocity features toward a molecular cloud coincident with a region of bright radio continuum emission along the northern shock front of Cas A. The millimeter observations indicate that CO emission is broadened by a factor of two in some clouds toward Cas A, particularly to the south and west. We believe that these features trace interactions between the Cas A shock front and nearby molecular clouds. In addition, some of the molecular clouds that exhibit broadening in CO lie 1'-2' away from the furthest extent of the supernova remnant shock front. We propose that this material may be accelerated by ejecta with velocity significantly larger than the observed free-expansion velocity of the Cas A shock front. These observations may trace cloud interactions with fast-moving outflows such as the bipolar outflow along the southwest to northeast axis of the Cas A supernova remnant, as well as fast-moving knots seen emerging in other directions.

  14. Supernova Discoveries from the Nearby Supernova Factory (SNfactory)

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

    SNfactory International Collaboration,

    The Nearby Supernova Factory is an experiment designed to collect data on more Type Ia supernovae than have ever been studied in a single project before, and in so doing, to answer some fundamental questions about the nature of the universe. Type Ia supernovae are extraordinarily bright, remarkably uniform objects which make excellent "standard candles" for measuring the expansion rate of the universe. However, such stellar explosions are very rare, occurring only a couple of times per millenium in a typical galaxy, and remaining bright enough to detect only for a few weeks. Previous studies of Type Ia supernovae led to the discovery of the mysterious "dark energy" that is causing the universe to expand at an accelerating rate. To reduce the statistical uncertainties in previous experimental data, extensive spectral and photometric monitoring of more Type Ia supernovae is required. The SNfactory collaboration has built an automated system consisting of specialized software and custom-built hardware that systematically searches the sky for new supernovae, screens potential candidates, then performs multiple spectral and photometric observations on each supernova. These observations are stored in a database to be made available to supernova researchers world-wide for further study and analysis [copied from]. Users must register and agree to the open access honor system. Finding charts are in FITS format and may not be accessible through normal browser settings.

  15. Recoiling supermassive black holes: a search in the nearby universe

    SciTech Connect (OSTI)

    Lena, D.; Robinson, A.; Axon, D. J.; Merritt, D.; Marconi, A.; Capetti, A.; Batcheldor, D.


    The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed Hubble Space Telescope archival images of 14 nearby core ellipticals, finding evidence for small (? 10 pc) displacements between the active galactic nucleus (AGN; the location of the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding objects that may be affected by large-scale isophotal asymmetries, we consider six galaxies to have detected displacements, including M87, where a displacement was previously reported by Batcheldor et al. In individual objects, these displacements can be attributed to residual gravitational recoil oscillations following a major or minor merger within the last few gigayears. For plausible merger rates, however, there is a high probability of larger displacements than those observed, if SBH coalescence took place in these galaxies. Remarkably, the AGN-photocenter displacements are approximately aligned with the radio source axis in four of the six galaxies with displacements, including three of the four having relatively powerful kiloparsec-scale jets. This suggests intrinsic asymmetries in radio jet power as a possible displacement mechanism, although approximate alignments are also expected for gravitational recoil. Orbital motion in SBH binaries and interactions with massive perturbers can produce the observed displacement amplitudes but do not offer a ready explanation for the alignments.


    SciTech Connect (OSTI)

    Ford, H. Alyson; Bregman, Joel N.


    Small amounts of star formation in elliptical galaxies are suggested by several results: surprisingly young ages from optical line indices, cooling X-ray gas, and mid-infrared dust emission. Such star formation has previously been difficult to directly detect, but using ultraviolet Hubble Space Telescope Wide Field Camera 3 imaging, we have identified individual young stars and star clusters in four nearby ellipticals. Ongoing star formation is detected in all galaxies, including three ellipticals that have previously exhibited potential signposts of star-forming conditions (NGC 4636, NGC 4697, and NGC 4374), as well as the typical ''red and dead'' NGC 3379. The current star formation in our closest targets, where we are most complete, is between 2.0 and 9.8 Multiplication-Sign 10{sup -5} M{sub Sun} yr{sup -1}. The star formation history was roughly constant from 0.5 to 1.5 Gyr (at (3-5) Multiplication-Sign 10{sup -4} M{sub Sun} yr{sup -1}), but decreased by a factor of several in the past 0.3 Gyr. Most star clusters have a mass between 10{sup 2} and 10{sup 4} M{sub Sun }. The specific star formation rates of {approx}10{sup -16} yr{sup -1} (at the present day) or {approx}10{sup -14} yr{sup -1} (when averaging over the past Gyr) imply that a fraction 10{sup -8} of the stellar mass is younger than 100 Myr and 10{sup -5} is younger than 1 Gyr, quantifying the level of frosting of recent star formation over the otherwise passive stellar population. There is no obvious correlation between either the presence or spatial distribution of postulated star formation indicators and the star formation we detect.

  17. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term

    Office of Scientific and Technical Information (OSTI)

    Maintenance: Final Technical Report (Technical Report) | SciTech Connect High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report Citation Details In-Document Search Title: High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report The Quest Camera was installed at the Palomar Obervatory in California. The camera was used to carry out a survey of low redshift Type 1a supernovae.The

  18. First-Generation Risk Profiles Help Predict CO2 Storage Site Obstacles |

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

    Department of Energy First-Generation Risk Profiles Help Predict CO2 Storage Site Obstacles First-Generation Risk Profiles Help Predict CO2 Storage Site Obstacles September 18, 2012 - 1:00pm Addthis Washington, DC - In support of large-scale carbon capture, utilization and storage (CCUS) projects, a collaboration of five U.S. Department of Energy (DOE) national laboratories has completed first-generation risk profiles that, for the first time, offer a means to predict the probability of

  19. Legal obstacles and incentives to the development of small scale hydroelectric potential in Michigan

    SciTech Connect (OSTI)



    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level is described. The Federal government also exercises extensive regulatory authority in the area. The first obstacle which any developer must confront in Michigan is obtaining the authority to utilize the river bed, banks, and flowing water at a proposed dam site. This involves a determination of ownership of the stream banks and bed, and the manner of obtaining either their title or use; and existing constraints with regard to the use of the water. Michigan follows the riparian theory of water law. The direct regulation; indirect regulation; public utilities regulation; financing; and taxation are discussed.

  20. Non-Economic Obstacles to Wind Deployment: Issues and Regional Differences (Presentation)

    SciTech Connect (OSTI)

    Baring-Gould, I.


    This presentation provides an overview of national obstacles to wind deployment, with regional assessments. A special mention of offshore projects and distributed wind projects is provided. Detailed maps examine baseline capacity, military and flight radar, golden and bald eagle habitat, bat habitat, whooping crane habitat, and public lands. Regional deployment challenges are also discussed.

  1. UCAC4 nearby star survey: A search for our stellar neighbors

    SciTech Connect (OSTI)

    Finch, Charlie T.; Zacharias, Norbert; Subasavage, John P.; Henry, Todd J.; Riedel, Adric R.


    We use data from the U.S. Naval Observatory fourth CCD Astrograph Catalog (UCAC4) in combination with photometry from the AAVSO Photometric All-Sky Survey and Two Micron All-Sky Survey to identify stars within 25 pc of the Sun. A sample of nearby stars with accurate trigonometric parallaxes from the Research Consortium On Nearby Stars is used to generate a set of 16 new photometric color–M{sub K{sub s}} relations that provide distance estimates with uncertainties of 15%. This work expands the available suites of well-calibrated photometric distance relations that can be used to identify nearby stellar systems. The distance relations are used with quality cuts to extract an initial sample of stars from the UCAC4 estimated to be within 25 pc. Color, proper motion, and existing literature sources are then used to obtain a clean sample of red dwarfs, while limiting the amount of contamination from background giants, resulting in a sample of 1761 candidate nearby stars within 25 pc. Of these, 339 are new discoveries with no previously known published parallax or distance estimate, primarily with proper motions less than 0.2 arcsec yr{sup −1}. Five stars are estimated to be within 10 pc, with the nearest, TYC 3980 1081 1, with V=10.50 estimated to be at 5.9 pc. That several hundred new stars have been revealed so close to the Sun illustrates once again that there is considerable work yet to be done to map the solar neighborhood and that additional nearby stars are likely still to be discovered.

  2. Constraints on decaying dark matter from Fermi observations of nearby galaxies and clusters

    SciTech Connect (OSTI)

    Dugger, Leanna; Profumo, Stefano; Jeltema, Tesla E. E-mail:


    We analyze the impact of Fermi gamma-ray observations (primarily non-detections) of selected nearby galaxies, including dwarf spheroidals, and of clusters of galaxies on decaying dark matter models. We show that the fact that galaxy clusters do not shine in gamma rays puts the most stringent limits available to-date on the lifetime of dark matter particles for a wide range of particle masses and decay final states. In particular, our results put strong constraints on the possibility of ascribing to decaying dark matter both the increasing positron fraction reported by PAMELA and the high-energy feature in the electron-positron spectrum measured by Fermi. Observations of nearby dwarf galaxies and of the Andromeda Galaxy (M31) do not provide as strong limits as those from galaxy clusters, while still improving on previous constraints in some cases.

  3. Legal obstacles and incentives to the development of small scale hydroelectric potential in Wisconsin

    SciTech Connect (OSTI)



    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. The initial obstacle that all developers confront in Wisconsin is obtaining the authority to utilize the bed, banks, and flowing water at a proposed dam site. This involves a determination of ownership of the stream banks and bed and the manner of obtaining either their title or use; and existing constraints with regard to the use of the water. Wisconsin follows the riparian theory of water law.

  4. Viscosity Solutions of Systems of PDEs with Interconnected Obstacles and Switching Problem

    SciTech Connect (OSTI)

    Hamadene, S. Morlais, M. A.


    This paper deals with existence and uniqueness of a solution in viscosity sense, for a system of m variational partial differential inequalities with inter-connected obstacles. A particular case is the Hamilton-Jacobi-Bellmann system of the Markovian stochastic optimal m-states switching problem. The switching cost functions depend on (t,x). The main tool is the notion of systems of reflected backward stochastic differential equations with oblique reflection.

  5. Investing in Russia`s oil and gas industry: The legal and bureaucratic obstacles

    SciTech Connect (OSTI)

    Skelton, J.W. Jr.


    This article discusses the unusual challenges the international oil companies have as they consider investing in the oil and gas industry of the Russian Federation. Topics include the following: Russian oil and gas reserves; the Russian legislative process; law on subsurface resources; regulations on licensing procedure; draft law on oil and gas; draft law on concessions; proposed modification draft legislation; obstacles to wide scale investment.


    SciTech Connect (OSTI)

    Schneider, Adam; Song, Inseok; Melis, Carl; Zuckerman, B.; Bessell, Mike E-mail: E-mail:


    It has recently been shown that a significant fraction of late-type members of nearby, very young associations (age {approx}<10 Myr) display excess emission at mid-IR wavelengths indicative of dusty circumstellar disks. We demonstrate that the detection of mid-IR excess emission can be utilized to identify new nearby, young, late-type stars including two definite new members ('TWA 33' and 'TWA 34') of the TW Hydrae Association (TWA). Both new TWA members display mid-IR excess emission in the Wide-field Infrared Survey Explorer catalog and they show proper motion and youthful spectroscopic characteristics-namely, H{alpha} emission, strong lithium absorption, and low surface gravity features consistent with known TWA members. We also detect mid-IR excess-the first unambiguous evidence of a dusty circumstellar disk-around a previously identified UV-bright, young, accreting star (2M1337) that is a likely member of the Lower-Centaurus Crux region of the Scorpius-Centaurus Complex.

  7. Heat loads to divertor nearby components from secondary radiation evolved during plasma instabilities

    SciTech Connect (OSTI)

    Sizyuk, V. Hassanein, A.


    A fundamental issue in tokamak operation related to power exhaust during plasma instabilities is the understanding of heat and particle transport from the core plasma into the scrape-off layer and to plasma-facing materials. During abnormal and disruptive operation in tokamaks, radiation transport processes play a critical role in divertor/edge-generated plasma dynamics and are very important in determining overall lifetimes of the divertor and nearby components. This is equivalent to or greater than the effect of the direct impact of escaped core plasma on the divertor plate. We have developed and implemented comprehensive enhanced physical and numerical models in the upgraded HEIGHTS package for simulating detailed photon and particle transport in the evolved edge plasma during various instabilities. The paper describes details of a newly developed 3D Monte Carlo radiation transport model, including optimization methods of generated plasma opacities in the full range of expected photon spectra. Response of the ITER divertor's nearby surfaces due to radiation from the divertor-developed plasma was simulated by using actual full 3D reactor design and magnetic configurations. We analyzed in detail the radiation emission spectra and compared the emission of both carbon and tungsten as divertor plate materials. The integrated 3D simulation predicted unexpectedly high damage risk to the open stainless steel legs of the dome structure in the current ITER design from the intense radiation during a disruption on the tungsten divertor plate.

  8. The mass of the central black hole in the nearby Seyfert galaxy NGC 5273

    SciTech Connect (OSTI)

    Bentz, Misty C.; Horenstein, Daniel; Bazhaw, Craig; Manne-Nicholas, Emily R.; Ou-Yang, Benjamin J.; Anderson, Matthew; Jones, Jeremy; Norris, Ryan P.; Parks, J. Robert; Saylor, Dicy; Teems, Katherine G.; Turner, Clay


    We present the results of a reverberation-mapping program targeting NGC 5273, a nearby early-type galaxy with a broad-lined active galactic nucleus (AGN). Over the course of the monitoring program, NGC 5273 showed strong variability that allowed us to measure time delays in the responses of the broad optical recombination lines to changes in the continuum flux. A weighted average of these measurements results in a black hole mass determination of M {sub BH} = (4.7 ± 1.6) × 10{sup 6} M {sub ☉}. An estimate of the size of the black hole sphere of influence in NGC 5273 puts it just at the limit of the resolution achievable with current ground-based large aperture telescopes. NGC 5273 is therefore an important future target for a black hole mass determination from stellar dynamical modeling, especially because it is the only nearby early-type galaxy hosting an AGN with a reverberation-based mass, allowing the best comparison for the masses determined from these two techniques.

  9. Tall order in Arizona

    SciTech Connect (OSTI)

    Wright, A.G.


    A 7-year, $470 million project to retrofit scrubber units on a coal-fired power plant is summarized. The scrubbers will be retooled at the 2250-MW Navajo Generating Station in a clean air agreement between the US federal government and Salt River Project. A forced oxidation flue gas desulfurization system was selected for the retrofit; design and construction aspects are summarized in the article. Negotiations between the US Environmental Protection Agency, the Environmental Defense Fund, and the Navajo Nation leading to the retrofit action are also outlined.

  10. Legal obstacles and incentives to the development of small scale hydroelectric power in West Virginia

    SciTech Connect (OSTI)



    The legal and institutional obstacles to the development of small-scale hydroelectric in West Virginia at the state level are described. The Federal government also exercises extensive regulatory authority in the area. The introductory section examines the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and concludes with an inquiry into the practical use of the doctrine by FERC. The development of small-scale hydroelectric energy depends on the selection of a site which will produce sufficient water power capacity to make the project economically attractive to a developer. In West Virginia, the right to use the flowing waters of a stream, creek, or river is appurtenant to the ownership of the lands bordering the watercourse. The lands are known as riparian lands. The water rights are known as riparian rights. Thus, the first obstacle a developer faces involves the acquisition of riparian lands and the subsequent right to the use of the water. The water law in West Virginia is discussed in detail followed by discussions on direct and indirect regulations; continuing obligations; financial considerations; and interstate organizations.

  11. Computational extended magneto-hydrodynamical study of shock structure generated by flows past an obstacle

    SciTech Connect (OSTI)

    Zhao, Xuan; Seyler, C. E.


    The magnetized shock problem is studied in the context where supersonic plasma flows past a solid obstacle. This problem exhibits interesting and important phenomena such as a bow shock, magnetotail formation, reconnection, and plasmoid formation. This study is carried out using a discontinuous Galerkin method to solve an extended magneto-hydrodynamic model (XMHD). The main goals of this paper are to present a reasonably complete picture of the properties of this interaction using the MHD model and then to compare the results to the XMHD model. The inflow parameters, such as the magnetosonic Mach number M{sub f} and the ratio of thermal pressure to magnetic pressure β, can significantly affect the physical structures of the flow-obstacle interaction. The Hall effect can also significantly influence the results in the regime in which the ion inertial length is numerically resolved. Most of the results presented are for the two-dimensional case; however, two three-dimensional simulations are presented to make a connection to the important case in which the solar wind interacts with a solid body and to explore the possibility of performing scaled laboratory experiments.

  12. Correlation of the highest energy cosmic rays with nearby extragalactic objects

    SciTech Connect (OSTI)

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez, C.; Alvarez-Muniz, J.; Ambrosio, M.; /Balseiro Inst., San Carlos de Bariloche /Buenos Aires, CONICET /CNEA, Buenos Aires /Pierre Auger Observ. /La Plata U. /Natl. Tech. U., San Rafael /Adelaide U. /Catholic U. of Bolivia, La Paz /Bolivia U. /Rio de Janeiro, CBPF /Sao Paulo U.


    Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above {approx} 6 x 10{sup 19} eV and the positions of active galactic nuclei (AGN) lying within {approx} 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.

  13. Astrophysical tests of modified gravity: Constraints from distance indicators in the nearby universe

    SciTech Connect (OSTI)

    Jain, Bhuvnesh; Vikram, Vinu; Sakstein, Jeremy


    We use distance measurements in the nearby universe to carry out new tests of gravity, surpassing other astrophysical tests by over two orders of magnitude for chameleon theories. The three nearby distance indicatorscepheids, tip of the red giant branch (TRGB) stars, and water masersoperate in gravitational fields of widely different strengths. This enables tests of scalar-tensor gravity theories because they are screened from enhanced forces to different extents. Inferred distances from cepheids and TRGB stars are altered (in opposite directions) over a range of chameleon gravity theory parameters well below the sensitivity of cosmological probes. Using published data, we have compared cepheid and TRGB distances in a sample of unscreened dwarf galaxies within 10 Mpc. We use a comparable set of screened galaxies as a control sample. We find no evidence for the order unity force enhancements expected in these theories. Using a two-parameter description of the models (the coupling strength and background field value), we obtain constraints on both the chameleon and symmetron screening scenarios. In particular we show that f(R) models with background field values f {sub R0} above 5 10{sup 7} are ruled out at the 95% confidence level. We also compare TRGB and maser distances to the galaxy NGC 4258 as a second test for larger field values. While there are several approximations and caveats in our study, our analysis demonstrates the power of gravity tests in the local universe. We discuss the prospects for additional improved tests with future observations.


    SciTech Connect (OSTI)

    Boyer, Martha L.; Sonneborn, George [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McQuinn, Kristen B. W.; Gehrz, Robert D.; Skillman, Evan [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street SE, University of Minnesota, Minneapolis, MN 55455 (United States); Barmby, Pauline [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada); Bonanos, Alceste Z. [IAASARS, National Observatory of Athens, GR-15236 Penteli (Greece); Gordon, Karl D.; Meixner, Margaret [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Groenewegen, M. A. T. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Lagadec, Eric [Laboratoire Lagrange, UMR7293, Univ. Nice Sophia-Antipolis, CNRS, Observatoire de la Cte d'Azur, F-06300 Nice (France); Lennon, Daniel [ESAEuropean Space Astronomy Centre, Apdo. de Correo 78, E-28691 Villanueva de la Caada, Madrid (Spain); Marengo, Massimo [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Sloan, G. C. [Astronomy Department, Cornell University, Ithaca, NY 14853-6801 (United States); Van Loon, Jacco Th. [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Zijlstra, Albert, E-mail: [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom)


    Nearby resolved dwarf galaxies provide excellent opportunities for studying the dust-producing late stages of stellar evolution over a wide range of metallicity (2.7 ? [Fe/H] ? 1.0). Here, we describe DUSTiNGS (DUST in Nearby Galaxies with Spitzer): a 3.6 and 4.5?m post-cryogen Spitzer Space Telescope imaging survey of 50 dwarf galaxies within 1.5 Mpc that is designed to identify dust-producing asymptotic giant branch (AGB) stars and massive stars. The survey includes 37 dwarf spheroidal, 8 dwarf irregular, and 5 transition-type galaxies. This near-complete sample allows for the building of statistics on these rare phases of stellar evolution over the full metallicity range. The photometry is >75% complete at the tip of the red giant branch for all targeted galaxies, with the exception of the crowded inner regions of IC10, NGC185, and NGC147. This photometric depth ensures that the majority of the dust-producing stars, including the thermally pulsing AGB stars, are detected in each galaxy. The images map each galaxy to at least twice the half-light radius to ensure that the entire evolved star population is included and to facilitate the statistical subtraction of background and foreground contamination, which is severe at these wavelengths. In this overview, we describe the survey, the data products, and preliminary results. We show evidence for the presence of dust-producing AGB stars in eight of the targeted galaxies, with metallicities as low as [Fe/H] = 1.9, suggesting that dust production occurs even at low metallicity.

  15. Oblique solitons generated by the flow of a polariton condensate past an obstacle

    SciTech Connect (OSTI)

    Kamchatnov, A. M. Korneev, S. V.


    The formation of oblique solitons in a polariton condensate flowing past an obstacle is considered. Because of the finite lifetime of polaritons, the condensate flow is inhomogeneous, which leads to a significant modification of the conditions necessary for the generation of oblique solitons as compared to the conditions established earlier for the flow of an atomic condensate. In particular, it is established that oblique solitons in the polariton case can be generated by a subsonic flow of the condensate in agreement with the results of recent experiments [9]. The geometric shape and other parameters of oblique solitons are analytically calculated using a model based on the nonlinear Schroedinger equation with damping, and the analytical results are confirmed by numerical simulations.


    SciTech Connect (OSTI)

    Posselt, B.; Pavlov, G. G.; Popov, S.; Wachter, S.


    Supernova fallback disks around neutron stars have been suspected to influence the evolution of the diverse neutron star populations. Slowly rotating neutron stars are the most promising places to find such disks. Searching for the cold and warm debris of old fallback disks, we carried out Herschel PACS (70 μm, 160 mu m) and Spitzer IRAC (3.6 μm, 4.5 μm) observations of eight slowly rotating (P ≈ 3-11 s) nearby (<1 kpc) isolated neutron stars. Herschel detected 160 μm emission (>5σ) at locations consistent with the positions of the neutron stars RX J0806.4-4123 and RX J2143.0+0654. No other significant infrared emission was detected from the eight neutron stars. We estimate probabilities of 63%, 33%, and 3% that, respectively, none, one, or both Herschel PACS 160 μm detections are unrelated excess sources due to background source confusion or an interstellar cirrus. If the 160 μm emission is indeed related to cold (10-22 K) dust around the neutron stars, this dust is absorbing and re-emitting ∼10% to ∼20% of the neutron stars' X-rays. Such high efficiencies would be at least three orders of magnitude larger than the efficiencies of debris disks around nondegenerate stars. While thin dusty disks around the neutron stars can be excluded as counterparts of the 160 μm emission, dusty asteroid belts constitute a viable option.

  17. Stellar and gaseous nuclear disks observed in nearby (U)LIRGs

    SciTech Connect (OSTI)

    Medling, Anne M.; U, Vivian; Guedes, Javiera; Max, Claire E.; Holden, Bradford; Mayer, Lucio; Roškar, Rok; Armus, Lee; Sanders, David E-mail:


    We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages <30 Myr) and likely formed as gas disks that became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between 10{sup 8} and 10{sup 10} M {sub ☉}, and v/σ between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks that are larger (r {sub eff} ∼ 200-1800 pc) and are likely remnants of the galactic disks that have not yet been completely disrupted by the merger.

  18. Characterizing mid-ultraviolet to optical light curves of nearby type IIn supernovae

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

    de la Rosa, Janie; Roming, Pete; Pritchard, Tyler; Fryer, Chris


    Here, we present early mid-ultraviolet and optical observations of Type IIn supernovae (SNe IIn) observed from 2007 to 2013. Our results focus on the properties of UV light curves: peak absolute magnitudes, temporal decay, and color evolution. During early times, this sample demonstrates that UV light decays faster than optical, and each event transitions from a predominantly UV-bright phase to an optically bright phase. In order to understand early UV behavior, we generate and analyze the sample's blackbody luminosity, temperature, and radius as the SN ejecta expand and cool. Since most of our observations were detected post maximum luminosity, wemore » introduce a method for estimating the date of peak magnitude. When our observations are compared based on filter, we find that even though these SNe IIn vary in peak magnitudes, there are similarities in UV decay rates. We use a simple semi-analytical SN model in order to understand the effects of the explosion environment on our UV observations. Understanding the UV characteristics of nearby SNe IIn during an early phase can provide valuable information about the environment surrounding these explosions, leading us to evaluating the diversity of observational properties in this subclass.« less

  19. The abundance properties of nearby late-type galaxies. I. The data

    SciTech Connect (OSTI)

    Pilyugin, L. S.; Grebel, E. K.; Kniazev, A. Y. E-mail:


    We investigate the oxygen and nitrogen abundance distributions across the optical disks of 130 nearby late-type galaxies using around 3740 published spectra of H II regions. We use these data in order to provide homogeneous abundance determinations for all objects in the sample, including H II regions in which not all of the usual diagnostic lines were measured. Examining the relation between N and O abundances in these galaxies we find that the abundances in their centers and at their isophotal R {sub 25} disk radii follow the same relation. The variation in N/H at a given O/H is around 0.3 dex. We suggest that the observed spread in N/H may be partly caused by the time delay between N and O enrichment and the different star formation histories in galaxies of different morphological types and dimensions. We study the correlations between the abundance properties (central O and N abundances, radial O and N gradients) of a galaxy and its morphological type and dimension.

  20. Alma observations of nearby luminous infrared galaxies with various agn energetic contributions using dense gas tracers

    SciTech Connect (OSTI)

    Imanishi, Masatoshi; Nakanishi, Kouichiro


    We present the results of our ALMA Cycle 0 observations, using HCN/HCO{sup +}/HNC J = 4-3 lines, of six nearby luminous infrared galaxies with various energetic contributions from active galactic nuclei (AGNs) estimated from previous infrared spectroscopy. These lines are very effective for probing the physical properties of high-density molecular gas around the hidden energy sources in the nuclear regions of these galaxies. We find that HCN to HCO{sup +} J = 4-3 flux ratios tend to be higher in AGN-important galaxies than in starburst-dominated regions, as was seen at the J = 1-0 transition, while there is no clear difference in the HCN-to-HNC J = 4-3 flux ratios among observed sources. A galaxy with a starburst-type infrared spectral shape and very large molecular line widths shows a high HCN-to-HCO{sup +} J = 4-3 flux ratio, which could be due to turbulence-induced heating. We propose that enhanced HCN J = 4-3 emission relative to HCO{sup +} J = 4-3 could be used to detect more energetic activity than normal starbursts, including deeply buried AGNs, in dusty galaxy populations.

  1. Discretization error estimation and exact solution generation using the method of nearby problems.

    SciTech Connect (OSTI)

    Sinclair, Andrew J.; Raju, Anil; Kurzen, Matthew J.; Roy, Christopher John; Phillips, Tyrone S.


    The Method of Nearby Problems (MNP), a form of defect correction, is examined as a method for generating exact solutions to partial differential equations and as a discretization error estimator. For generating exact solutions, four-dimensional spline fitting procedures were developed and implemented into a MATLAB code for generating spline fits on structured domains with arbitrary levels of continuity between spline zones. For discretization error estimation, MNP/defect correction only requires a single additional numerical solution on the same grid (as compared to Richardson extrapolation which requires additional numerical solutions on systematically-refined grids). When used for error estimation, it was found that continuity between spline zones was not required. A number of cases were examined including 1D and 2D Burgers equation, the 2D compressible Euler equations, and the 2D incompressible Navier-Stokes equations. The discretization error estimation results compared favorably to Richardson extrapolation and had the advantage of only requiring a single grid to be generated.

  2. Imaging survey of subsystems in secondary components to nearby southern dwarfs

    SciTech Connect (OSTI)

    Tokovinin, Andrei


    To improve the statistics of hierarchical multiplicity, secondary components of wide nearby binaries with solar-type primaries were surveyed at the SOAR telescope for evaluating the frequency of subsystems. Images of 17 faint secondaries were obtained with the SOAR Adaptive Module that improved the seeing; one new 0.''2 binary was detected. For all targets, photometry in the g', i', z' bands is given. Another 46 secondaries were observed by speckle interferometry, resolving 7 close subsystems. Adding literature data, the binarity of 95 secondary components is evaluated. We found that the detection-corrected frequency of secondary subsystems with periods in the well-surveyed range from 10{sup 3} to 10{sup 5} days is 0.21 ± 0.06—same as the normal frequency of such binaries among solar-type stars, 0.18. This indicates that wide binaries are unlikely to be produced by dynamical evolution of N-body systems, but are rather formed by fragmentation.


    SciTech Connect (OSTI)

    Curtis, Jason L.; Wright, Jason T.; Wolfgang, Angie; Brewer, John M.; Johnson, John Asher


    Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H] = +0.07 {+-} 0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g' - i') and Two Micron All Sky Survey (J - K{sub S} ) color-magnitude diagrams, using the {tau}{sup 2} maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t = 2.5 {+-} 0.25 Gyr, m - M = 7.35 {+-} 0.1, and A{sub V} = 0.25 {+-} 0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3 Gyr and 3.25 Gyr, respectively. At {approx}300 pc and {approx}3 Gyr, Ruprecht 147 is by far the oldest nearby star cluster.

  4. Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

    SciTech Connect (OSTI)

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; /Wisconsin U., Milwaukee /Lisbon, IST


    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuzmin energy threshold, 6 x 10{sup 19} eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1{sup o} from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (38{sub -6}{sup +7})%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of (69{sub -13}{sup +11})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.

  5. Antideuteron production in {upsilon}(nS) decays and the nearby continuum

    SciTech Connect (OSTI)

    Asner, D. M.; Edwards, K. W.; Briere, R. A.; Chen, J.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Berkelman, K.; Cassel, D. G.; Duboscq, J. E.; Ecklund, K. M.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, R.


    Using CLEO data, we study the production of the antideuteron, d, in {upsilon}(nS) resonance decays and the nearby continuum. The branching ratios obtained are B{sup dir}({upsilon}(1S){yields}dX)=(3.36{+-}0.23{+-}0.25)x10{sup -5}, B({upsilon}(1S){yields}dX)=(2.86{+-}0.19{+-}0.21)x10{sup -5}, and B({upsilon}(2S){yields}dX)=(3.37{+-}0.50{+-}0.25)x10{sup -5}, where the 'dir' superscript indicates that decays produced via reannihilation of the bb pair to a {gamma}* are removed from both the signal and the normalizing number of {upsilon}(1S) decays in order to isolate direct decays of the {upsilon}(1S) to ggg, gg{gamma}. Upper limits at 90% C.L. are given for B({upsilon}(4S){yields}dX)<1.3x10{sup -5}, and continuum production {sigma}(e{sup +}e{sup -}{yields}dX)<0.031 pb. The {upsilon}(2S) data is also used to extract a limit on {chi}{sub bJ}{yields}dX. The results indicate enhanced deuteron production in ggg, gg{gamma} hadronization compared to {gamma}*{yields}qq. Baryon number compensation is also investigated with the large {upsilon}(1S){yields}dX sample.

  6. Legal obstacles and incentives to the development of small scale hydroelectric power in Maryland

    SciTech Connect (OSTI)



    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level in Maryland are described. The Federal government also exercises extensive regulatory authority in the area. The dual regulatory system is examined with the aim of creating a more orderly understanding of the vagaries of the system, focusing on the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC. In Maryland, by common law rule, title to all navigable waters and to the soil below the high-water mark of those waters is vested in the state as successor to the Lord Proprietary who had received it by grant from the Crown. Rights to non-navigable water, public trust doctrine, and eminent domain are also discussed. Direct and indirect regulations, continuing obligations, loan programs, and regional organizations are described in additional sections.

  7. Legal obstacles and incentives to the development of small scale hydroelectric power in New York

    SciTech Connect (OSTI)



    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory authority in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. The first step the small scale hydroelectric developer must take is that of acquiring title to the real property comprising the development site. The real estate parcel must include the requisite interest in the land adjacent to the watercourse, access to the underlying streambed and where needed, the land necessary for an upstream impoundment area. Land acquisition may be effectuated by purchase, lease, or grant by the state. In addition to these methods, New York permits the use of the eminent domain power of the state for public utilities under certain circumstances.


    SciTech Connect (OSTI)

    Khan, Rubab; Stanek, K. Z.; Kochanek, C. S. E-mail:


    The late-stage evolution of the most massive stars such as {eta} Carinae is controlled by the effects of mass loss, which may be dominated by poorly understood eruptive mass ejections. Understanding this population is challenging because no true analogs of {eta} Car have been clearly identified in the Milky Way or other galaxies. We utilize Spitzer IRAC images of seven nearby ({approx}< 4 Mpc) galaxies to search for such analogs. We find 34 candidates with a flat or rising mid-IR spectral energy distributions toward longer mid-infrared wavelengths that emit >10{sup 5} L{sub Sun} in the IRAC bands (3.6 to 8.0 {mu}m) and are not known to be background sources. Based on our estimates for the expected number of background sources, we expect that follow-up observations will show that most of these candidates are not dust enshrouded massive stars, with an expectation of only 6 {+-} 6 surviving candidates. Since we would detect true analogs of {eta} Car for roughly 200 years post-eruption, this implies that the rate of eruptions like {eta} Car is less than the core-collapse supernova rate. It is possible, however, that every M > 40 M{sub Sun} star undergoes such eruptions given our initial results. In Paper II we will characterize the candidates through further analysis and follow-up observations, and there is no barrier to increasing the galaxy sample by an order of magnitude. The primary limitation of the present search is that Spitzer's resolution limits us to the shorter wavelength IRAC bands. With the James Webb Space Telescope, such surveys can be carried out at the far more optimal wavelengths of 10-30 {mu}m, allowing identification of {eta} Car analogs for millennia rather than centuries post-eruption.


    SciTech Connect (OSTI)

    Gutermuth, R. A.; Pipher, J. L.; Megeath, S. T.; Allen, T. S.; Myers, P. C.; Allen, L. E.


    We report the discovery and characterization of a power-law correlation between the local surface densities of Spitzer-identified, dusty young stellar objects (YSOs) and the column density of gas (as traced by near-IR extinction) in eight molecular clouds within 1 kpc and with 100 or more known YSOs. This correlation, which appears in data smoothed over size scales of {approx}1 pc, varies in quality from cloud to cloud; those clouds with tight correlations, MonR2 and Ophiuchus, are fit with power laws of slope 2.67 and 1.87, respectively. The spread in the correlation is attributed primarily to local gas disruption by stars that formed there or to the presence of very young subregions at the onset of star formation. We explore the ratio of the number of Class II to Class I sources, a proxy for the star formation age of a region, as a function of gas column density; this analysis reveals a declining Class II to Class I ratio with increasing column density. We show that the observed star-gas correlation is consistent with a star formation law where the star formation rate per area varies with the gas column density squared. We also propose a simple picture of thermal fragmentation of dense gas in an isothermal, self-gravitating layer as an explanation for the power law. Finally, we briefly compare the star-gas correlation and its implied star formation law with other recent proposed of star formation laws at similar and larger size scales from nearby star-forming regions.


    SciTech Connect (OSTI)

    Malo, Lison; Doyon, Rene; Lafreniere, David; Artigau, Etienne; Gagne, Jonathan; Baron, Frederique; Riedel, Adric E-mail: E-mail: E-mail:


    We present a new method based on a Bayesian analysis to identify new members of nearby young kinematic groups. The analysis minimally takes into account the position, proper motion, magnitude, and color of a star, but other observables can be readily added (e.g., radial velocity, distance). We use this method to find new young low-mass stars in the {beta} Pictoris and AB Doradus moving groups and in the TW Hydrae, Tucana-Horologium, Columba, Carina, and Argus associations. Starting from a sample of 758 mid-K to mid-M (K5V-M5V) stars showing youth indicators such as H{alpha} and X-ray emission, our analysis yields 214 new highly probable low-mass members of the kinematic groups analyzed. One is in TW Hydrae, 37 in {beta} Pictoris, 17 in Tucana-Horologium, 20 in Columba, 6 in Carina, 50 in Argus, 32 in AB Doradus, and the remaining 51 candidates are likely young but have an ambiguous membership to more than one association. The false alarm rate for new candidates is estimated to be 5% for {beta} Pictoris and TW Hydrae, 10% for Tucana-Horologium, Columba, Carina, and Argus, and 14% for AB Doradus. Our analysis confirms the membership of 58 stars proposed in the literature. Firm membership confirmation of our new candidates will require measurement of their radial velocity (predicted by our analysis), parallax, and lithium 6708 A equivalent width. We have initiated these follow-up observations for a number of candidates, and we have identified two stars (2MASSJ01112542+1526214, 2MASSJ05241914-1601153) as very strong candidate members of the {beta} Pictoris moving group and one strong candidate member (2MASSJ05332558-5117131) of the Tucana-Horologium association; these three stars have radial velocity measurements confirming their membership and lithium detections consistent with young age.

  11. Wide cool and ultracool companions to nearby stars from Pan-STARRS 1

    SciTech Connect (OSTI)

    Deacon, Niall R.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Best, William M. J.; Bowler, Brendan P.; Burgett, William S.; Chambers, Kenneth C.; Flewelling, H.; Kaiser, Nick; Kudritzki, Rolf-Peter; Morgan, Jeff S.; Tonry, John L.; Dupuy, Trent; Mann, Andrew W.; Redstone, Joshua A.; Draper, Peter W.; Metcalfe, Nigel; Hodapp, Klaus W.; Price, Paul A.; and others


    We present the discovery of 57 wide (>5'') separation, low-mass (stellar and substellar) companions to stars in the solar neighborhood identified from Pan-STARRS 1 (PS1) data and the spectral classification of 31 previously known companions. Our companions represent a selective subsample of promising candidates and span a range in spectral type of K7-L9 with the addition of one DA white dwarf. These were identified primarily from a dedicated common proper motion search around nearby stars, along with a few as serendipitous discoveries from our Pan-STARRS 1 brown dwarf search. Our discoveries include 23 new L dwarf companions and one known L dwarf not previously identified as a companion. The primary stars around which we searched for companions come from a list of bright stars with well-measured parallaxes and large proper motions from the Hipparcos catalog (8583 stars, mostly A-K dwarfs) and fainter stars from other proper motion catalogs (79170 stars, mostly M dwarfs). We examine the likelihood that our companions are chance alignments between unrelated stars and conclude that this is unlikely for the majority of the objects that we have followed-up spectroscopically. We also examine the entire population of ultracool (>M7) dwarf companions and conclude that while some are loosely bound, most are unlikely to be disrupted over the course of ?10 Gyr. Our search increases the number of ultracool M dwarf companions wider than 300 AU by 88% and increases the number of L dwarf companions in the same separation range by 82%. Finally, we resolve our new L dwarf companion to HIP 6407 into a tight (0.''13, 7.4 AU) L1+T3 binary, making the system a hierarchical triple. Our search for these key benchmarks against which brown dwarf and exoplanet atmosphere models are tested has yielded the largest number of discoveries to date.


    SciTech Connect (OSTI)

    Trujillo, Ignacio; Vazdekis, Alexandre; Balcells, Marc; Snchez-Blzquez, Patricia


    As early as 10Gyr ago, galaxies with more than 10{sup 11} M {sub ?} of stars already existed. While most of these massive galaxies must have subsequently transformed through on-going star formation and mergers with other galaxies, a small fraction (?0.1%) may have survived untouched until today. Searches for such relic galaxies, useful windows to explore the early universe, have been inconclusive to date: galaxies with masses and sizes like those observed at high redshift (M {sub *} ? 10{sup 11} M {sub ?}; R{sub e} ? 1.5kpc) have been found in the local universe, but their stars are far too young for the galaxy to be a relic galaxy. This paper explores the first case of a nearby galaxy, NGC1277 (at a distance of 73 Mpc in the Perseus galaxy cluster), which fulfills many criteria to be considered a relic galaxy. Using deep optical spectroscopy, we derive the star formation history along the structure of the galaxy: the stellar populations are uniformly old (>10Gyr) with no evidence for more recent star formation episodes. The metallicity of their stars is super-solar ([Fe/H] = 0.20 0.04 with a smooth decline toward the outer regions) and ?-enriched ([?/Fe] = 0.4 0.1). This suggests a very short formation time scale for the bulk of the stars in this galaxy. This object also rotates very fast (V {sub rot} ? 300kms{sup 1}) and has a large central velocity dispersion (? > 300kms{sup 1}). NGC1277 allows the exploration in full detail of properties such as the structure, internal dynamics, metallicity, and initial mass function as they were at ?10-12Gyr ago when the first massive galaxies were built.

  13. Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

    SciTech Connect (OSTI)

    Sanchez-Conde, Miguel A.; Cannoni, Mirco; Zandanel, Fabio; Gomez, Mario E.; Prada, Francisco; /IAA, Granada


    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We


    SciTech Connect (OSTI)

    Torres-Papaqui, J. P.; Coziol, R.; Ortega-Minakata, R. A.; Neri-Larios, D. M. E-mail: E-mail:


    We have determined the metallicity (O/H) and nitrogen abundance (N/O) of a sample of 122,751 star-forming galaxies (SFGs) from the Data Release 7 of the Sloan Digital Sky Survey. For all these galaxies we have also determined their morphology and obtained a comprehensive picture of their star formation history (SFH) using the spectral synthesis code STARLIGHT. The comparison of the chemical abundance with the SFH allows us to describe the chemical evolution of the SFGs in the nearby universe (z {<=} 0.25) in a manner consistent with the formation of their stellar populations and morphologies. A high fraction (45%) of the SFGs in our sample show an excess abundance of nitrogen relative to their metallicity. We also find this excess to be accompanied by a deficiency of oxygen, which suggests that this could be the result of effective starburst winds. However, we find no difference in the mode of star formation of the nitrogen-rich and nitrogen-poor SFGs. Our analysis suggests that they all form their stars through a succession of bursts of star formation extended over a period of few Gyr. What produces the chemical differences between these galaxies seems therefore to be the intensity of the bursts: the galaxies with an excess of nitrogen are those that are presently experiencing more intense bursts or have experienced more intense bursts in their past. We also find evidence relating the chemical evolution process to the formation of the galaxies: the galaxies with an excess of nitrogen are more massive, and have more massive bulges and earlier morphologies than those showing no excess. Contrary to expectation, we find no evidence that the starburst wind efficiency decreases with the mass of the galaxies. As a possible explanation we propose that the loss of metals consistent with starburst winds took place during the formation of the galaxies, when their potential wells were still building up, and consequently were weaker than today, making starburst winds more


    SciTech Connect (OSTI)

    Stocke, John T.; Danforth, Charles W. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Perlman, Eric S., E-mail:, E-mail:, E-mail: [Florida Institute of Technology, Physics and Space Sciences Department, 150 West University Boulevard, Melbourne, FL 32901 (United States)


    We present far-UV HST/COS spectra of four nearby BL Lac objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or narrow-line emission is sometimes seen in high-quality optical spectra. We present detections of Ly{alpha} emission in HST/COS spectra of Mrk 421 (z = 0.030) and PKS 2005-489 (z = 0.071) as well as an archival HST/GHRS observation of Mrk 501 (z = 0.0337). Archival HST/STIS observations of PKS 2155-304 (z = 0.116) show no Ly{alpha} emission to a very low upper limit. Using the assumption that the broad-line region (BLR) clouds are symmetrically placed around the active galactic nucleus (AGN), we use these measured Ly{alpha} emission features to constrain either the relativistic {Gamma} values for the ionizing continuum produced by the jet (in the ionization-bounded case) or the mass of warm gas (in the density-bounded case). While realistic {Gamma} values can be obtained for all four cases, the values for Mrk 421 and PKS 2155-304 are high enough to suggest that covering factors of BLR clouds of {approx}1%-2% might be required to provide consistency with earlier values of Doppler boosting and viewing angles suggested for this class of BL Lacs. This discrepancy also exists in the case of M 87, where the amount of Doppler boosting in our direction is expected to be minimal, again suggestive of a small covering factor of BLR clouds. If, as these small covering factors might suggest, the assumptions of a density-bounded model could be more correct, then the observed Ly{alpha} luminosities require that BL Lac/FR 1 nuclei possess very little warm gas (10{sup -4} to 10{sup -5} M{sub sun}) as suggested by Guilbert et al. If these clouds are in pressure balance with a hotter ({approx}10{sup 6} K) gas, the BLR contains too little mass to power the AGN by accretion alone.


    SciTech Connect (OSTI)

    Rodriguez-Ardila, A.


    The relationship between the emission of coronal lines (CLs) and nuclear activity in 36 Type 1 and 18 Type 2 active galactic nuclei (AGNs) is analyzed, for the first time, based on near-infrared (0.8-2.4 {mu}m) spectra. The eight CLs studied, of Si, S, Fe, Al, and Ca elements and corresponding to ionization potentials (IPs) in the range 125-450 eV, are detected (3{sigma}) in 67% (36 AGNs) of the sample. Our analysis shows that the four most frequent CLs [Si VI] 1.963 {mu}m, [S VIII] 0.9913 {mu}m, [S IX] 1.252 {mu}m, and [Si X] 1.430 {mu}m display a narrow range in luminosity, with most lines located in the interval log L 39-40 erg s{sup -1}. We found that the non-detection is largely associated with either loss of spatial resolution or increasing object distance: CLs are essentially nuclear and easily lose contrast in the continuum stellar light for nearby sources or get diluted by the strong AGN continuum as the redshift increases. Yet, there are AGNs where the lack of coronal emission, i.e., lines with IP {>=} 100 eV, may be genuine. The absence of these lines reflects a non-standard AGN ionizing continuum, namely, a very hard spectrum lacking photons below a few Kev. The analysis of the line profiles points out a trend of increasing FWHM with increasing IPs up to energies around 300 eV, where a maximum in the FWHM is reached. For higher IP lines, the FWHM remains nearly constant or decreases with increasing IPs. We ascribe this effect to an increasing density environment as we approach the innermost regions of these AGNs, where densities above the critical density of the CLs with IPs larger than 300 eV are reached. This sets a strict range limit for the density in the boundary region between the narrow and the broad region of 10{sup 8}-10{sup 9} cm{sup -3}. A relationship between the luminosity of the CLs and that of the soft and hard X-ray emission and the soft X-ray photon index is observed: the coronal emission becomes stronger with both increasing X


    SciTech Connect (OSTI)

    Jiang, Xue-Jian; Gu, Qiusheng; Wang, Zhong; Wang, Junzhi; Zhang, Zhi-Yu


    We present CO J = 2-1 observations toward 32 nearby gas-rich star-forming galaxies selected from the ALFALFA and Wide-field Infrared Survey Explorer (WISE) catalogs, using the Sub-millimeter Telescope (SMT). Our sample is selected to be dominated by intermediate-M {sub *} galaxies. The scaling relations between molecular gas, atomic gas, and galactic properties (stellar mass, NUV – r, and WISE color W3 – W2) are examined and discussed. Our results show the following. (1) In the galaxies with stellar mass M {sub *} ≤10{sup 10} M {sub ☉}, the H I fraction (f {sub H} {sub I} ≡ M {sub H} {sub I}/M {sub *}) is significantly higher than that of more massive galaxies, while the H{sub 2} gas fraction (f{sub H{sub 2}} ≡ M{sub H{sub 2}}/M {sub *}) remains nearly unchanged. (2) Compared to f{sub H{sub 2}}, f {sub H} {sub I} correlates better with both M {sub *} and NUV – r. (3) A new parameter, WISE color W3 – W2 (12-4.6 μm), is introduced, which is similar to NUV – r in tracing star formation activity, and we find that W3 – W2 has a tighter anti-correlation with log f{sub H{sub 2}} than the anti-correlation of (NUV – r)-f {sub H} {sub I}, (NUV – r)-f{sub H{sub 2}}, and (W3 – W2)-f {sub H} {sub I}. This indicates that W3 – W2 can trace the H{sub 2} fraction in galaxies. For the gas ratio M{sub H{sub 2}}/M {sub H} {sub I} , only in the intermediate-M {sub *} galaxies it appears to depend on M {sub *} and NUV – r. We find a tight correlation between the molecular gas mass M{sub H{sub 2}} and 12 μm (W3) luminosities (L {sub 12} {sub μm}), and the slope is close to unity (1.03 ± 0.06) for the SMT sample. This correlation may reflect that the cold gas and dust are well mixed on a global galactic scale. Using the all-sky 12 μm (W3) data available in WISE, this correlation can be used to estimate CO flux for molecular gas observations and can even predict H{sub 2} mass for star-forming galaxies.


    SciTech Connect (OSTI)

    Bundy, Kevin; Bershady, Matthew A.; Wake, David A.; Tremonti, Christy; Diamond-Stanic, Aleksandar M.; Law, David R.; Cherinka, Brian; Yan, Renbin; Snchez-Gallego, Jos R.; Drory, Niv; MacDonald, Nicholas; Weijmans, Anne-Marie; Thomas, Daniel; Masters, Karen; Coccato, Lodovico; Aragn-Salamanca, Alfonso; Avila-Reese, Vladimir; Badenes, Carles; Falcn-Barroso, Jsus; Belfiore, Francesco; and others


    We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 at R ? 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 ({sup 1} per 2'' fiber) at 23 AB mag arcsec{sup 2}, which is typical for the outskirts of MaNGA galaxies. Targets are selected with M {sub *} ? 10{sup 9} M {sub ?} using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6yr.


    SciTech Connect (OSTI)

    Akyuz, A.; Avdan, H.; Kayaci, S.; Ozel, M. E.; Sonbas, E.; Balman, S.


    We present the results of a study of non-nuclear discrete sources in a sample of three nearby spiral galaxies (NGC 4395, NGC 4736, and NGC 4258) based on XMM-Newton archival data supplemented with Chandra data for spectral and timing analyses. A total of 75 X-ray sources have been detected within the D{sub 25} regions of the target galaxies. The large collecting area of XMM-Newton makes the statistics sufficient to obtain spectral fitting for 16 (about 20%) of these sources. Compiling the extensive archival exposures available, we were able to obtain the detailed spectral shapes of diverse classes of point sources. We have also studied temporal properties of these luminous sources. Eleven of them are found to show short-term (less than 80 ks) variation while eight of them show long-term variation within factors of {approx}2-5 during a time interval of {approx}2-12 years. Timing analysis provides strong evidence that most of these sources are accreting X-ray binary systems. One source that has properties different from others was suspected to be a supernova remnant, and our follow-up optical observation confirmed this. Our results indicate that sources within the three nearby galaxies are showing a variety of source populations, including several ultraluminous X-ray sources, X-ray binaries, transients together with a super soft source, and a background active galactic nucleus candidate.


    SciTech Connect (OSTI)

    Trump, Jonathan R.; Fang, Jerome J.; Faber, S. M.; Koo, David C.; Kocevski, Dale D.


    We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements from the Sloan Digital Sky Survey are used to disentangle AGN and galaxy emission, resulting in estimates of uncontaminated galaxy rest-frame color, luminosity, and stellar mass. Broad-line AGNs are distributed throughout the blue cloud and green valley at a given stellar mass, and are much rarer in quiescent (red sequence) galaxies. This is in contrast to the published host galaxy properties of weaker narrow-line AGNs, indicating that broad-line AGNs occur during a different phase in galaxy evolution. More luminous broad-line AGNs have bluer host galaxies, even at fixed mass, suggesting that the same processes that fuel nuclear activity also efficiently form stars. The data favor processes that simultaneously fuel both star formation activity and rapid supermassive black hole accretion. If AGNs cause feedback on their host galaxies in the nearby universe, the evidence of galaxy-wide quenching must be delayed until after the broad-line AGN phase.

  1. Nearby-fluids equilibria. II. Zonal flows in a high-{beta}, self-organized plasma experiment

    SciTech Connect (OSTI)

    Steinhauer, L.C.; Guo, H.Y.


    The field and flow structure observed in a high-{beta} field reversed configuration (FRC) produced in the translation, confinement, and sustainment (TCS) experiment are modeled using the newly developed nearby-fluids equilibrium model. These results are the first evidence that experimental FRCs have complex flows, that is nonrigid rotational flow and poloidal flow, both with maximum speeds nearly half the Alfven speed. The interpretive approach is an innovative 'backwards' method using the nearby-fluids platform for two-fluid equilibria. The most remarkable outcome is the prediction of a poloidal flow structure with significant zonal features. The poloidal flow has never been directly measured in FRCs; thus this discovery results from applying the flowing equilibrium model as an interpretive tool. The poloidal flows explain the unusual toroidal field structure observed in TCS. Zonal features in the rotational flow are also inferred from the unfolding of chord-integrated measurements. The results also indicated that a broad core of the FRC is very close to a minimum energy state.

  2. BANYAN. II. Very low mass and substellar candidate members to nearby, young kinematic groups with previously known signs of youth

    SciTech Connect (OSTI)

    Gagn, Jonathan; Lafrenire, David; Doyon, Ren; Malo, Lison; Artigau, tienne


    We present Bayesian Analysis for Nearby Young AssociatioNs II (BANYAN II), a modified Bayesian analysis for assessing the membership of later-than-M5 objects to any of several Nearby Young Associations (NYAs). In addition to using kinematic information (from sky position and proper motion), this analysis exploits 2MASS-WISE color-magnitude diagrams in which old and young objects follow distinct sequences. As an improvement over our earlier work, the spatial and kinematic distributions for each association are now modeled as ellipsoids whose axes need not be aligned with the Galactic coordinate axes, and we use prior probabilities matching the expected populations of the NYAs considered versus field stars. We present an extensive contamination analysis to characterize the performance of our new method. We find that Bayesian probabilities are generally representative of contamination rates, except when a parallax measurement is considered. In this case contamination rates become significantly smaller and hence Bayesian probabilities for NYA memberships are pessimistic. We apply this new algorithm to a sample of 158 objects from the literature that are either known to display spectroscopic signs of youth or have unusually red near-infrared colors for their spectral type. Based on our analysis, we identify 25 objects as new highly probable candidates to NYAs, including a new M7.5 bona fide member to Tucana-Horologium, making it the latest-type member. In addition, we reveal that a known L2? dwarf is co-moving with a bright M5 dwarf, and we show for the first time that two of the currently known ultra red L dwarfs are strong candidates to the AB Doradus moving group. Several objects identified here as highly probable members to NYAs could be free-floating planetary-mass objects if their membership is confirmed.

  3. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

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

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J. -D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; et al


    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water solublemore » fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode. The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5–99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments. The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5–99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was estimated to be ~ 0.15 for the


    SciTech Connect (OSTI)

    Imanishi, Masatoshi; Imase, Keisuke; Oi, Nagisa; Ichikawa, Kohei


    We present the results of a ground-based, high spatial resolution infrared 18 {mu}m imaging study of nearby luminous infrared galaxies (LIRGs), using the Subaru 8.2 m and Gemini-South 8.1 m telescopes. The diffraction-limited images routinely achieved with these telescopes in the Q band (17-23 {mu}m) allow us to investigate the detailed spatial distribution of infrared emission in these LIRGs. We then investigate whether the emission surface brightnesses are modest, as observed in starbursts, or are so high that luminous active galactic nuclei (AGNs; high emission surface brightness energy sources) are indicated. The sample consists of 18 luminous buried AGN candidates and starburst-classified LIRGs identified in earlier infrared spectroscopy. We find that the infrared 18 {mu}m emission from the buried AGN candidates is generally compact, and the estimated emission surface brightnesses are high, sometimes exceeding the maximum value observed in and theoretically predicted for a starburst phenomenon. The starburst-classified LIRGs usually display spatially extended 18 {mu}m emission and the estimated emission surface brightnesses are modest, within the range sustained by a starburst phenomenon. The general agreement between infrared spectroscopic and imaging energy diagnostic methods suggests that both are useful tools for understanding the hidden energy sources of the dusty LIRG population.

  5. Power line fault current coupling to nearby natural gas pipelines: Volume 3, Analysis of pipeline coating impedance: Final report

    SciTech Connect (OSTI)

    Dabkowski, J.; Frazier, M. J.


    This report is a compilation of results obtained from two research programs. The response of a pipeline and coating at the higher voltage excitation levels encountered under power line fault conditions appears to be dominated by conduction at holiday sites in the coating. A simple analytical model was developed for predicting the resistance of a pipeline coating holiday as a function of the voltage produced across the pipeline coating by a nearby faulted power transmission line. The model was initially validated using coated pipeline samples stressed by a capacitive discharge voltage. Additional validation tests were then performed at the Pacific Gas and Electric Company's High Voltage Engineering Research Facility using high voltage ac waveforms for fault simulation. The principle program objective was to develop, both by laboratory and controlled field testing, an electrical resistance characterization for the pipeline coating as a function of the applied voltage level. The development of this model will allow a more accurate prediction of coupled voltage levels to a pipeline during fault current conditions. 54 figs, 3 tabs.

  6. No X-rays from the very nearby type Ia SN 2014J: Constraints on its environment

    SciTech Connect (OSTI)

    Margutti, R.; Parrent, J.; Kamble, A.; Soderberg, A. M.; Milisavljevic, D.; Drout, M. R.; Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States)


    Deep X-ray observations of the post-explosion environment around the very nearby Type Ia SN 2014J (d{sub L} = 3.5 Mpc) reveal no X-ray emission down to a luminosity L{sub x} < 7 10{sup 36} erg s{sup 1} (0.3-10 keV) at ?t ? 20 days after the explosion. We interpret this limit in the context of inverse Compton emission from upscattered optical photons by the supernova shock and constrain the pre-explosion mass-loss rate of the stellar progenitor system to be M-dot <10{sup ?9} M{sub ?} yr{sup ?1} (for wind velocity v{sub w} = 100 km s{sup 1}). Alternatively, the SN shock might be expanding into a uniform medium with density n{sub CSM} < 3 cm{sup 3}. These results rule out single-degenerate (SD) systems with steady mass loss until the terminal explosion and constrain the fraction of transferred material lost at the outer Lagrangian point to be ?1%. The allowed progenitors are (1) white dwarf-white dwarf progenitors, (2) SD systems with unstable hydrogen burning experiencing recurrent nova eruptions with recurrence time t < 300 yr, and (3) stars where the mass loss ceases before the explosion.


    SciTech Connect (OSTI)

    Warren, B. E.; Wilson, C. D.; Sinukoff, E.; Israel, F. P.; Van der Werf, P. P.; Serjeant, S.; Bendo, G. J.; Clements, D. L.; Brinks, E.; Irwin, J. A.; Knapen, J. H.; Leech, J.; Tan, B. K.; Matthews, H. E.; Muehle, S.; Mortimer, A. M. J.; Petitpas, G.; Spekkens, K.; Tilanus, R. P. J.; Usero, A. E-mail: wilson@physics.mcmaster.c E-mail: israel@strw.leidenuniv.n


    We present the results of large-area {sup 12}CO J = 3-2 emission mapping of three nearby field galaxies, NGC 628, NGC 3521, and NGC 3627, completed at the James Clerk Maxwell Telescope as part of the Nearby Galaxies Legacy Survey. These galaxies all have moderate to strong {sup 12}CO J = 3-2 detections over large areas of the fields observed by the survey, showing resolved structure and dynamics in their warm/dense molecular gas disks. All three galaxies were part of the Spitzer Infrared Nearby Galaxies Survey sample, and as such have excellent published multiwavelength ancillary data. These data sets allow us to examine the star formation properties, gas content, and dynamics of these galaxies on sub-kiloparsec scales. We find that the global gas depletion time for dense/warm molecular gas in these galaxies is consistent with other results for nearby spiral galaxies, indicating this may be independent of galaxy properties such as structures, gas compositions, and environments. Similar to the results from The H I Nearby Galaxy Survey, we do not see a correlation of the star formation efficiency with the gas surface density consistent with the Schmidt-Kennicutt law. Finally, we find that the star formation efficiency of the dense molecular gas traced by {sup 12}CO J = 3-2 is potentially flat or slightly declining as a function of molecular gas density, the {sup 12}CO J = 3-2/J = 1-0 ratio (in contrast to the correlation found in a previous study into the starburst galaxy M83), and the fraction of total gas in molecular form.

  8. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    SciTech Connect (OSTI)

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J. -D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; Weigand, M.; Kilcoyne, A. L. D.; Andreae, M. O.


    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water soluble fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode.

    The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5–99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments.

    The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5–99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was


    SciTech Connect (OSTI)

    Alonso-Herrero, Almudena; Ramos Almeida, Cristina; Mason, Rachel; Asensio Ramos, Andres; Rodriguez Espinosa, Jose Miguel; Perez-Garcia, Ana M.; Roche, Patrick F.; Levenson, Nancy A.; Elitzur, Moshe; Packham, Christopher; Young, Stuart; Diaz-Santos, Tanio


    We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions and ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight constraints on torus model parameters such as the viewing angle i, the radial thickness of the torus Y, the angular size of the cloud distribution {sigma}{sub torus}, and the average number of clouds along radial equatorial rays N{sub 0}. We found that the viewing angle i is not the only parameter controlling the classification of a galaxy into type 1 or type 2. In principle, type 2s could be viewed at any viewing angle i as long as there is one cloud along the line of sight. A more relevant quantity for clumpy media is the probability for an active galactic nucleus (AGN) photon to escape unabsorbed. In our sample, type 1s have relatively high escape probabilities, P{sub esc} {approx} 12%-44%, while type 2s, as expected, tend to have very low escape probabilities. Our fits also confirmed that the tori of Seyfert galaxies are compact with torus model radii in the range 1-6 pc. The scaling of the models to the data also provided the AGN bolometric luminosities L{sub bol}(AGN), which were found to be in good agreement with estimates from the literature. When we combined our sample of Seyfert galaxies with a sample of PG quasars from the literature to span a range of L{sub bol}(AGN) {approx} 10{sup 43}-10{sup 47} erg s{sup -1}, we found plausible evidence of the receding torus. That is, there is a tendency for the torus geometrical covering factor to be lower (f{sub 2} {approx} 0.1-0.3) at high AGN luminosities than at low AGN luminosities (f{sub 2} {approx} 0.9-1 at {approx}10{sup 43}-10{sup 44} erg s{sup -1}). This is because at low AGN luminosities the tori appear to have wider angular sizes (larger {sigma}{sub torus}) and more clouds along radial equatorial rays. We cannot, however, rule out the possibility that this is due to

  10. Nearby Supernova Factory Observations of SN 2005gj: Another TypeIa Supernova in a Massive Circumstellar Envelope

    SciTech Connect (OSTI)

    Aldering, G.; Antilogus, P.; Bailey, S.; Baltay, C.; Bauer, A.; Blanc, N.; Bongard, S.; Copin, Y.; Gangler, E.; Gilles, S.; Kessler, R.; Kocevski, D.; Lee, B.C.; Loken, S.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigaudier, G.; Scalzo, R.; Smadja, G.; Thomas, R.C.; Wang, L.; Weaver, B.A.; Rabinowitz, D.; Bauer, A.


    We report the independent discovery and follow-up observations of supernova 2005gj by the Nearby Supernova Factory. This is the second confirmed case of a ''hybrid'' Type Ia/IIn supernova, which like the prototype SN 2002ic, we interpret as the explosion of a white dwarf interacting with a circumstellar medium. Our early-phase photometry of SN 2005gj shows that the strength of the interaction between the supernova ejecta and circumstellar material is much stronger than for SN 2002ic. Our .rst spectrum shows a hot continuum with broad and narrow H{alpha} emission. Later spectra, spanning over 4 months from outburst, show clear Type Ia features combined with broad and narrow H{gamma}, H{beta},H{alpha} and He I {lambda}{lambda}5876,7065 in emission. At higher resolution, P Cygni profiles are apparent. Surprisingly, we also observe an inverted P Cygni profile for [O III] {lambda}5007. We find that the lightcurve and measured velocity of the unshocked circumstellar material imply mass loss as recently as 8 years ago. This is in contrast to SN 2002ic, for which an inner cavity in the circumstellar material was inferred. Within the context of the thin-shell approximation, the early lightcurve is well-described by a flat radial density profile for the circumstellar material. However, our decomposition of the spectra into Type Ia and shock emission components allows for little obscuration of the supernova, suggesting an aspherical or clumpy distribution for the circumstellar material. We suggest that the emission line velocity profiles arise from electron scattering rather than the kinematics of the shock. This is supported by the inferred high densities, and the lack of evidence for evolution in the line widths. Ground- and space-based photometry, and Keck spectroscopy, of the host galaxy are used to ascertain that the host galaxy has low metallicity (Z/Z{sub {circle_dot}} < 0.3; 95% confidence) and that this galaxy is undergoing a significant star formation event that


    SciTech Connect (OSTI)

    Looper, Dagny L.; Pitts, Mark A.; Bochanski, John J.; Burgasser, Adam J.; Mohanty, Subhanjoy; Mamajek, Eric E.; Faherty, Jacqueline K.; West, Andrew A.


    We report the discovery of TWA 30B, a wide ({approx}3400 AU), co-moving M dwarf companion to the nearby ({approx}42 pc) young star TWA 30. Companionship is confirmed from their statistically consistent proper motions and radial velocities (RVs), as well as a chance alignment probability of only 0.08%. Like TWA 30A, the spectrum of TWA 30B shows signatures of an actively accreting disk (H I and alkali line emission) and forbidden emission lines tracing outflowing material ([O I], [O II], [O III], [S II], and [N II]). We have also detected [C I] emission in the optical data, marking the first such detection of this line in a pre-main-sequence star. Negligible RV shifts in the emission lines relative to the stellar frame of rest ({Delta}V {approx}< 30 km s{sup -1}) indicate that the outflows are viewed in the plane of the sky and that the corresponding circumstellar disk is viewed edge-on. Indeed, TWA 30B appears to be heavily obscured by its disk, given that it is 5 mag fainter than TWA 30A at K band despite having a slightly earlier spectral type (M4 versus M5). The near-infrared spectrum of TWA 30B also evinces an excess that varies on day timescales, with colors that follow classical T Tauri tracks as opposed to variable reddening (as is the case for TWA 30A). Multi-epoch data show this excess to be well modeled by a black body component with temperatures ranging from 630 to 880 K and emitting areas that scale inversely with the temperature. The variable excess may arise from disk structure such as a rim or a warp at the inner disk edge located at a radial distance of {approx}3-5 R{sub sun}. As the second and third closest actively accreting and outflowing stars to the Sun (after TWA 3), TWA 30AB presents an ideal system for a detailed study of star and planetary formation processes at the low-mass end of the hydrogen-burning spectrum.


    SciTech Connect (OSTI)

    Riddle, Reed L.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Tendulkar, Shriharsh P.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C. Jr.; Baranec, Christoph; Law, Nicholas M.; Burse, Mahesh P.; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N.


    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 10{sup 3.5} to 10{sup 5}days is 0.12 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 10{sup 6} to 10{sup 7.5}days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.


    SciTech Connect (OSTI)

    Wong, Tony; Xue, Rui; Bolatto, Alberto D.; Fisher, David B.; Vogel, Stuart N.; Leroy, Adam K.; Blitz, Leo; Rosolowsky, Erik; Bigiel, Frank; Ott, Jrgen; Rahman, Nurur; Walter, Fabian


    We investigate the correlation between CO and H I emission in 18 nearby galaxies from the CARMA Survey Toward IR-Bright Nearby Galaxies (STING) at sub-kpc and kpc scales. Our sample, spanning a wide range in stellar mass and metallicity, reveals evidence for a metallicity dependence of the H I column density measured in regions exhibiting CO emission. Such a dependence is predicted by the equilibrium model of McKee and Krumholz, which balances H{sub 2} formation and dissociation. The observed H I column density is often smaller than predicted by the model, an effect we attribute to unresolved clumping, although values close to the model prediction are also seen. We do not observe H I column densities much larger than predicted, as might be expected were there a diffuse H I component that did not contribute to H{sub 2} shielding. We also find that the H{sub 2} column density inferred from CO correlates strongly with the stellar surface density, suggesting that the local supply of molecular gas is tightly regulated by the stellar disk.


    SciTech Connect (OSTI)

    Vogt, Steven S.; Rivera, E. J.; Haghighipour, N.; Henry, Gregory W.; Williamson, Michael H.


    We present 11 years of HIRES precision radial velocities (RVs) of the nearby M3V star Gliese 581, combining our data set of 122 precision RVs with an existing published 4.3-year set of 119 HARPS precision RVs. The velocity set now indicates six companions in Keplerian motion around this star. Differential photometry indicates a likely stellar rotation period of {approx}94 days and reveals no significant periodic variability at any of the Keplerian periods, supporting planetary orbital motion as the cause of all the RV variations. The combined data set strongly confirms the 5.37-day, 12.9-day, 3.15-day, and 67-day planets previously announced by Bonfils et al., Udry et al., and Mayor et al.. The observations also indicate a fifth planet in the system, GJ 581f, a minimum-mass 7.0 M{sub +} planet orbiting in a 0.758 AU orbit of period 433 days, and a sixth planet, GJ 581g, a minimum-mass 3.1 M{sub +} planet orbiting at 0.146 AU with a period of 36.6 days. The estimated equilibrium temperature of GJ 581g is 228 K, placing it squarely in the middle of the habitable zone of the star and offering a very compelling case for a potentially habitable planet around a very nearby star. That a system harboring a potentially habitable planet has been found this nearby, and this soon in the relatively early history of precision RV surveys, indicates that {eta}{sub +}, the fraction of stars with potentially habitable planets, is likely to be substantial. This detection, coupled with statistics of the incompleteness of present-day precision RV surveys for volume-limited samples of stars in the immediate solar neighborhood, suggests that {eta}{sub +} could well be on the order of a few tens of percent. If the local stellar neighborhood is a representative sample of the galaxy as a whole, our Milky Way could be teeming with potentially habitable planets.


    SciTech Connect (OSTI)

    Boyer, Martha L.; Sonneborn, George; McQuinn, Kristen B. W.; Gehrz, Robert D.; Skillman, Evan; Barmby, Pauline; Bonanos, Alceste Z.; Gordon, Karl D.; Meixner, Margaret; Groenewegen, M. A. T.; Lagadec, Eric; Lennon, Daniel; Marengo, Massimo; McDonald, Iain; Zijlstra, Albert; Sloan, G. C.; Van Loon, Jacco Th.


    The DUSTiNGS survey (DUST in Nearby Galaxies with Spitzer) is a 3.6 and 4.5 μm imaging survey of 50 nearby dwarf galaxies designed to identify dust-producing asymptotic giant branch (AGB) stars and massive stars. Using two epochs, spaced approximately six months apart, we identify a total of 526 dusty variable AGB stars (sometimes called ''extreme'' or x-AGB stars; [3.6]-[4.5] > 0.1 mag). Of these, 111 are in galaxies with [Fe/H] < –1.5 and 12 are in galaxies with [Fe/H] < –2.0, making them the most metal-poor dust-producing AGB stars known. We compare these identifications to those in the literature and find that most are newly discovered large-amplitude variables, with the exception of ≈30 stars in NGC 185 and NGC 147, 1 star in IC 1613, and 1 star in Phoenix. The chemical abundances of the x-AGB variables are unknown, but the low metallicities suggest that they are more likely to be carbon-rich than oxygen-rich and comparisons with existing optical and near-IR photometry confirm that 70 of the x-AGB variables are confirmed or likely carbon stars. We see an increase in the pulsation amplitude with increased dust production, supporting previous studies suggesting that dust production and pulsation are linked. We find no strong evidence linking dust production with metallicity, indicating that dust can form in very metal-poor environments.


    SciTech Connect (OSTI)

    Gagn, Jonathan; Lafrenire, David; Doyon, Ren; Malo, Lison; Artigau, tienne


    We present the BANYAN All-Sky Survey (BASS) catalog, consisting of 228 new late-type (M4-L6) candidate members of nearby young moving groups (YMGs) with an expected false-positive rate of ?13%. This sample includes 79 new candidate young brown dwarfs and 22 planetary-mass objects. These candidates were identified through the first systematic all-sky survey for late-type low-mass stars and brown dwarfs in YMGs. We cross-matched the Two Micron All Sky Survey and AllWISE catalogs outside of the galactic plane to build a sample of 98,970 potential ?M5 dwarfs in the solar neighborhood and calculated their proper motions with typical precisions of 5-15 mas yr{sup 1}. We selected highly probable candidate members of several YMGs from this sample using the Bayesian Analysis for Nearby Young AssociatioNsII tool (BANYANII). We used the most probable statistical distances inferred from BANYANII to estimate the spectral type and mass of these candidate YMG members. We used this unique sample to show tentative signs of mass segregation in the AB Doradus moving group and the Tucana-Horologium and Columba associations. The BASS sample has already been successful in identifying several new young brown dwarfs in earlier publications, and will be of great interest in studying the initial mass function of YMGs and for the search of exoplanets by direct imaging; the input sample of potential close-by ?M5 dwarfs will be useful to study the kinematics of low-mass stars and brown dwarfs and search for new proper motion pairs.


    SciTech Connect (OSTI)

    Doi, Akihiro; Asada, Keiichi; Inoue, Makoto; Fujisawa, Kenta; Nagai, Hiroshi; Hagiwara, Yoshiaki; Wajima, Kiyoaki


    We conducted Very Long Baseline Array (VLBA) observations of seven nearby narrow-line Seyfert 1 (NLS1) galaxies at 1.7 GHz ({lambda}18 cm) with milliarcsecond resolution. This is the first systematic very long baseline interferometry study focusing on the central parsec-scale regions of radio-quiet NLS1s. Five of the seven were detected at a brightness temperature of {approx}> 5 Multiplication-Sign 10{sup 6} K and contain radio cores with high brightness temperatures of >6 Multiplication-Sign 10{sup 7} K, indicating a nonthermal process driven by jet-producing central engines as in radio-loud NLS1s and other active galactic nucleus classes. VLBA images of MRK 1239, MRK 705, and MRK 766 exhibit parsec-scale jets with clear linear structures. A large portion of the radio power comes from diffuse emission components that are distributed within the nuclear regions ({approx}< 300 pc), which is a common characteristic throughout the observed NLS1s. Jet kinetic powers limited by the Eddington limit may be insufficient to allow the jets to escape to kiloparsec scales for these radio-quiet NLS1s with low-mass black holes of {approx}< 10{sup 7} M {sub Sun }.

  18. Star formation properties in barred galaxies. III. Statistical study of bar-driven secular evolution using a sample of nearby barred spirals

    SciTech Connect (OSTI)

    Zhou, Zhi-Min; Wu, Hong; Cao, Chen E-mail:


    Stellar bars are important internal drivers of secular evolution in disk galaxies. Using a sample of nearby spiral galaxies with weak and strong bars, we explore the relationships between the star formation feature and stellar bars in galaxies. We find that galaxies with weak bars tend coincide with low concentrical star formation activity, while those with strong bars show a large scatter in the distribution of star formation activity. We find enhanced star formation activity in bulges toward stronger bars, although not predominantly, consistent with previous studies. Our results suggest that different stages of the secular process and many other factors may contribute to the complexity of the secular evolution. In addition, barred galaxies with intense star formation in bars tend to have active star formation in their bulges and disks, and bulges have higher star formation densities than bars and disks, indicating the evolutionary effects of bars. We then derived a possible criterion to quantify the different stages of the bar-driven physical process, while future work is needed because of the uncertainties.

  19. Federal legal obstacles and incentives to the development of the small-scale hydroelectric potential of the nineteen Northeastern states. Executive summary

    SciTech Connect (OSTI)



    The main report for which this report is the executive summary, DOE/RA--23-216.00.0-01 (see EAPA 5:3929), was published in revised form in March 1979. Also, since that time, Energy Law Institute has produced detailed legal memoranda on obstacles and incentives for each of the 19 states. This executive summary summarizes the findings and observations of the original report. Specific summaries included are: Federal Jurisdiction Over Small-Scale Hydroelectric Facilities; The FERC; The Regulation of Construction in and the Discharge of Dredged, Fill, and Other Materials into the Waters of the US; The Protection of Fish, Wildlife, and Endangered Species; The Preservation of Historic Places, Archaeological Sites, and Natural Areas; Regulation of the Use of Federal Lands; Federal Dam Construction and Power-Distribution Agencies; Additional Federal Agencies Concerned with Small-Scale Hydroelectric Dams; Federal Tax Devices and Business Structures Affecting Small-Scale Hydroelectric Development; and an Outline of Federal-Assistance programs Available for Small-Scale Hydroelectric Development.


    SciTech Connect (OSTI)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Deacon, Niall R.; Dupuy, Trent J.; Redstone, Joshua; Price, P. A.


    We present initial results from a wide-field (30,000 deg{sup 2}) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and Wide-field Infrared Survey Explorer (WISE) surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because these objects are faint in optical bands and have near-infrared (near-IR) colors that are difficult to distinguish from background stars. To overcome these obstacles, we have cross-matched the Pan-STARRS1 (optical) and WISE (mid-IR) catalogs to produce a unique multi-wavelength database for finding ultracool dwarfs. As part of our initial discoveries, we have identified seven brown dwarfs in the L/T transition within 9-15 pc of the Sun. The L9.5 dwarf PSO J140.2308+45.6487 and the T1.5 dwarf PSO J307.6784+07.8263 (both independently discovered by Mace et al.) show possible spectroscopic variability at the Y and J bands. Two more objects in our sample show evidence of photometric J-band variability, and two others are candidate unresolved binaries based on their spectra. We expect our full search to yield a well-defined, volume-limited sample of L/T transition dwarfs that will include many new targets for study of this complex regime. PSO J307.6784+07.8263 in particular may be an excellent candidate for in-depth study of variability, given its brightness (J = 14.2 mag) and proximity (11 pc)


    SciTech Connect (OSTI)

    Fortney, Jonathan J.


    Recent high-resolution spectroscopic analysis of nearby FGK stars suggests that a high C/O ratio of greater than 0.8, or even 1.0, is relatively common. Two published catalogs find C/O > 0.8 in 25%-30% of systems, and C/O > 1.0 in {approx}6%-10%. It has been suggested that in protoplanetary disks with C/O > 0.8 that the condensation pathways to refractory solids will differ from what occurred in our solar system, where C/O = 0.55. The carbon-rich disks are calculated to make carbon-dominated rocky planets, rather than oxygen-dominated ones. Here we suggest that the derived stellar C/O ratios are overestimated. One constraint on the frequency of high C/O is the relative paucity of carbon dwarf stars (10{sup -3}-10{sup -5}) found in large samples of low-mass stars. We suggest reasons for this overestimation, including a high C/O ratio for the solar atmosphere model used for differential abundance analysis, the treatment of a Ni blend that affects the O abundance, and limitations of one-dimensional LTE stellar atmosphere models. Furthermore, from the estimated errors on the measured stellar C/O ratios, we find that the significance of the high C/O tail is weakened, with a true measured fraction of C/O > 0.8 in 10%-15% of stars, and C/O > 1.0 in 1%-5%, although these are still likely overestimates. We suggest that infrared T-dwarf spectra could show how common high C/O is in the stellar neighborhood, as the chemistry and spectra of such objects would differ compared to those with solar-like abundances. While possible at C/O > 0.8, we expect that carbon-dominated rocky planets are rarer than others have suggested.


    SciTech Connect (OSTI)

    Kniazev, A. Y.; Vaisanen, P.; Potter, S. B.; Crawford, S.; Gulbis, A. A. S.; Muzic, K.; Mehner, A.; Boffin, H. M. J.; Melo, C.; Ivanov, V. D.; Girard, J.; Mawet, D.; Schmidtobreick, L.; Kurtev, R.; Borissova, J.; Huelamo, N.; Minniti, D.; Ishibashi, K.; Beletsky, Y.; Buckley, D. A. H.; and others


    WISE J104915.57-531906.1 is a L/T brown dwarf binary located 2 pc from the Sun. The pair contains the closest known brown dwarfs and is the third closest known system, stellar or sub-stellar. We report comprehensive follow-up observations of this newly uncovered system. We have determined the spectral types of both components (L8 {+-} 1, for the primary, agreeing with the discovery paper; T1.5 {+-} 2 for the secondary, which was lacking spectroscopic type determination in the discovery paper) and, for the first time, their radial velocities (V{sub rad} {approx} 23.1, 19.5 km s{sup -1}) using optical spectra obtained at the Southern African Large Telescope and other facilities located at the South African Astronomical Observatory (SAAO). The relative radial velocity of the two components is smaller than the range of orbital velocities for theoretically predicted masses, implying that they form a gravitationally bound system. We report resolved near-infrared JHK{sub S} photometry from the Infrared Survey Facility telescope at the SAAO which yields colors consistent with the spectroscopically derived spectral types. The available kinematic and photometric information excludes the possibility that the object belongs to any of the known nearby young moving groups or associations. Simultaneous optical polarimetry observations taken at the SAAO 1.9 m give a non-detection with an upper limit of 0.07%. For the given spectral types and absolute magnitudes, 1 Gyr theoretical models predict masses of 0.04-0.05 M{sub Sun} for the primary, and 0.03-0.05 M{sub Sun} for the secondary.


    SciTech Connect (OSTI)

    Marino, R. A.; Gil de Paz, A.; Castillo-Morales, A.; Perez-Gonzalez, P. G.; Gallego, J.; Zamorano, J.; Sanchez, S. F.


    We present an analysis of the full bidimensional optical spectral cube of the nearby spiral galaxy NGC 5668, observed with the Pmas fiber PAcK Integral Field Unit (IFU) at the Calar Alto observatory 3.5 m telescope. We make use of broadband imaging to provide further constraints on the evolutionary history of the galaxy. This data set will allow us to improve our understanding of the mechanisms that drive the evolution of disks. We investigated the properties of 62 H II regions and concentric rings in NGC 5668 and derived maps in ionized-gas attenuation and chemical (oxygen) abundances. We find that while inward of r {approx}36'' {approx} 4.4 kpc {approx} 0.36 (D{sub 25}/2) the derived O/H ratio follows the radial gradient typical of spiral galaxies, the abundance gradient beyond r {approx} 36'' flattens out. The analysis of the multi-wavelength surface brightness profiles of NGC 5668 is performed by fitting these profiles with those predicted by chemo-spectrophotometric evolutionary models of galaxy disks. From this, we infer a spin and circular velocity of {lambda} = 0.053 and v{sub c} = 167 km s{sup -1}, respectively. The metallicity gradient and rotation curve predicted by this best-fitting galaxy model nicely match the values derived from the IFU observations, especially within r {approx}36''. The same is true for the colors despite some small offsets and a reddening in the bluest colors beyond that radius. On the other hand, deviations of some of these properties in the outer disk indicate that a secondary mechanism, possibly gas transfer induced by the presence of a young bar, must have played a role in shaping the recent chemical and star formation histories of NGC 5668.

  4. Investigating nearby star-forming galaxies in the ultraviolet with HST/COS spectroscopy. I. Spectral analysis and interstellar abundance determinations

    SciTech Connect (OSTI)

    James, B. L.; Aloisi, A.; Sohn, S. T.; Wolfe, M. A.; Heckman, T.


    This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of nine nearby star-forming galaxies. The goal is to assess the (in)homogeneities of the multiphase ISM in galaxies where the bulk of metals can be hidden in the neutral phase, yet the metallicity is inferred from the ionized gas in the H II regions. The sample, spanning a wide range in physical properties, is to date the best suited to investigate the metallicity behavior of the neutral gas at redshift z = 0. ISM absorption lines were detected against the far-ultraviolet spectra of the brightest star-forming region(s) within each galaxy. Here we report on the observations, data reduction, and analysis of these spectra. Column densities were measured by a multicomponent line-profile fitting technique, and neutral-gas abundances were obtained for a wide range of elements. Several caveats were considered, including line saturation, ionization corrections, and dust depletion. Ionization effects were quantified with ad hoc CLOUDY models reproducing the complex photoionization structure of the ionized and neutral gas surrounding the UV-bright sources. An 'average spectrum of a redshift z = 0 star-forming galaxy' was obtained from the average column densities of unsaturated profiles of neutral-gas species. This template can be used as a powerful tool for studies of the neutral ISM at both low and high redshift.


    SciTech Connect (OSTI)

    Anglada-Escude, Guillem; Butler, R. Paul; Arriagada, Pamela; Minniti, Dante; Vogt, Steven S.; Rivera, Eugenio J.; Haghighipour, Nader; Carter, Brad D.; Tinney, C. G.; Wittenmyer, Robert A.; Bailey, Jeremy A.; O'Toole, Simon J.; Jones, Hugh R. A.; Jenkins, James S.


    We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the European Southern Observatory public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/Planet Finder Spectrograph and Keck/High Resolution Echelle Spectrometer spectrometers reveals three additional signals beyond the previously reported 7.2 day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (period {approx}10 years). The 28 day signal implies a planet candidate with a minimum mass of 4.5 M{sub Circled-Plus} orbiting well within the canonical definition of the star's liquid water habitable zone (HZ), that is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition, and interior dynamics. The 75 day signal is less certain, being significantly affected by aliasing interactions among a potential 91 day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal-poor compared to the Sun. The presence of a super-Earth in the HZ of a metal-poor M dwarf in a triple star system supports the evidence that such worlds should be ubiquitous in the Galaxy.

  6. Vision-based obstacle avoidance

    DOE Patents [OSTI]

    Galbraith, John


    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.


    SciTech Connect (OSTI)

    Khan, Rubab; Kochanek, C. S.; Stanek, K. Z.; Gerke, Jill


    Understanding the late-stage evolution of the most massive stars such as η Carinae is challenging because no true analogs of η Car have been clearly identified in the Milky Way or other galaxies. In Khan et al., we utilized Spitzer IRAC images of 7 nearby (≲ 4 Mpc) galaxies to search for such analogs, and found 34 candidates with flat or red mid-IR spectral energy distributions. Here, in Paper II, we present our characterization of these candidates using multi-wavelength data from the optical through the far-IR. Our search detected no true analogs of η Car, which implies an eruption rate that is a fraction 0.01 ≲ F ≲ 0.19 of the core-collapse supernova (ccSN) rate. This is roughly consistent with each M {sub ZAMS} ≳ 70 M {sub ☉} star undergoing one or two outbursts in its lifetime. However, we do identify a significant population of 18 lower luminosity (log (L/L {sub ☉}) ≅ 5.5-6.0) dusty stars. Stars enter this phase at a rate that is a fraction 0.09 ≲ F ≲ 0.55 of the ccSN rate, and this is consistent with all 25 < M {sub ZAMS} < 60 M {sub ☉} stars undergoing an obscured phase at most lasting a few thousand years once or twice. These phases constitute a negligible fraction of post-main-sequence lifetimes of massive stars, which implies that these events are likely to be associated with special periods in the evolution of the stars. The mass of the obscuring material is of order ∼M {sub ☉}, and we simply do not find enough heavily obscured stars for theses phases to represent more than a modest fraction (∼10% not ∼50%) of the total mass lost by these stars. In the long term, the sources that we identified will be prime candidates for detailed physical analysis with the James Webb Space Telescope.

  8. Star formation relations in nearby molecular clouds

    SciTech Connect (OSTI)

    Evans, Neal J. II; Heiderman, Amanda; Vutisalchavakul, Nalin


    We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time, calculated from the mean cloud density, shows no significant correlation. If a crossing time is substituted for the free-fall time, there is even less correlation. Within a cloud, the star formation rate volume and surface densities increase rapidly with the corresponding gas densities, faster than predicted by models using the free-fall time defined from the local density. A model in which the star formation rate depends linearly on the mass of gas above a visual extinction of 8 mag describes the data on these clouds, with very low dispersion. The data on regions of very massive star formation, with improved star formation rates based on free-free emission from ionized gas, also agree with this linear relation.


    SciTech Connect (OSTI)

    Kim, D.-C.; Evans, A. S.; Privon, G. C. E-mail:; and others


    A Hubble Space Telescope/Advanced Camera for Surveys study of the structural properties of 85 luminous and ultraluminous (L{sub IR} > 10{sup 11.4} L{sub Sun }) infrared galaxies (LIRGs and ULIRGs) in the Great Observatories All-sky LIRG Survey (GOALS) sample is presented. Two-dimensional GALFIT analysis has been performed on F814W ''I-band'' images to decompose each galaxy, as appropriate, into bulge, disk, central point-spread function (PSF) and stellar bar components. The fraction of bulge-less disk systems is observed to be higher in LIRGs (35%) than in ULIRGs (20%), with the disk+bulge systems making up the dominant fraction of both LIRGs (55%) and ULIRGs (45%). Further, bulge+disk systems are the dominant late-stage merger galaxy type and are the dominant type for LIRGs and ULIRGs at almost every stage of galaxy-galaxy nuclear separation. The mean I-band host absolute magnitude of the GOALS galaxies is -22.64 {+-} 0.62 mag (1.8{sup +1.4}{sub -0.4} L{sup *}{sub I}), and the mean bulge absolute magnitude in GOALS galaxies is about 1.1 mag fainter than the mean host magnitude. Almost all ULIRGs have bulge magnitudes at the high end (-20.6 to -23.5 mag) of the GOALS bulge magnitude range. Mass ratios in the GOALS binary systems are consistent with most of the galaxies being the result of major mergers, and an examination of the residual-to-host intensity ratios in GOALS binary systems suggests that smaller companions suffer more tidal distortion than the larger companions. We find approximately twice as many bars in GOALS disk+bulge systems (32.8%) than in pure-disk mergers (15.9%) but most of the disk+bulge systems that contain bars are disk-dominated with small bulges. The bar-to-host intensity ratio, bar half-light radius, and bar ellipticity in GOALS galaxies are similar to those found in nearby spiral galaxies. The fraction of stellar bars decreases toward later merger stages and smaller nuclear separations, indicating that bars are destroyed as the merger

  10. Tall and Skinny QR factorizations in MapReduce architectures...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: MapReduce 2011 held June 8, 2011 in San Jose, CA.; Related Information: Proposed for presentation at the MapReduce 2011 held June 8, 2011 in San ...

  11. Scientific American: "Tall Trees Sucked Dry by Global Warming...

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

    ... The New York Times covers "National Labs Race to Stop Iran" The New York Times covers "National Labs Race to Stop Iran" May, 15 2015 - Given the stakes in the sensitive ...

  12. Evaluation of Gas Retention in Waste Simulants: Tall Column Experiments

    SciTech Connect (OSTI)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Shimskey, Rick W.; Denslow, Kayte M.; Powell, Michael R.; Boeringa, Gregory K.; Bontha, Jagannadha R.; Karri, Naveen K.; Fifield, Leonard S.; Tran, Diana N.; Sande, Susan; Heldebrant, David J.; Meacham, Joseph E.; Smet, Dave; Bryan, Wesley E.; Calmus, Ronald B.


    Gas generation in Hanford’s underground waste storage tanks can lead to gas accumulation within the layer of settled solids (sludge) at the tank bottom. The gas, which typically has hydrogen as the major component together with other flammable species, is formed principally by radiation-driven chemical reactions. Accumulation of these gases within the sludge in a waste tank is undesirable and limits the amount of tank volume for waste storage. Further, accumulation of large amounts of gas in the sludge may potentially result in an unacceptable release of the accumulated gas if the sludge-layer density is reduced to less than that of the overlying sludge or that of the supernatant liquid. Rapid release of large amounts of flammable gases could endanger personnel and equipment near the tank. For this reason, a thorough understanding of the circumstances that can lead to a potentially problematic gas accumulation in sludge layers is needed. To respond to this need, the Deep Sludge Gas Release Event Program (DSGREP) was commissioned to examine gas release behavior in sludges.

  13. Factors affecting coking pressures in tall coke ovens

    SciTech Connect (OSTI)

    Grimley, J.J.; Radley, C.E.


    The detrimental effects of excessive coking pressures, resulting in the permanent deformation of coke oven walls, have been recognized for many years. Considerable research has been undertaken worldwide in attempts to define the limits within which a plant may safely operate and to quantify the factors which influence these pressures. Few full scale techniques are available for assessing the potential of a coal blend for causing wall damage. Inference of dangerous swelling pressures may be made however by the measurement of the peak gas pressure which is generated as the plastic layers meet and coalesce at the center of the oven. This pressure is referred to in this report as the carbonizing pressure. At the Dawes Lane cokemaking plant of British Steel`s Scunthorpe Works, a large database has been compiled over several years from the regulator measurement of this pressure. This data has been statistically analyzed to provide a mathematical model for predicting the carbonizing pressure from the properties of the component coals, the results of this analysis are presented in this report.

  14. Obstacle to populating the string theory landscape

    SciTech Connect (OSTI)

    Johnson, Matthew C; Larfors, Magdalena


    We construct domain walls and instantons in a class of models with coupled scalar fields, determining, in agreement with previous studies, that many such solutions contain naked timelike singularities. Vacuum bubble solutions of this type do not contain a region of true vacuum, obstructing the ability of eternal inflation to populate other vacua. We determine a criterion that potentials must satisfy to avoid the existence of such singularities and show that many domain wall solutions in type IIB string theory are singular.

  15. Native American Housing: Obstacles and Opportunities

    Broader source: [DOE]

    Hosted by the U.S. Department of Housing and Urban Development (HUD), this event will cover tribal housing and how to develop and implement programs based on and conducive to local conditions and...

  16. Obstacles to applications of nanostructured thermoelectrics....

    Office of Scientific and Technical Information (OSTI)

    Language: English Word Cloud More Like This Full Text Journal Articles Find in Google Scholar Find in Google Scholar Search WorldCat Search WorldCat to find libraries that may hold ...

  17. Long range hopping mobility platform.

    SciTech Connect (OSTI)

    Spletzer, Barry Louis; Fischer, Gary John


    Sandia National Laboratories has developed a mesoscale hopping mobility platform (Hopper) to overcome the longstanding problems of mobility and power in small scale unmanned vehicles. The system provides mobility in situations such as negotiating tall obstacles and rough terrain that are prohibitive for other small ground base vehicles. The Defense Advanced Research Projects Administration (DARPA) provided the funding for the hopper project.

  18. Fusion of calcium isotopes and of nearby systems

    SciTech Connect (OSTI)

    Stefanini, A. M.


    Very recent data on {sup 40,48}Ca+{sup 40,48}Ca are presented. In all cases fusion hindrance far below the barrier has been observed. Coupled-channel effects influence the threshold energy for hindrance. The excitation functions of the two symmetric systems are similar, while the case of {sup 40}Ca+{sup 48}Ca is different both above and below the barrier, possibly due to couplings to transfer channels with Q > 0. Other systems in the same mass region show different trends that have to be related to the nuclear structure of the colliding nuclei. Investigating the behavior of lighter systems will be interesting also from the astrophysical point of view.


    SciTech Connect (OSTI)

    Schneider, Adam; Song, Inseok; Hufford, Tara; Melis, Carl; Zuckerman, B.; Bessell, Mike; Hinkley, Sasha E-mail: E-mail: E-mail:


    We report an in-depth study of the F8-type star HD 166191, identified in an ongoing survey for stars exhibiting infrared emission above their expected photospheres in the Wide-field Infrared Survey Explorer all-sky catalog. The fractional IR luminosity measured from 3.5 to 70 μm is exceptionally high (L{sub IR}/L{sub bol} ∼ 10%). Near-diffraction-limited imaging observations with the T-ReCS Si filter set on the Gemini South telescope and adaptive optics imaging with the NIRC2 Lp filter on the Keck II telescope confirmed that the excess emission coincides with the star. Si-band images show a strong solid-state emission feature at ∼10 μm. Theoretical evolutionary isochrones and optical spectroscopic observations indicate a stellar age in the range 10-100 Myr. The large dust mass seen in HD 166191's terrestrial planet zone is indicative of a recent collision between planetary embryos or massive ongoing collisional grinding associated with planet building.

  20. The Nearby Supernova Factory: Toward A High-Precision Spectro...

    Office of Scientific and Technical Information (OSTI)

    The goal is to acquire for each supernova and over its full life-time (more than 10 epochs) high spectro-photometric quality spectra over the extended optical range (320-1000 nm).I ...


    SciTech Connect (OSTI)

    Tokovinin, Andrei; Hartung, Markus; Hayward, Thomas L.; Makarov, Valeri V. E-mail: E-mail:


    A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67 pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than expected from binary statistics. About 10% of astrometric companions could be 'dark' (white dwarfs and close pairs of late M-dwarfs). To our surprise, several binaries are found with companions too wide to explain the acceleration. Re-analysis of selected intermediate astrometric data shows that some acceleration solutions in the original Hipparcos catalog are spurious.

  2. The Nearby Supernova Factory: Toward A High-Precision Spectro...

    Office of Scientific and Technical Information (OSTI)

    P. ; Perlmutter, S. ; Runge, K. more ; Thomas, R. ; Weaver, B. ; Baltay, C. ; Bauer, A. ; Rabinowitz, D. ; Scalzo, R. less Publication Date: 2007-07-01 OSTI Identifier: ...


    Office of Scientific and Technical Information (OSTI)


  4. Supernova Discoveries from the Nearby Supernova Factory (SNfactory...

    Office of Scientific and Technical Information (OSTI)

    data on more Type Ia supernovae than have ever been studied in a single project before, and in so doing, to answer some fundamental questions about the nature of the universe. ...


    SciTech Connect (OSTI)

    Tyler, K. D.; Rieke, G. H.; Bai, L.


    Dense environments are known to quench star formation in galaxies, but it is still unknown what mechanism(s) are directly responsible. In this paper, we study the star formation of galaxies in A2029 and compare it to that of Coma, combining indicators at 24 {mu}m, H{alpha}, and UV down to rates of 0.03 M{sub Sun} yr{sup -1}. We show that A2029's star-forming galaxies follow the same mass-SFR relation as the field. The Coma cluster, on the other hand, has a population of galaxies with star formation rates (SFRs) significantly lower than the field mass-SFR relation, indicative of galaxies in the process of being quenched. Over half of these galaxies also host active galactic nuclei. Ram-pressure stripping and starvation/strangulation are the most likely mechanisms for suppressing the star formation in these galaxies, but we are unable to disentangle which is dominating. The differences we see between the two clusters' populations of star-forming galaxies may be related to their accretion histories, with A2029 having accreted its star-forming galaxies more recently than Coma. Additionally, many early-type galaxies in A2029 are detected at 24 {mu}m and/or in the far-UV, but this emission is not directly related to star formation. Similar galaxies have probably been classified as star forming in previous studies of dense clusters, possibly obscuring some of the effects of the cluster environment on true star-forming galaxies.

  6. Manipulating Josephson junctions in thin-films by nearby vortices

    SciTech Connect (OSTI)

    Kogan, V G; Mints, R G


    It is shown that a vortex trapped in one of the banks of a planar edge-type Josephson junction in a narrow thin-film superconducting strip can change drastically the dependence of the junction critical current on the applied field, I-c(H). When the vortex is placed at certain discrete positions in the strip middle, the pattern I-c(H) has zero at H = 0 instead of the traditional maximum of '0-type' junctions. The number of these positions is equal to the number of vortices trapped at the same location. When the junction-vortex separation exceeds similar to W, the strip width, I-c(H) is no longer sensitive to the vortex presence. The same is true for any separation if the vortex approaches the strip edges. (C) 2014 Elsevier B.V. All rights reserved.

  7. Cerro Prieto cold water injection: effects on nearby production wells

    SciTech Connect (OSTI)

    Truesdell, A.H.; Lippmann, M.J.; De Leon, J.; Rodriguez, M.H.


    The liquid-dominated Cerro Prieto geothermal field of northern Baja California, Mexico has been under commercial exploitation since 1973. During the early years of operation, all waste brines were sent to an evaporation pond built west of the production area. In 1989, cooled pond brines began to be successfully injected into the reservoir along the western boundary of the geothermal system. The injection rate varied over the years, and is at present about 20% of the total fluid extracted. As expected under the continental desert conditions prevailing in the area, the temperature and salinity of the pond brines change with the seasons, being higher during the summer and lower during the winter. The chemistry of pond brines is also affected by precipitation of silica, oxidation of H{sub 2}S and reaction with airborne clays. Several production wells in the western part of the field (CP-I area) showed beneficial effects from injection. The chemical (chloride, isotopic) and physical (enthalpy, flow rate) changes observed in producers close to the injectors are reviewed. Some wells showed steam flow increases, in others steam flow decline rates flattened. Because of their higher density, injected brines migrated downward in the reservoir and showed up in deep wells.

  8. Supernova Discoveries from the Nearby Supernova Factory (SNfactory...

    Office of Scientific and Technical Information (OSTI)

    Host Website: Lawrence Berkeley National Laboratory (LBNL) Sponsoring Org: USDOE Office of Science (SC); Gordon and Betty Moore Foundation; National Science Foundation (NSF); Yale ...

  9. Geothermal energy: obstacles and uncertainties impede its widespread use

    SciTech Connect (OSTI)

    Staats E.B.


    A perspective on geothermal energy's development and potential and a discussion of Federal actions needed to help accelerate geothermal development and use are included. (MHR)

  10. NREL Overcomes Obstacles in Lignin Valorization (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available


    This NREL Highlight is being produced for the 2015 February Alliance S&T Board meeting, and describes research that shows lignin can be converted into renewable fuels, chemicals, and materials.

  11. A Delicate Universe: Compactification Obstacles to D-brane Inflation...

    Office of Scientific and Technical Information (OSTI)

    10.1103PhysRevLett.99.141601; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA) Country of Publication: United States Language: ...

  12. Microsoft Word - THE EFFECT OF OBSTACLE#4781.doc

    Open Energy Info (EERE)

    KHADEM 1 , J. BADGER*, S. M. ULLAH, S. K. ADITYA, H. R. GHOSH & M. HUSSAIN Renewable Energy Research Centre, University of Dhaka, Bangladesh, e-mail: RISO...

  13. NREL Overcomes Obstacles in Lignin Valorization (Fact Sheet)...

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

    ates), hydroxy acids, and fuel-range alkanes from lignin-derived streams. By coupling metabolic engineering of the biological funneling pathways to chemical catalysis, this...

  14. On a Highly Nonlinear Self-Obstacle Optimal Control Problem ...

    Office of Scientific and Technical Information (OSTI)

    ...ience+Business Media New York;; Country of input: International Atomic Energy Agency (IAEA) Country of Publication: United States Language: English ...

  15. DE-FC26-02NT41318 |

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

    Differential Soil Impedance Obstacle Detection DE-FC26-02NT41318 Goal: The goal of this project is to design, fabricate, and test a prototype sensor system for detecting obstacles in front of, or nearby the head of a horizontal directional drilling (HDD) rig. The sensor will be designed to be sensitive to metallic, plastic, or ceramic obstacles embedded in the soil. Background: The use of guided directional drilling for the installation of gas services and mains by the natural gas industry is

  16. Robotic Follow Algorithm

    Energy Science and Technology Software Center (OSTI)


    The Robotic Follow Algorithm enables allows any robotic vehicle to follow a moving target while reactively choosing a route around nearby obstacles. The robotic follow behavior can be used with different camera systems and can be used with thermal or visual tracking as well as other tracking methods such as radio frequency tags.

  17. Wind Energy Assessment Study for Nevada -- Tall Tower Deployment (Stone Cabin): 26 June 2005 - 31 December 2007

    SciTech Connect (OSTI)

    Koracin, D.; Reinhardt, R.; McCurdy, G.; Liddle, M.; McCord, T.; Vellore, R.; Minor, T.; Lyles, B.; Miller, D.; Ronchetti, L.


    The objective of this work effort was to characterize wind shear and turbulence for representative wind-developable areas in Nevada.

  18. Water supply and use in Deaf Smith, Swisher, and nearby counties in the Texas Panhandle

    SciTech Connect (OSTI)

    Not Available


    Irrigation for agriculture is the primary water use in the area of Deaf Smith and Swisher Counties, Texas, and the Ogallala Formation is the main water source. The availability of water in the 12-county area is projected to decrease markedly over the next 5 decades because of the steady depletion of ground water in recoverable storage. Water requirements in the 12-county area are projected to exceed available supplies from about 1990 through 2030. The shortage for the year 2030 is estimated to be approximately 4 million acre-feet under high-growth-rate conditions. Because of its semiarid climate, the area has little available surface water to augment the supply of the Ogallala Formation, which, despite its depletion, could be the principal source of water for the repository. There are, however, other potential sources of water: (1) Lake Mackenzie, on Tule Creek; (2) the Santa Rosa Formation, which underlies much of the Southern High Plains and locally yields moderate amounts of good-quality water; and (3) the Wolfcamp Series, which yields low amounts of highly saline water. The effluents of municipal wastewater treatment plants and municipal water systems may also be useful as supplements to the repository's primary water supply.

  19. A mid-infrared search for substellar companions of nearby planet-host stars

    SciTech Connect (OSTI)

    Hulsebus, A.; Marengo, M.; Carson, J.; Stapelfeldt, K.


    Determining the presence of widely separated substellar-mass companion is crucial to understand the dynamics of inner planets in extrasolar planetary systems (e.g., to explain their high mean eccentricity as inner planets are perturbed by the Kozai mechanism). We report the results of our Spitzer/Infrared Array Camera (IRAC) imaging search for widely separated (10''-25'') substellar-mass companions for 14 planet-host stars within 15 pc of the Sun. Using deep 3.6 and 4.5 μm observations in subarray mode, we found one object in the field of 47 UMa with [3.6]–[4.5] color similar to a T5 dwarf, which is, however, unlikely to share common proper motion with 47 UMa. We also found three objects with brown-dwarf-like [3.6]–[4.5] color limits in the fields of GJ 86, HD 160691, and GJ 581, as well as another in the field of HD 69830 for which we have excluded common proper motion. We provide model-based upper mass limits for unseen objects around all stars in our sample, with typical sensitivity to 10 M {sub J} objects from a projected separation of 50-300 AU from the parent star. We also discuss our data analysis methods for point-spread-function subtraction, image co-alignment, and artifact subtraction of IRAC subarray images.

  20. A tidal disruption event in a nearby galaxy hosting an intermediate mass black hole

    SciTech Connect (OSTI)

    Donato, D.; Troja, E.; Pursimo, T.; Cheung, C. C.; Kutyrev, A.; Landt, H.; Butler, N. R.


    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined by a factor of ?2300 over a time span of 6 yr, following a power-law decay with index ?2.44 0.40. The Chandra data alone vary by a factor of ?20. The spectrum is well fit by a blackbody with a constant temperature of kT ? 0.09 keV (?10{sup 6} K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1? level with the cluster (z = 0.062476). We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log (M {sub BH}/M {sub ?}) ? 5.5 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  1. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy...

    Office of Scientific and Technical Information (OSTI)


  2. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy...

    Office of Scientific and Technical Information (OSTI)

    Authors: Kelly, Patrick L. ; KIPAC, Menlo Park SLAC ; Hicken, Malcolm ; Harvard-Smithsonian Ctr. Astrophys. ; Burke, David L. ; KIPAC, Menlo Park SLAC ; Mandel, Kaisey S. ; ...

  3. The NuSTAR View of Nearby Compton-thick Active Galactic Nuclei...

    Office of Scientific and Technical Information (OSTI)

    Dept. ; Brandt, W.N. ; Pennsylvania U. Penn State U., University Park, IGC ; Brightman, M. ; Garching, Max Planck Inst., MPE Denmark, Tech. U. ; Christensen, F.E. ; Craig, W.W. ...


    SciTech Connect (OSTI)

    Wolleben, M.; Landecker, T. L.; Fletcher, A.; Carretti, E.; McClure-Griffiths, N.; Dickey, J. M.; Gaensler, B. M.; Haverkorn, M.; Reich, W.; Taylor, A. R.


    Rotation measures (RMs) of pulsars and extragalactic point sources have been known to reveal large-scale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the northern Galactic hemisphere. Through application of RM synthesis we achieve sensitive Faraday rotation maps with high angular resolution, capable of revealing fine-scale structures of {approx}1{sup 0} in the Faraday rotation sky. Our analysis suggests that the observed antisymmetry in the Faraday rotation sky at b>0{sup 0} is dominated by the magnetic field around a local H I bubble at a distance of 100 pc, and not by the magnetic field of the Galactic halo. We derive physical properties of the magnetic field of this shell, which we find to be 20-34 {mu}G strong. It is clear that the diffuse polarized radio emission contains important information about the local magneto-ionic medium, which cannot yet be derived from Faraday RMs of extragalactic sources or pulsars alone.


    SciTech Connect (OSTI)

    Yang, Huan; Wang, JunXian; Liu, Teng E-mail:


    In the center of active galactic nuclei (AGNs), the dusty torus absorbs the radiation from the central engine and reemits in mid-infrared (MIR). Observations have detected moderate anisotropy in the dust MIR emission, in the way that type 1 AGNs (type1s) are mildly brighter in MIR comparing with type 2 sources (type2s). However, type1s and type2s were found to follow statistically the same tight MIR-hard X-ray correlation, suggesting that the MIR emission is highly isotropic assuming that the hard X-ray radiation is inclination independent. We argue that this discrepancy could be solved considering that the hard X-ray emission in AGNs is also mildly anisotropic, as we recently discovered. To verify this diagram, we compare the subarcsecond 12 μm flux densities of type1s and type2s using the [O IV] λ25.89 μm emission line as an isotropic luminosity indicator. We find that on average type1s are brighter in nuclei 12 μm radiation by a factor of 2.6 ± 0.6 than type2s at given [O IV] λ25.89 μm luminosities, confirming the mild anisotropy of the nuclei 12 μm emission. We show that the anisotropy of the 12 μm emission we detected is in good agreement with radiative transfer models of clumpy tori. The fact that type1s and type2s follow the same tight MIR-hard X-ray correlation instead supports that both the MIR emission and hard X-ray emission in AGNs are mildly anisotropic.

  6. The NuSTAR View of Nearby Compton-thick Active Galactic Nuclei...

    Office of Scientific and Technical Information (OSTI)

    ; Alexander, D.M. ; Durham U. ; Ballantyne, D.R. ; Georgia Tech., Atlanta ; Bauer, F.E. ; Chile U., Catolica Space Sci. Inst., Boulder ; Boggs, S.E. ; UC, Berkeley, Space Sci. ...


    Office of Scientific and Technical Information (OSTI)

    2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (sup -1 per 2'' fiber) at 23 AB mag arcsecsup -2, which is typical...

  8. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  9. The impact of a filament eruption on nearby high-lying cool loops

    SciTech Connect (OSTI)

    Harra, L. K.; Matthews, S. A.; Long, D. M.; Doschek, G. A.; De Pontieu, B.


    The first spectroscopic observations of cool Mg II loops above the solar limb observed by NASA's Interface Region Imaging Spectrograph (IRIS) are presented. During the observation period, IRIS is pointed off-limb, allowing the observation of high-lying loops, which reach over 70 Mm in height. Low-lying cool loops were observed by the IRIS slit-jaw camera for the entire four-hour observing window. There is no evidence of a central reversal in the line profiles, and the Mg II h/k ratio is approximately two. The Mg II spectral lines show evidence of complex dynamics in the loops with Doppler velocities reaching 40 km s{sup 1}. The complex motions seen indicate the presence of multiple threads in the loops and separate blobs. Toward the end of the observing period, a filament eruption occurs that forms the core of a coronal mass ejection. As the filament erupts, it impacts these high-lying loops, temporarily impeding these complex flows, most likely due to compression. This causes the plasma motions in the loops to become blueshifted and then redshifted. The plasma motions are seen before the loops themselves start to oscillate as they reach equilibrium following the impact. The ratio of the Mg h/k lines also increases following the impact of the filament.

  10. Obstacles to the use of exterior fenestration and daylighting control systems in the US

    SciTech Connect (OSTI)

    Sweitzer, G.; Johnson, R.


    Exterior fenestration and daylighting control systems can provide excellent control of solar gain and glare and still be visually satisfying elements in the design of building envelopes. However, US building industry experience with exterior fenestration and daylighting control systems suggests that durability and proper function of these systems is often unsatisfactory. Yet in Western Europe, exterior systems are a proven, cost-effective, and aesthetically accepted fenestration design element. It is suggested that these contrasting operating experiences reflect differences in prevailing US/Western European approaches to building design, construction, and operation. Three representative US building case studies are examined, each describing the application of exterior fenestration/daylighting control components previously untested as a system, and some unsatisfactory consequences. Several changes that may assist in increasing the acceptance and success of these systems in the US building industry are suggested.

  11. Elimination of a spiral wave pinned at an obstacle by a train...

    Office of Scientific and Technical Information (OSTI)

    Kyoto 606-8501 (Japan) Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522 (Japan) Faculty of Life and Medical Sciences, Doshisha University, ...

  12. Proposed roadmap for overcoming legal and financial obstacles to carbon capture and sequestration

    SciTech Connect (OSTI)

    Jacobs, Wendy ); Chohen, Leah; Kostakidis-Lianos, Leah; Rundell, Sara )


    Many existing proposals either lack sufficient concreteness to make carbon capture and geological sequestration (CCGS) operational or fail to focus on a comprehensive, long term framework for its regulation, thus failing to account adequately for the urgency of the issue, the need to develop immediate experience with large scale demonstration projects, or the financial and other incentives required to launch early demonstration projects. We aim to help fill this void by proposing a roadmap to commercial deployment of CCGS in the United States.This roadmap focuses on the legal and financial incentives necessary for rapid demonstration of geological sequestration in the absence of national restrictions on CO2 emissions. It weaves together existing federal programs and financing opportunities into a set of recommendations for achieving commercial viability of geological sequestration.

  13. Biomass energy: State of the technology present obstacles and future potential

    SciTech Connect (OSTI)

    Dobson, L.


    The prevailing image of wood and waste burning as dirty and environmentally harmful is no longer valid. The use of biomass combustion for energy can solve many of our nation`s problems. Wood and other biomass residues that are now causing expensive disposal problems can be burned as cleanly and efficiently as natural gas, and at a fraction of the cost. New breakthroughs in integrated waste-to-energy systems, from fuel handling, combustion technology and control systems to heat transfer and power generation, have dramatically improved system costs, efficiencies, cleanliness of emissions, maintenance-free operation, and end-use applications. Increasing costs for fossil fuels and for waste disposal strict environmental regulations and changing political priorities have changed the economics and rules of the energy game. This report will describe the new rules, new playing fields and key players, in the hope that those who make our nation`s energy policy and those who play in the energy field will take biomass seriously and promote its use.

  14. X- and γ-ray pulsations of the nearby radio-faint PSR J1741–2054

    SciTech Connect (OSTI)

    Marelli, M.; Belfiore, A.; Caraveo, P.; De Luca, A.; Salvetti, D.; Saz Parkinson, P.; Sarazin, C.; Sivakoff, G. R.; Camilo, F.


    We report the results of a deep XMM-Newton observation of the radio-faint γ-ray pulsar J1741–2054 and its nebula together with the analysis of five years of Fermi Large Area Telescope (LAT) data. The X-ray spectrum of the pulsar is consistent with an absorbed power law plus a blackbody, originating at least partly from the neutron star cooling. The nebular emission is consistent with that of a synchrotron pulsar wind nebula, with hints of spatial spectral variation. We extended the available Fermi LAT ephemeris and folded the γ-ray and X-ray data. We detected X-ray pulsations from the neutron star: both the thermal and non-thermal components are ∼35%-40% pulsed, with phase-aligned maxima. A sinusoid fits the thermal-folded profile well. A 10 bin phase-resolved analysis of the X-ray emission shows softening of the non-thermal spectrum during the on-pulse phases. The radio, X-ray, and γ-ray light curves are single-peaked, not phase-aligned, with the X-ray peak trailing the γ-ray peak by more than half a rotation. Spectral considerations suggest that the most probable pulsar distance is in the 0.3-1.0 kpc range, in agreement with the radio dispersion measure.

  15. Color-magnitude distribution of face-on nearby galaxies in Sloan digital sky survey DR7

    SciTech Connect (OSTI)

    Jin, Shuo-Wen; Feng, Long-Long; Gu, Qiusheng; Huang, Song; Shi, Yong


    We have analyzed the distributions in the color-magnitude diagram (CMD) of a large sample of face-on galaxies to minimize the effect of dust extinctions on galaxy color. About 300,000 galaxies with log (a/b) < 0.2 and redshift z < 0.2 are selected from the Sloan Digital Sky Survey DR7 catalog. Two methods are employed to investigate the distributions of galaxies in the CMD, including one-dimensional (1D) Gaussian fitting to the distributions in individual magnitude bins and two-dimensional (2D) Gaussian mixture model (GMM) fitting to galaxies as a whole. We find that in the 1D fitting, two Gaussians are not enough to fit galaxies with the excess present between the blue cloud and the red sequence. The fitting to this excess defines the center of the green valley in the local universe to be (u – r){sub 0.1} = –0.121M {sub r,} 0{sub .1} – 0.061. The fraction of blue cloud and red sequence galaxies turns over around M {sub r,} {sub 0.1} ∼ –20.1 mag, corresponding to stellar mass of 3 × 10{sup 10} M {sub ☉}. For the 2D GMM fitting, a total of four Gaussians are required, one for the blue cloud, one for the red sequence, and the additional two for the green valley. The fact that two Gaussians are needed to describe the distributions of galaxies in the green valley is consistent with some models that argue for two different evolutionary paths from the blue cloud to the red sequence.


    SciTech Connect (OSTI)

    Looney, B.; Eddy-Dilek, C.


    Evaluation of disposal records, soil data, and spatial/temporal groundwater data from the Paducah Gaseous Diffusion Plant (PGDP) Solid Waste Management Unit (SWMU) 7 indicate that the peak contaminant concentrations measured in monitoring well (MW) 66 result from the influence of the regional PGDP NW Plume, and does not support the presence of significant vertical transport from local contaminant sources in SWMU 7. This updated evaluation supports the 2006 conceptualization which suggested the high and low concentrations in MW66 represent different flow conditions (i.e., local versus regional influences). Incorporation of the additional lines of evidence from data collected since 2006 provide the basis to link high contaminant concentrations in MW66 (peaks) to the regional 'Northwest Plume' and to the upgradient source, specifically, the C400 Building Area. The conceptual model was further refined to demonstrate that groundwater and the various contaminant plumes respond to complex site conditions in predictable ways. This type of conceptualization bounds the expected system behavior and supports development of environmental cleanup strategies, providing a basis to support decisions even if it is not feasible to completely characterize all of the 'complexities' present in the system. We recommend that the site carefully consider the potential impacts to groundwater and contaminant plume migration as they plan and implement onsite production operations, remediation efforts, and reconfiguration activities. For example, this conceptual model suggests that rerouting drainage water, constructing ponds or basin, reconfiguring cooling water systems, capping sites, decommissioning buildings, fixing (or not fixing) water leaks, and other similar actions will potentially have a 'direct' impact on the groundwater contaminant plumes. Our conclusion that the peak concentrations in MW66 are linked to the regional PGDP NW Plume does not imply that there TCE is not present in SWMU 7. The available soil and groundwater data indicate that the some of the waste disposed in this facility contacted and/or were contaminated by TCE. In our assessment, the relatively small amount of TCE associated with SWMU 7 is not contributing detectable TCE to the groundwater and does not represent a significant threat to the environment, particularly in an area where remediation and/or management of TCE in the NW plume will be required for an extended timeframe. If determined to be necessary by the PGDP team and regulators, additional TCE characterization or cleanup activities could be performed. Consistent with the limited quantity of TCE in SWMU 7, we identify a range of low cost approaches for such activities (e.g., soil gas surveys for characterization or SVE for remediation). We hope that this information is useful to the Paducah team and to their regulators and stakeholders to develop a robust environmental management path to address the groundwater and soil contamination associated with the burial ground areas.


    SciTech Connect (OSTI)

    Stocke, John T.; Keeney, Brian A.; Danforth, Charles W.; Shull, J. Michael; Froning, Cynthia S.; Green, James C.; Penton, Steven V. [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado, 389 UCB, Boulder, CO 80309 (United States)] [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Savage, Blair D., E-mail: [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)


    The circumgalactic medium (CGM) of late-type galaxies is characterized using UV spectroscopy of 11 targeted QSO/galaxy pairs at z {<=} 0.02 with the Hubble Space Telescope Cosmic Origins Spectrograph (COS) and {approx}60 serendipitous absorber/galaxy pairs at z {<=} 0.2 with the Space Telescope Imaging Spectrograph. CGM warm cloud properties are derived, including volume filling factors of 3%-5%, cloud sizes of 0.1-30 kpc, masses of 10-10{sup 8} M {sub Sun }, and metallicities of {approx}0.1-1 Z {sub Sun }. Almost all warm CGM clouds within 0.5 R {sub vir} are metal-bearing and many have velocities consistent with being bound, 'galactic fountain' clouds. For galaxies with L {approx}> 0.1 L*, the total mass in these warm CGM clouds approaches 10{sup 10} M {sub Sun }, {approx}10%-15% of the total baryons in massive spirals and comparable to the baryons in their parent galaxy disks. This leaves {approx}> 50% of massive spiral-galaxy baryons 'missing'. Dwarfs (<0.1 L*) have smaller area covering factors and warm CGM masses ({<=}5% baryon fraction), suggesting that many of their warm clouds escape. Constant warm cloud internal pressures as a function of impact parameter (P/k {approx} 10 cm{sup -3} K) support the inference that previous COS detections of broad, shallow O VI and Ly{alpha} absorptions are of an extensive ({approx}400-600 kpc), hot (T Almost-Equal-To 10{sup 6} K), intra-cloud gas which is very massive ({>=}10{sup 11} M {sub Sun }). While the warm CGM clouds cannot account for all the 'missing baryons' in spirals, the hot intra-group gas can, and could account for {approx}20% of the cosmic baryon census at z {approx} 0 if this hot gas is ubiquitous among spiral groups.


    SciTech Connect (OSTI)

    Helou, George; Surace, Jason; Kasliwal, Mansi M.; Ofek, Eran O.; Arcavi, Iair; Gal-Yam, Avishay


    We present Spitzer observations at 3.6 and 4.5 μm of the supernova SN 2011dh (PTF 11eon) in M51 from 18 days to 625 days after explosion. The mid-infrared emission peaks at 24 days after explosion at a few ×10{sup 7} L {sub ☉}, and decays more slowly than the visible-light bolometric luminosity. The infrared color temperature cools for the first 90 days and then is constant. Simple numerical models of a thermal echo can qualitatively reproduce the early behavior. At late times, the mid-IR light curve cannot be explained by a simple thermal echo model, suggesting additional dust heating or line emission mechanisms. We also propose that thermal echoes can serve as effective probes to uncover supernovae in heavily obscured environments, and speculate that under the right conditions, integrating the early epoch of the mid-infrared light curve may constrain the total energy in the shock breakout flash.

  19. Structural foam-core panels in Northwest HUD-code manufactured housing: A preliminary assessment of opportunities and obstacles

    SciTech Connect (OSTI)

    Durfee, D.L.; Lee, A.D.; Onisko, S.A.


    This investigation of structural foam-core panels (foam panels) in manufactured housing was initiated during the Super Good Cents (SGC) program. The SGC program limited allowable glazing area because of the relatively high thermal losses associated with most windows. Due to their superior thermal performance, foam panels appeared to be a viable option to allow increased glazing area without compromising the thermal integrity of the wall. With the inception of the Manufactured-Housing Acquisition Program (MAP), however, the focus of this study has shifted. MAP permits unlimited glazing area if expensive, super-efficient, vinyl-framed, argon-gas-filled, low-emissivity coated windows are installed. Although MAP permits unlimited glazing area, a foam panel wall could allow the use of less expensive windows, larger window area, or less insulation and still provide the required thermal performance for the building. Bonneville contracted with the Pacific Northwest Laboratory (PNL) to investigate the feasibility of using foam panels in HUD-code manufactured housing. This study presents the results from a product and literature search. The potential barriers and benefits to the use of foam panels are determined from a regional survey of the HUD-code manufacturers and foam panel producers.

  20. EIS-0285-SA-38: Supplement Analysis | Department of Energy

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

    BPA plans to conduct vegetation control with the goal of removing tall growing vegetation ... resprouting noxious weeds and tall-growing species along access roads and tower sites. ...

  1. (DOE/EIS-0285/SA-04): Supplement Analysis for the Transmission...

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

    needed: The project involves cutting all tall growing trees and brush within BPA's ... Vegetation to be controlled: Juniper trees are the only tall growing tree species within ...

  2. Constraining dark matter halo profiles and galaxy formation models using spiral arm morphology. II. Dark and stellar mass concentrations for 13 nearby face-on galaxies

    SciTech Connect (OSTI)

    Seigar, Marc S. [Department of Physics, University of Minnesota Duluth, 1023 University Drive, MWAH 371, Duluth, MN 55812-3009 (United States); Davis, Benjamin L.; Berrier, Joel; Kennefick, Daniel [Arkansas Center for Space and Planetary Sciences, 202 Field House, University of Arkansas, Fayetteville, AR 72701 (United States)


    We investigate the use of spiral arm pitch angles as a probe of disk galaxy mass profiles. We confirm our previous result that spiral arm pitch angles (P) are well correlated with the rate of shear (S) in disk galaxy rotation curves. We use this correlation to argue that imaging data alone can provide a powerful probe of galactic mass distributions out to large look-back times. We then use a sample of 13 galaxies, with Spitzer 3.6 ?m imaging data and observed H? rotation curves, to demonstrate how an inferred shear rate coupled with a bulge-disk decomposition model and a Tully-Fisher-derived velocity normalization can be used to place constraints on a galaxy's baryon fraction and dark matter halo profile. Finally, we show that there appears to be a trend (albeit a weak correlation) between spiral arm pitch angle and halo concentration. We discuss implications for the suggested link between supermassive black hole (SMBH) mass and dark halo concentration, using pitch angle as a proxy for SMBH mass.

  3. Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Application

    SciTech Connect (OSTI)

    Tao, Greg, G.; Virkar, Anil, V.; Bandopadhyay, Sukumar; Thangamani, Nithyanantham; Anderson, Harlan, U.; Brow, Richard, K.


    Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode, respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and then separated by condensation of the steam to produce pure hydrogen. The rationale was that in such an approach fuel provides a chemical potential replacing the external power conventionally used to drive electrolysis cells (i.e. solid oxide electrolysis cells). A SOFC is similar to the SOFEC by replacing cathode steam with air for power generation. To fulfill the cogeneration objective, a hybrid module comprising reversible SOFEC stacks and SOFC stacks was designed that planar SOFECs and SOFCs were manifolded in such a way that the anodes of both the SOFCs and the SOFECs were fed the same fuel, (i.e. natural gas or coal-derived fuel). Hydrogen was produced by SOFECs and electricity was generated by SOFCs within the same hybrid system. A stand-alone 5 kW system comprising three SOFEC-SOFC hybrid modules and three dedicated SOFC stacks, balance-of-plant components (including a tailgas-fired steam generator and tailgas-fired process heaters), and electronic controls was designed, though an overall integrated system assembly was not completed because of limited resources. An inexpensive metallic interconnects fabrication process was developed in-house. BOP components were fabricated and evaluated under the forecasted operating conditions. Proof-of-concept demonstration of cogenerating hydrogen and electricity was performed, and demonstrated SOFEC operational stability over 360 hours with no significant degradation. Cost analysis was performed for providing an economic assessment of the cost of hydrogen production using the targeted hybrid technology, and for guiding future research and development.

  4. Structure of the red fluorescent protein from a lancelet (Branchiostoma lanceolatum): a novel GYG chromophore covalently bound to a nearby tyrosine

    SciTech Connect (OSTI)

    Pletnev, Vladimir Z. Pletneva, Nadya V.; Lukyanov, Konstantin A.; Souslova, Ekaterina A.; Fradkov, Arkady F.; Chudakov, Dmitry M.; Chepurnykh, Tatyana; Yampolsky, Ilia V.; Wlodawer, Alexander; Dauter, Zbigniew; Pletnev, Sergei


    The crystal structure of the novel red emitting fluorescent protein from lancelet Branchiostoma lanceolatum (Chordata) revealed an unusual five residues cyclic unit comprising Gly58-Tyr59-Gly60 chromophore, the following Phe61 and Tyr62 covalently bound to chromophore Tyr59. A key property of proteins of the green fluorescent protein (GFP) family is their ability to form a chromophore group by post-translational modifications of internal amino acids, e.g. Ser65-Tyr66-Gly67 in GFP from the jellyfish Aequorea victoria (Cnidaria). Numerous structural studies have demonstrated that the green GFP-like chromophore represents the ‘core’ structure, which can be extended in red-shifted proteins owing to modifications of the protein backbone at the first chromophore-forming position. Here, the three-dimensional structures of green laGFP (λ{sub ex}/λ{sub em} = 502/511 nm) and red laRFP (λ{sub ex}/λ{sub em} ≃ 521/592 nm), which are fluorescent proteins (FPs) from the lancelet Branchiostoma lanceolatum (Chordata), were determined together with the structure of a red variant laRFP-ΔS83 (deletion of Ser83) with improved folding. Lancelet FPs are evolutionarily distant and share only ∼20% sequence identity with cnidarian FPs, which have been extensively characterized and widely used as genetically encoded probes. The structure of red-emitting laRFP revealed three exceptional features that have not been observed in wild-type fluorescent proteins from Cnidaria reported to date: (i) an unusual chromophore-forming sequence Gly58-Tyr59-Gly60, (ii) the presence of Gln211 at the position of the conserved catalytic Glu (Glu222 in Aequorea GFP), which proved to be crucial for chromophore formation, and (iii) the absence of modifications typical of known red chromophores and the presence of an extremely unusual covalent bond between the Tyr59 C{sup β} atom and the hydroxyl of the proximal Tyr62. The impact of this covalent bond on the red emission and the large Stokes shift (∼70 nm) of laRFP was verified by extensive structure-based site-directed mutagenesis.

  5. Spatially resolved chemistry in nearby galaxies. III. Dense molecular gas in the inner disk of the LIRG IRAS 04296+2923

    SciTech Connect (OSTI)

    Meier, David S.; Turner, Jean L.; Beck, Sara C. E-mail:


    We present a survey of 3 mm molecular lines in IRAS 04296+2923, one of the brightest known molecular-line emitting galaxies, and one of the closest luminous infrared galaxies (LIRGs). Data are from the Owens Valley and CARMA millimeter interferometers. Species detected at ≲ 4'' resolution include C{sup 18}O, HCN, HCO{sup +}, HNC, CN, CH{sub 3}OH, and, tentatively, HNCO. Along with existing CO, {sup 13}CO, and radio continuum data, these lines constrain the chemical properties of the inner disk. Dense molecular gas in the nucleus fuels a star formation rate ≳10 M {sub ☉} yr{sup –1} and is traced by lines of HCN, HCO{sup +}, HNC, and CN. A correlation between HCN and star formation rate is observed on sub-kiloparsec scales, consistent with global relations. Toward the nucleus, CN abundances are similar to those of HCN, indicating emission comes from a collection (∼40-50) of moderate visual extinction, photon-dominated-region clouds. The CO isotopic line ratios are unusual: CO(1-0)/{sup 13}CO(1-0) and CO(1-0)/C{sup 18}O(1-0) line ratios are large toward the starburst, as is commonly observed in LIRGs, but farther out in the disk these ratios are remarkably low (≲ 3). {sup 13}CO/C{sup 18}O abundance ratios are lower than in Galactic clouds, possibly because the C{sup 18}O is enriched by massive star ejecta from the starburst. {sup 13}CO is underabundant relative to CO. Extended emission from CH{sub 3}OH indicates that dynamical shocks pervade both the nucleus and the inner disk. The unusual CO isotopologue ratios, the CO/HCN intensity ratio versus L {sub IR}, the HCN/CN abundance ratio, and the gas consumption time versus inflow rate all indicate that the starburst in IRAS 04296+2923 is in an early stage of development.


    SciTech Connect (OSTI)

    Davidge, T. J.


    Long slit spectra recorded with the Gemini Multi-Object Spectrograph on Gemini South are used to examine the star-forming history (SFH) of the lenticular galaxy NGC5102. Structural and supplemental photometric information are obtained from archival Spitzer [3.6] images. Absorption features at blue and visible wavelengths are traced out along the minor axis to galactocentric radii ?60 arcsec (?0.9 kpc), sampling the nucleus, bulge, and disk components. Comparisons with model spectra point to luminosity-weighted metallicities that are consistent with the colors of resolved red giant branch stars in the disk. The nucleus has a luminosity-weighted age at visible wavelengths of ?1{sub ?0.1}{sup +0.2}Gyr, and the integrated light is dominated by stars that formed over a time period of only a few hundred Myr. For comparison, the luminosity-weighted ages of the bulge and disk are ?2{sub ?0.2}{sup +0.5}Gyr and 10{sub ?2}{sup +2}Gyr, respectively. The g' [3.6] colors of the nucleus and bulge are consistent with the spectroscopically based ages. In contrast to the nucleus, models that assume star-forming activity spanning many Gyr provide a better match to the spectra of the bulge and disk than simple stellar population models. Isophotes in the bulge have a disky shape, hinting that the bulge was assembled from material with significant rotational support. The SFHs of the bulge and disk are consistent with the bulge forming from the collapse of a long-lived bar, rather than from the collapse of a transient structure that formed as the result of a tidal interaction. It is thus suggested that the progenitor of NGC5102 was a barred disk galaxy that morphed into a lenticular galaxy through the buckling of its bar.

  7. Executive summary: legal obstacles and incentives to the development of small scale hydroelectric potential in the seven mid-western states

    SciTech Connect (OSTI)



    The relationship of Federal law and regulation to state law and regulation of small-scale hydroelectric facilities is described. Important features of the constitutional law, statutory law, case law, and regulations of each of the 7 mid-western states (Illinois, Indiana, Kentucky, Michigan, Ohio, West Virginia, and Wisconsin) are highlighted. The introductory section examines the dual regulatory system from the standpoint of the appropriate legal doctrine, i.e., the law of pre-emption, and the application of this law to the case of hydroelectric development and regulation of water resources. A state-by-state synopsis of these important provisions of the laws of the states that have a bearing on small-scale hydroelectric development is presented.

  8. Case studies of the legal and institutional obstacles and incentives to the development of small-scale hydroelectric power: South Columbia Basin Irrigation District, Pasco, Washington

    SciTech Connect (OSTI)

    Schwartz, L.


    The case study concerns two modern human uses of the Columbia River - irrigation aimed at agricultural land reclamation and hydroelectric power. The Grand Coulee Dam has become synonomous with large-scale generation of hydroelectric power providing the Pacific Northwest with some of the least-expensive electricity in the United States. The Columbia Basin Project has created a half-million acres of farmland in Washington out of a spectacular and vast desert. The South Columbia River Basin Irrigation District is seeking to harness the energy present in the water which already runs through its canals, drains, and wasteways. The South District's development strategy is aimed toward reducing the costs its farmers pay for irrigation and raising the capital required to serve the remaining 550,000 acres originally planned as part of the Columbia Basin Project. The economic, institutional, and regulatory problems of harnessing the energy at site PEC 22.7, one of six sites proposed for development, are examined in this case study.

  9. Paducah Demolition Debris Shipped for Disposition | Department...

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

    ... about 1.5 million cubic feet, the volume of a football field roughly three stories tall. ... about 1.5 million cubic feet, the volume of a football field roughly three stories tall. ...

  10. DOE Issues RFI and Industry Day Announcement on Optimal Design...

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

    ... It is 375 feet in diameter and 43 feet tall, while units 2, 3 and 5 are 150 feet in diameter and 22 feet tall. SDU-6 and future units will hold approximately 30 million gallons of ...

  11. Workers Will Clean Up Groundwater Contamination Source With Deep...

    Broader source: (indexed) [DOE]

    150-foot-tall crane turns an eight-foot-diameter auger performing deep-soil mixing at the ... A 150-foot-tall crane turns an eight-foot-diameter auger performing deep-soil mixing at ...

  12. Numerical simulation of solar heat absorption within indoor space by means of composite grid method

    SciTech Connect (OSTI)

    Omori, Toshiaki; Murakami, Shuzo; Kato, Shinsuke


    This paper describes the method for numerical simulation of solar radiation entering indoor spaces through fenestration. The proposed method can systematically deal with the interception of sunlight by buildings in the outdoor space and obstacles in the indoor space by tracing a large number of particles directed toward the sun. Configuration factors from the fenestration to the sky are also three-dimensionally treated by accounting for outdoor geometries. Distribution of the solar heat absorption in the indoor space is calculated by assuming radiation equilibrium. After the solar heat absorption analysis is carried out, heat transfer analysis in the space is conducted taking account of longwave radiation, convective heat transfer, thermal conduction, and cooling/heating by air conditioning. Then, the indoor thermal environment is evaluated using the resulting temperature distribution of air and indoor surfaces. To evaluate the applicability of these procedures, the thermal environment in a model hall with large glass windows and an overhang is predicted. The analyzed hall is assumed to be located near a tall building.


    SciTech Connect (OSTI)

    Kane, R J; Baluyot, E V


    The iButton is a 'one-wire', temperature sensor and data logger in a short metal cylinder package 17 mm in diameter and 6 mm tall. The device is designed to be attached to a surface and acquire temperature samples over time periods as short as 1 second to as long as 300 minutes. Both 8-bit and 16-bit samples are available with 8kB of memory available. Lifetime is limited to an internal battery that cannot be replaced or recharged. The RF test interest originated with the concern that the data logger could inadvertently record electrical emanations from other nearby equipment. The normal operation of the data logger does not support high speed sampling but the control interface will operate at either 15.4 kbps or 125 kbps. There were no observable effects in the operation of the module or in the data that could be attributed to the use of RF energy. They made the assumption that these devices would potentially show RF sensitivity in any of the registers and in the data memory equally, therefore gross changes in the data might show RF susceptibility. No such sensitivity was observed. Because significant power levels were used for these tests they can extrapolate downward in power to state that no RF susceptibility would occur at lower power levels given the same configurations.


    SciTech Connect (OSTI)

    Watson, D.; French, J.; Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Castro Ceron, J. M.; Christensen, L.; O'Halloran, B.; Michalowski, M.; Gordon, K. D.; Covino, S.


    Gamma-ray burst (GRB) host galaxies have been studied extensively in optical photometry and spectroscopy. Here we present the first mid-infrared spectrum of a GRB host, HG 031203. It is one of the nearest GRB hosts at z = 0.1055, allowing both low- and high-resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS). Medium-resolution UV to K-band spectroscopy with the X-shooter spectrograph on the Very Large Telescope is also presented, along with Spitzer IRAC and MIPS photometry, as well as radio and submillimeter observations. These data allow us to construct a UV to radio spectral energy distribution with almost complete spectroscopic coverage from 0.3 to 35 {mu}m of a GRB host galaxy for the first time, potentially valuable as a template for future model comparisons. The IRS spectra show strong, high-ionization fine structure line emission indicative of a hard radiation field in the galaxy-in particular the [S IV]/[S III] and [Ne III]/[Ne II] ratios-suggestive of strong ongoing star formation and a very young stellar population. The absence of any polycyclic aromatic hydrocarbon emission supports these conclusions, as does the probable hot peak dust temperature, making HG 031203 similar to the prototypical blue compact dwarf galaxy (BCD), II Zw 40. The selection of HG 031203 via the presence of a GRB suggests that it might be a useful analog of very young star-forming galaxies in the early universe, and hints that local BCDs may be used as more reliable analogs of star formation in the early universe than typical local starbursts. We look at the current debate on the ages of the dominant stellar populations in z {approx} 7 and z {approx} 8 galaxies in this context. The nebular line emission is so strong in HG 031203 that at z {approx} 7, it can reproduce the spectral energy distributions of z-band dropout galaxies with elevated IRAC 3.6 and 4.5 {mu}m fluxes without the need to invoke a 4000 A break. Indeed, photometry of HG 031203 shows elevation of the broadband V-magnitude at a level similar to the IRAC elevation in stacked z-band dropouts, solely due to its strong [O III] line emission.

  15. Safety Evaluation Report: Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Applications, Materials and Systems Research, Inc. (MSRI), Salt Lake City, UT, February 17, 2009

    SciTech Connect (OSTI)

    Barilo, Nick F.; Frikken, Don; Skolnik, Edward G.; Weiner, Steven C.


    Following a telephone interview with Materials and Systems Research, Inc. (MSRI) by members of the Hydrogen Safety Panel on December 4, 2008, a safety review team was dispatched to Salt Lake City, UT to perform a site-visit review. The major topic of concern was the presence of a hydrogen storage and dispensing shed on the MSRI premises close to both its own laboratory/office building and to the adjoining property. The metal shed contains 36 cylinders (two 18-cylinder "pods") of hydrogen all connected to a common manifold and used to supply hydrogen to a U.S. Department of Energy (DOE) fuel cell project plus several other projects using an entire pod as a common supply. In busy times, MSRI uses and replaces one pod per week. As a result of the site visit, the safety review team has raised some concern with the shed’s location, design, use, and safety features as well as other components of the facility, including the laboratory area.

  16. K-25 Gaseous Diffusion Process Building | Department of Energy

    Broader source: (indexed) [DOE]

    other two being electromagnetic separation and liquid thermal diffusion. The S-50 liquid thermal diffusion plant, using convection to separate the isotopes in thousands of tall...

  17. I Laser Engineered Net Shaping

    Office of Scientific and Technical Information (OSTI)

    ... Of course, gun drilling and other special machining processes can achieve higher aspect ratios.) Tall thin- walled parts, the thickness of one laser pass, are built rapidly using ...

  18. Iowa's 5th congressional district: Energy Resources | Open Energy...

    Open Energy Info (EERE)

    County Corn Processors Siouxland Energy and Livestock Cooperative SELC Southern Iowa Bio Energy Soy Solutions Tall Corn Ethanol LLC West Central Biodiesel Investors LLC West...

  19. PowerPoint Presentation

    Office of Environmental Management (EM)

    ... Configuration Stainless Steel Frit * Approximately 6 grams total * 10 Pellets - Right cylinder pellets - 6 mm diameter x 4 mm tall * Stacked configuration Effect of H 2 ...

  20. Nanoscale Chemical Imaging of a Working Catalyst

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

    interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even...

  1. A I K E N

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

    communications tower. The dan- ger is from more than just strong wind, but also the corrosion of underground anchors that help support these tall structures. Anchors can become...

  2. GettingStarted_Master_2016-1

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

    ... Single chip 81 inc hes tall 10 Front-end nodes - dedicated for user's to login, ... - perform partitioning, monitoring, synchronization and other system management services. ...

  3. Southwest Plume Cleanup at Paducah Site to Start by Summer 2013...

    Broader source: (indexed) [DOE]

    ... Paducah Site Undergoing Steady Groundwater Cleanup with Variety of Methods Paducah Gaseous Diffusion Plant - GW OU Southwest Plume A 150-foot-tall crane turns an ...

  4. CO2 Capture by Absorption with Potassium Carbonate (Technical...

    Office of Scientific and Technical Information (OSTI)

    Stripper modeling has demonstrated that vacuum strippers will be more energy efficient if constructed short and fat rather than tall and skinny. The matrix stripper has been ...

  5. Press Pass - Press Releases

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

    DiversityWilderness. Since the Lab's inception, Fermilab has maintained a strong dedication to the environment. Environmental specialists have been restoring native tall-grass...

  6. Winnebago Resource Study. Cooperative Research and Development Final Report, CRADA Number CRD-09-329

    SciTech Connect (OSTI)

    Jimenez, A.; Robichaud, R.


    Since 2005 the NREL Native American Tall Tower Loan program has assisted Native American tribes to assess their wind resource by lending tall (30m - 50m) anemometer. This program has allowed tribes a lower risk way to gather financeable wind data for potential utility scale wind energy projects. These projects offer Tribes a significant economic development opportunity.

  7. Field Trip to EM’s Idaho Treatment Facility is Students’ High Point of Class

    Broader source: [DOE]

    IDAHO FALLS, Idaho – For graduate students in Dr. Mary Lou Dunzik-Gougar’s Idaho State University (ISU) radioactive waste management class, waste treatment takes on a new meaning when watching the Supercompactor transform a 725-pound, 35-inch-tall, 55-gallon drum into what looks like a 7-inch-tall, 2-foot-diameter hockey puck.

  8. Modeling needs for very large systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.


    Most system performance models assume a point measurement for irradiance and that, except for the impact of shading from nearby obstacles, incident irradiance is uniform across the array. Module temperature is also assumed to be uniform across the array. For small arrays and hourly-averaged simulations, this may be a reasonable assumption. Stein is conducting research to characterize variability in large systems and to develop models that can better accommodate large system factors. In large, multi-MW arrays, passing clouds may block sunlight from a portion of the array but never affect another portion. Figure 22 shows that two irradiance measurements at opposite ends of a multi-MW PV plant appear to have similar irradiance (left), but in fact the irradiance is not always the same (right). Module temperature may also vary across the array, with modules on the edges being cooler because they have greater wind exposure. Large arrays will also have long wire runs and will be subject to associated losses. Soiling patterns may also vary, with modules closer to the source of soiling, such as an agricultural field, receiving more dust load. One of the primary concerns associated with this effort is how to work with integrators to gain access to better and more comprehensive data for model development and validation.

  9. Mitigation of Hexavalent Chromium in Storm Water Resulting from Demolition of Large Concrete Structure at the East Tennessee Technology Park - 12286

    SciTech Connect (OSTI)

    Britto, Ronnie; Brown, Bridget; Hale, Timothy B.; Hensley, Janice L.; Johnson, Robert T.; Patel, Madhu; Emery, Jerry A.; Gaston, Clyde; Queen, David C.


    American Recovery and Reinvestment Act (ARRA) funding was provided to supplement the environmental management program at several DOE sites, including the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Demolition of the ETTP K-33 Building, the largest building to be demolished to date in Oak Ridge, was awarded to LSRS in FY-2010 under the ARRA program. The K-33 building was an 82 foot tall 2-story structure covering approximately 32 acres. Once this massive building was brought down to the ground, the debris was segregated and consolidated into piles of concrete rubble and steel across the remaining pad. The process of demolishing the building, tracking across concrete debris with heavy equipment, and stockpiling the concrete rubble caused it to become pulverized. During and after storm events, hexavalent chromium leached from the residual cement present in the large quantities of concrete. Storm water control measures were present to preclude migration of contaminants off-site, but these control measures were not designed to control hexavalent chromium dissolved in storm water from reaching nearby receiving water. The following was implemented to mitigate hexavalent chromium in storm water: - Steel wool was distributed around K-33 site catch basins and in water pools as an initial step in addressing hexavalent chromium. - Since the piles of concrete were too massive and unsafe to tarp, they were placed into windrows in an effort to reduce total surface area. - A Hach colorimetric field meter was acquired by the K-33 project to provide realtime results of hexavalent chromium in site surface water. - Three hexavalent chromium treatment systems were installed at three separate catch basins that receive integrated storm water flow from the K-33 site. Sodium bisulfite is being used as a reducing agent for the immobilization of hexavalent chromium while also assisting in lowering pH. Concentrations initially were 310 - 474 ppb of hexavalent chromium in

  10. Fermilab | Newsroom | Press Releases | March 28, 2013: NOvA neutrino...

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

    to construct the detector. The active section of the detector, under construction in Ash River, Minn., is about 12 feet long, 15 feet wide and 20 feet tall. The full detector...

  11. Fermilab | Newsroom | Press Releases | March 2013: NOvA Photos

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

    NOvA collaboration. Med Res | Hi Res The NOvA detector, currently under construction in Ash River, Minn., stands about 50 feet tall and 50 feet wide. The completed detector will...

  12. Fermilab | Newsroom | Press Releases | February 2014: NOvA Images

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

    NOvA collaboration Med Res | Hi Res The NOvA detector, currently under construction in Ash River, Minn., stands about 50 feet tall and 50 feet wide. The completed detector will...

  13. First U.S. Grid-Connected Offshore Wind Turbine Installed Off...

    Broader source: (indexed) [DOE]

    A 65-foot tall, 20-kilowatt wind turbine with a white rotor and a yellow tower on a ... Academy and Cianbro to launch a deepwater offshore floating wind turbine near Bangor. ...

  14. Press Pass - Press Releases

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

    section, which contains the detector's solenoid magnet, weighs as much as five jumbo jets and is 16 meters tall, 17 meters wide and 13 meters long. Its descent is expected to...

  15. Grouting at the Idaho National Laboratory Tank Farm Facility...

    Office of Environmental Management (EM)

    Small Tank Farm Facility * A system of 11 underground, 300,000-gallon stainless steel tanks - Tanks are fifty feet in diameter and twenty-five feet tall - Eight tanks have...

  16. University of Minnesota and the Department of Energy Celebrate...

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

    This is an excerpt from the Fourth Quarter 2011 edition of the Wind Program R&D ... Liberty wind turbine and a 426-foot-tall meteorological tower will enable industry ...

  17. DOE Zero Energy Ready Home National Program Requirements

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

    ... Location does not have significant natural shading (e.g., trees, tall buildings on the south-facing roof). d. Home as designed has adequate free roof area within +- 45 of true ...

  18. From: Deborah Stallbaumer To: Congestion Study Comments Subject...

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

    Landowners would be able to keep their land free from the tall, unsightly, and dangerous transmission towers, and the recipients of the power would benefit from a ready supply of ...

  19. CX-100262 Categorical Exclusion Determination | Department of...

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

    pole, 7 foot tall chain link security fence, motion sensor lighting and an 8 foot wide access road that would be built within the security fence for maintenance access to panels. ...

  20. HIA 2015 DOE Zero Energy Ready Home Case Study: BrightLeaf Homes...

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

    ... 8-inch poured concrete basement foundation wall, with 4 feet of wall below grade and 4 feet above to allow for significant natural light through the 36-inch-tall basement windows. ...

  1. CX-100475 Categorical Exclusion Determination | Department of...

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

    The EV charging station would be approximately 1'-4' by 2'-4' wide by 5' - 6' tall. The charging station would be located in the existing parking lot of the Lady Bird Park, a State ...

  2. EIS-0285-SA-140: Supplement Analysis | Department of Energy

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

    BPA plans to conduct vegetation control with the goal of removing tall growing vegetation that is currently or will soon be a hazard to the transmission line. BPA's overall goal is ...

  3. New Report Shows Domestic Offshore Wind Industry Potential, 21...

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

    Continuing to increase in size, the average offshore wind turbine installed in 2014 had a 377-foot-diameter rotor on a 279-foot-tall tower. The average capacity of offshore wind ...


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

    ... would run underground 850 feet to the northwe t adjacent to the service road , and then daylight to cross the river in a 570 foot span between two 70 to 75 foot tall steel pole . ...

  5. Drought-induced tree mortality accelerating in forests

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

    that describes the flow of liquid through a porous medium, which is how trees take in water. They found that tall plants with low hydraulic conductance and high leaf area are...

  6. EIS-0285-SA-111: Supplement Analysis | Department of Energy

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

    that will grow tall will be selectively eliminated before it reaches a height or density to begin competing with low-growing species. Cut-stump or follow- up herbicide...

  7. EIS-0285-SA-109: Supplement Analysis | Department of Energy

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

    that will grow tall will be selectively eliminated before it reaches a height or density to begin competing with low-growing species. Cut-stump or follow- up herbicide...

  8. RAPID/Roadmap/6-ID-a | Open Energy Information

    Open Energy Info (EERE)

    load A load is overlegal if the load is: width over 8'6"; Over 14' tall; Truck and trailer combined are over 75' long; or The load weighs over 80,000 pounds. 6-ID-a.2 - Meet...

  9. Deactivation Project Commences While Cleanup Continues at Paducah...

    Energy Savers [EERE]

    ... Paducah Site Undergoing Steady Groundwater Cleanup with Variety of Methods A 150-foot-tall crane turns an eight-foot-diameter auger performing deep-soil mixing at the Paducah ...

  10. NREL-Wind Resource Assessment Handbook | Open Energy Information

    Open Energy Info (EERE)

    or more measurement sites are located. The handbook's scope encompasses state-of-the-art measurement and analysis techniques at multiple heights on tall towers (e.g., 50 m) for a...

  11. Hanford Blog Archive - Hanford Site

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

    dedicated at Hanford March 17, 2011 GRAPHIC: Turnover of WTP facilities to operations, color-coded by year. March 04, 2011 VIDEO: Explosive demolition takes down two 250-foot tall...

  12. Project Management Institute Highlights Savannah River Nuclear Solutions in

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

    Publication | Department of Energy Project Management Institute Highlights Savannah River Nuclear Solutions in Publication Project Management Institute Highlights Savannah River Nuclear Solutions in Publication February 6, 2014 - 12:00pm Addthis American Recovery and Reinvestment Act workers at the Savannah River Site imploded the 455-foot-tall K Reactor Cooling Tower in May 2010. American Recovery and Reinvestment Act workers at the Savannah River Site imploded the 455-foot-tall K Reactor

  13. 'Recycling' Grid Energy with Flywheel Technology | Department of Energy

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

    'Recycling' Grid Energy with Flywheel Technology 'Recycling' Grid Energy with Flywheel Technology September 30, 2010 - 5:03pm Addthis Seven-foot tall cylinders equipped with flywheel technology (shown above) will make up Beacon Power’s energy storage plant in Stephentown, N.Y. The company received a $43 million loan guarantee from the Energy Department to build the plant. | Photo courtesy of Beacon Power Corporation Seven-foot tall cylinders equipped with flywheel technology (shown above)

  14. Wall-Friction Support of Vertical Loads in Submerged Sand and Gravel Columns

    SciTech Connect (OSTI)

    Walton, O. R.; Vollmer, H. J.; Hepa, V. S.


    Laboratory studies of the ‘floor-loads’ under submerged vertical columns of sand and/or gravel indicate that such loads can be approximated by a buoyancy-corrected Janssen-silo-theory-like relationship. Similar to conditions in storage silos filled with dry granular solids, most of the weight of the sand or gravel is supported by wall friction forces. Laboratory measurements of the loads on the floor at the base of the water-filled columns (up to 25-diameters tall) indicate that the extra floor-load from the addition of the granular solid never exceeded the load that would exist under an unsupported (wide) bed of submerged sand or gravel that has a total depth corresponding to only two column-diameters. The measured floorloads reached an asymptotic maximum value when the depth of granular material in the columns was only three or four pipe-diameters, and never increased further as the columns were filled to the top (e.g. up to heights of 10 to 25 diameters). The floor-loads were stable and remained the same for days after filling. Aggressive tapping (e.g. hitting the containing pipe on the outside, manually with a wrench up and down the height and around the circumference) could increase (and occasionally decrease) the floor load substantially, but there was no sudden collapse or slumping to a state without significant wall friction effects. Considerable effort was required, repeatedly tapping over almost the entire column wall periphery, in order to produce floor-loads that corresponded to the total buoyancy-corrected weight of granular material added to the columns. Projecting the observed laboratory behavior to field conditions would imply that a stable floor-load condition, with only a slightly higher total floor pressure than the preexisting hydrostatic-head, would exist after a water-filled bore-hole is filled with sand or gravel. Significant seismic vibration (either a large nearby event or many micro-seismic events over an extended period) would likely

  15. Study on Prompting Mechanism of Energy EFficiency Technology

    Broader source: [DOE]

    Information on energy efficient technologies, the obstacles surrounding their implementation, and the methods for prompting use of these technologies.

  16. Structure, Property, Processing Relationships in Metal Oxide...

    Energy Savers [EERE]

    Aeronautics and Space Administration (NASA) NIST Semiconductor Electronics Division ... Carnegie Mellon University, and Nearby NASA Glenn Research Center Collectively Have ...

  17. Conceptual optimization using genetic algorithms for tube in tube structures

    SciTech Connect (OSTI)

    Pârv, Bianca Roxana; Hulea, Radu; Mojolic, Cristian


    The purpose of this article is to optimize the tube in tube structural systems for tall buildings under the horizontal wind loads. It is well-known that the horizontal wind loads is the main criteria when choosing the structural system, the types and the dimensions of structural elements in the majority of tall buildings. Thus, the structural response of tall buildings under the horizontal wind loads will be analyzed for 40 story buildings and a total height of 120 meters; the horizontal dimensions will be 30m × 30m for the first two optimization problems and 15m × 15m for the third. The optimization problems will have the following as objective function the cross section area, as restrictions the displacement of the building< the admissible displacement (H/500), and as variables the cross section dimensions of the structural elements.

  18. New sign to identify Ames Laboratory | The Ames Laboratory

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

    sign to identify Ames Laboratory A new brick and metal sign will soon leave no doubt about the identity of the Ames Laboratory. The sign will feature a brick pedestal base topped with a two-sided metal panel with Ames Laboratory emblazoned in white lettering (8 1/2" tall) on a blue background. The sign panel is nearly 12- feet long. A vertical pylon with the Ames Laboratory logo will stand 8'6" tall. The sign is several years in the making with some of the original concepts developed

  19. The Ames Laboratory

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

    Insider Facilities New sign to identify Ames Laboratory A new brick and metal sign will soon leave no doubt about the identity of the Ames Laboratory. The sign will feature a brick pedestal base topped with a two-sided metal panel with Ames Laboratory emblazoned in white lettering (8 1/2" tall) on a blue background. The sign panel is nearly 12- feet long. A vertical pylon with the Ames Laboratory logo will stand 8'6" tall. READ MORE Research: New material discovery allows study of


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

    grid, nested model. The black star indicates the location of the Mokapu Point CDIP buoy used for model validation. The white squares represent the locations of model obstacles...

  1. FE Press Releases and Techlines | Department of Energy

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

    September 18, 2012 First-Generation Risk Profiles Help Predict CO2 Storage Site Obstacles In support of large-scale carbon capture, utilization and storage projects, a...

  2. Report of the Task Force on Nuclear Nonproliferation | Department...

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

    examining DOE's current areas of emphasis and potential misalignment, recommending actionable improvements, and suggesting how to overcome obstacles to successful implementation. ...

  3. Wind Project Permitting | Open Energy Information

    Open Energy Info (EERE)

    Development Code Beta Version 1.5. Accessed March 29, 2013. The model code presents strategies to remove obstacles, create incentives, and enact standards to encourage wind...

  4. Report: Human Capital Discussion and Observations

    Office of Environmental Management (EM)

    The Plan faces many challenges, but EM Executive Management is openly addressing the issues and obstacles through independent review and collaboration. The institution of the Plan ...

  5. Sandia Energy - Measurements of Thermal Stratification in a Homogenous...

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

    carbon dioxide. HCCI engines have diesel-engine efficiency but without the accompanying nitrogen oxide and particulate emissions. One of the main obstacles to HCCI development is...

  6. Drone Zone at Los Alamos ScienceFest

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

    There will be two obstacle courses, one for beginners and one for masters. Experts from Los Alamos National Laboratory's Unmanned Aerial Systems program will be there teaching ...

  7. Implementing a Zero Energy Ready Home Multifamily Project (Technical...

    Office of Scientific and Technical Information (OSTI)

    This report discusses challenges encountered, lessons learned, and how obstacles were overcome. Authors: Springer, David 1 ; German, Alea 1 + Show Author Affiliations Alliance ...

  8. Polyanionic Polymers with High Alkali-Ion Conductivity and Wide...

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

    In the search for suitable materials from which to construct high energy density solid state batteries, one of the principal obstacles has been the provision of a suitable ...

  9. Testing the Effectiveness of an Avian Flight Diverter for Reducing...

    Open Energy Info (EERE)

    California Abstract Distribution power lines are placed high overhead, safely out of human reach; however, for birds, these overhead wires are a potentially fatal obstacle....

  10. Assembling an On-Site Team | Department of Energy

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

    ... Team dedication and creativity are crucial as well, because these traits are essential for ... Navigating around these obstacles requires leadership, commitment, and creativity. ...

  11. Crystallization of a self-assembled three-dimensional DNA nanostructur...

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

    goal of producing nanocrystals to overcome the radiation-damage obstacle by the use of free-electron laser technology in the future. Date of online publication: Mon, ...

  12. Clean Energy Manufacturing Initiative | Department of Energy

    Broader source: (indexed) [DOE]

    Dave Danielson for an unforgettable dialogue on advances and obstacles in clean energy ... Read more Leadership Perspectives: The Opportunity for Clean Energy Manufacturing ...

  13. Syracuse Univesity Test Report On Uptake Factor Resulting From A Dropped Storage Container - Phase II

    SciTech Connect (OSTI)

    Gao, Zhi; Zhang, Jianshun S.


    Under certain circumstances, powder from an accidently dropped container can become airborne and inhaled by people nearby such as those who are moving the containers. The inhaled fine particles can deposit on respiratory tracts and lungs, causing asthma, lung cancer, and other acute respiratory illnesses and chronic symptoms. The objective of this study was to develop a standard procedure to measure the airborne concentrations of different size particles within the vicinity of a dropped container where a significant portion of the contained powder is ejected. Tungsten oxide (WO{sub 3}) was selected in this study to represent relatively heavy powders (7.16 g/cm3 specific gravity for WO{sub 3}). A typical can with the outer dimensions of 4.25 diameter and 4.875 tall was used as the container. The powder was dropped in two different configurations: 1) contained within a can covered by a lid that has a 0.25 diameter hole, and 2) contained within a can without a lid. The packing volume of the powder was 51.4 in3 (842.7 cm{sup 3}) and the target mass was 1936 g. The tests were carried out in a full-scale stainless steel environmental chamber with an interior volume of 852 ft3 (24.1 m3). The chamber system includes an internal recirculation loop with a rectangular air diffuser and 10 variable frequency drive fans to provide a typical room air recirculation flow pattern. Two air filters were installed in the chamber air supply duct and return duct to achieve the required low background particle concentration. The initial chamber air conditions were set at 70F ( 5F) and 50% ( 10%) RH. A supporting frame and releasing device were designed and built to trigger consistently the dropping of the can. The particle sampling inlet was placed 5 ft above the floor and 6 inches laterally away from the cans falling path. Concentrations of particles between 0.5 ?m and 20 ?m were recorded in units of mass and number of particles per unit volume. The data acquisition rate was once

  14. Another First at NSLS-II Construction Site

    ScienceCinema (OSTI)



    Workers at the NSLS-II ring building construction site recently completed the first complicated concrete pour for the approximately 19-ft.-tall walls of the Utility Tunnel. The continuous pour was the first of its kind, as previous pours have been for foo

  15. Mixing It Up

    Broader source: [DOE]

    PADUCAH, Ky. – A 150-foot-tall crane turns an eight-foot-diameter auger performing deep-soil mixing at the Paducah Gaseous Diffusion Plant’s southwest groundwater plume. More than 260 borings are being made to a depth of about 60 feet to remove a source of trichloroethene groundwater contamination.

  16. First TRUPACT-III Shipment Arrives Safely at the Waste Isolation...

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

    Lauren Milone 301-903-3731 Washington, D.C. - The U.S. Department ... The rectangular shipping package, at 8.2 feet wide, 8.7 feet tall, and 14 feet long, holds ...

  17. CX-005201: Categorical Exclusion Determination

    Broader source: [DOE]

    Tall Tower Wind Energy Monitoring and Numerical Model Validation in Southern NevadaCX(s) Applied: A9, B3.1Date: 02/14/2011Location(s): Searchlight, NevadaOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  18. CX-005020: Categorical Exclusion Determination

    Broader source: [DOE]

    Provision of Funds to the Idaho Department of Fish and Game For Purchase of the Tall Pines PropertyCX(s) Applied: B1.25Date: 01/05/2011Location(s): Kootenai County, IdahoOffice(s): Bonneville Power Administration

  19. AmeriFlux US-Los Lost Creek

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

    Desai, Ankur [University of Wisconsin


    This is the AmeriFlux version of the carbon flux data for the site US-Los Lost Creek. Site Description - Shrub wetland site, chosen to be representative of the wetlands within the WLEF tall tower flux footprint. This is a deciduous shrub wetland. Coniferous and grassy stands also exist within the WLEF flux footprint. Solar power. The site has excellent micrometeorological characteristics.

  20. Concrete Company Aims Higher for More Wind Energy

    Broader source: [DOE]

    Today, most steel towers that support utility-scale turbines stand about 80 meters tall, but the Tindall Corporation wants to go higher using precast concrete to raise turbines over 100 meters in height to capture stronger, steadier winds - and more energy.


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

    and Natural Resources provided a conservation measure of avoiding the introduction of invasive species in order to protect the integrity of nearby plant species of special...

  2. Microsoft Word - S05212_2008 Post-Closure InspRpt.doc

    Office of Legacy Management (LM)

    ... and maintenance program * Communicate with ... Salmon-Calendar Year 2008 U.S. Department of Energy Doc. No. ... businesses from nearby communities. * Continue the ...

  3. Environmental Justice and Federal Facilities: Recommendations...

    Broader source: (indexed) [DOE]

    ... improving the cleanup program and building a working ... environmental justice communities to more effectively ... demographic statistics of nearby cities and counties. ...

  4. American Recovery and Reinvestment Act (ARRA) FEMP Technical Assistance U.S. Army Project 181 Implementation Challenges in Deployment of an Energy Security Microgrid for Army Reserve Facilities located on the Former Fort Devens Army Base

    SciTech Connect (OSTI)

    Warwick, William M.


    This documents reports on a request for technical assistance from Fort Devens to analyze procurement of energy from nearby renewable generating resources.

  5. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    sensitivity (6) stars (6) detection (5) optics (5) planets (5) general and ... adaptive optics search for giant planets and brown dwarfs around nearby young stars. ...

  6. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    diagrams, as input into population synthesis codes to model the broadband spectral energy distributions (SEDs) of 50 nearby dwarf galaxies (6.5 < log Msub *Msub Sun <...


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

    Egg Ranch as fertilizer for its agricultural crops. - The Ak-Chin Indian Community ... Dairy Manure - Potato Processing Wastes - Food Waste - Other potential sources nearby ? ...

  8. Lower Sioux Indian Community Wind Energy Development

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

    Energy Goals * Provide clean and environmentally safe energy resources for tribal reservation by installing wind turbine in community * Sell excess power to nearby power utility * ...

  9. Energy Efficiency Upgrades Help Build Better Neighborhoods |...

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

    ... Program, Philadelphia and the nearby counties of Bucks, Chester, Delaware, and Montgomery have created EnergyWorks, a comprehensive energy solutions program for home and ...

  10. Small Business Innovation Research and Small Business Technology...

    Broader source: (indexed) [DOE]

    ... effectively opening up access to a lower cost of capital. ... of nearby existing solar panels and (2) moves in ... arrays, and reducing the costs of installing PV systems. ...