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1

Clustering in the 1.2 Jy IRAS Galaxy Redshift Survey II: Redshift Distortions and ?(r_p,?)  

E-Print Network (OSTI)

We examine the effect of redshift space distortions on the galaxy two-point correlation function $\\xi(r_p,\\pi)$ as a function of separations parallel ($r_p$) and perpendicular ($\\pi$) to the line of sight. We find that the relative velocity dispersion of pairs of IRAS galaxies is $\\sigma(r)= 317^{+40}_{-49}$ \\kms at $r=1 \\mpc$, consistent with previous estimates derived from optically selected galaxy catalogues. Unfortunately, the use of this result to estimate $\\Omega$ via the Cosmic Virial Theorem is thwarted by large systematic uncertainties. We also fit for the mean relative streaming velocity of pairs, $v_{12}(r)$, which describes the growth of fluctuations on both linear and nonlinear scales. We find that $v_{12}(r) = 167^{+99}_{-67}$ \\kms at $r=4$\\mpc, so that on average, approximately half the Hubble expansion velocity of pairs at this separation is canceled by infall. At $r=10$\\mpc, the amplitude of the streaming is lower and $v_{12}(r) = 109^{+64}_{-47} \\kms$. Linear perturbation theory then implies that $\\Omega^{0.6}/b =0.45^{+0.27}_{-0.18}$ on scales $\\sim 10-15 \\mpc$. The amplitude of $v_{12}(r)$ is sensitive to the assumed shape of $\\sigma(r)$; if the latter deviates substantially from a virialized form on small scale, our best fit amplitude of $v_{12}(r)$ can deviate by a factor of two.

Karl B Fisher; Marc Davis; Michael A Strauss; Amos Yahil; John P Huchra

1993-08-09T23:59:59.000Z

2

Gravitational Clustering in Redshift Space: Non-Gaussian Tail of the Cosmological Density Distribution Function  

E-Print Network (OSTI)

We study the non-Gaussian tail of the probability distribution function of density in cosmological N-Body simulations for a variety of initial conditions. We compare the behaviour of the non-Gaussian tail in the real space with that in the redshift space. The form of the PDF in redshift space is of great significance as galaxy surveys probe this and not the real space analogue predicted using theoretical models. We model the non-Gaussian tail using the halo model. In the weakly non-linear regime the moments of counts in cells in the redshift space approach the values expected from perturbation theory for moments in real space. We show that redshift space distortions in the non-linear regime dominate over signatures of initial conditions or the cosmological background. We illustrate this using Skewness and higher moments of counts in cells, as well as using the form of the non-Gaussian tail of the distribution function. We find that at scales smaller than the scale of non-linearity the differences in Skewness, etc. for different models are very small compared to the corresponding differences in real space. We show that bias also leads to smaller values of higher moments, but the redshift space distortions are typically the dominant effect.

J. S. Bagla; Suryadeep Ray

2006-04-28T23:59:59.000Z

3

The ESO Slice Project (ESP) Galaxy Redshift Survey. VII. The Redshift and Real-Space Correlation Functions  

E-Print Network (OSTI)

We present analyses of the two-point correlation properties of the ESP galaxy redshift survey. From the redshift-space correlation function xi(s), we see positive clustering out to separations ~50/h Mpc, with a smooth break on larger scales and zero-crossing between 60 and 80/h Mpc. xi(s) is reasonably well described by a shallow power law with \\gamma~1.5 between 3 and 50/h Mpc, while on smaller scales (0.2-2/h Mpc) it has a shallower slope (\\gamma~ 1). We examine the full effect of redshift-space distortions through the two-dimensional correlation function xi(rp,pi), from which we project out the real-space xi(r) below 10/h Mpc. This function is well described by a power-law model (r/r_o)^{-\\gamma}, with r_o=4.15^{+0.20}_{-0.21} h^{-1} Mpc and \\gamma=1.67^{+0.07}_{-0.09}. Comparison to other redshift surveys shows a consistent picture in which clustering remains positive out to separations of 50/h Mpc or larger, in substantial agreement with the results obtained from angular surveys like the APM and EDSGC. Also the shape of the two-point correlation function is remarkably unanimous among these data sets, in all cases requiring more power above 5/h Mpc (a `shoulder'), than a simple extrapolation of the canonical xi(r)=(r/5)^{-1.8}. xi(s) for volume-limited subsamples shows evidence of luminosity segregation only for the most luminous sample with M_{b_J}\\le -20.5. When redshift-space distortions are removed through projection of xi(rp,pi), however, a weak dependence on luminosity is seen at small separations also at fainter magnitudes. This effect is masked in redshift space, as the mean pairwise velocity dispersion experiences a parallel increase, basically erasing the effect of the clustering growth on xi(s).

L. Guzzo; J. G. Bartlett; A. Cappi; S. Maurogordato; E. Zucca; G. Zamorani; C. Balkowski; A. Blanchard; V. Cayatte; G. Chincarini; C. A. Collins; D. Maccagni; H. MacGillivray; R. Merighi; M. Mignoli; D. Proust; M. Ramella; R. Scaramella; G. M. Stirpe; G. Vettolani

1999-01-27T23:59:59.000Z

4

Real and Redshift-Space Clustering in the ESP Galaxy Redshift Survey  

E-Print Network (OSTI)

We discuss the two-point correlation properties of galaxies in the ESO Slice Project (ESP) redshift survey, both in redshift and real space. The redshift-space correlation function xi(s) for the whole magnitude-limited survey is well described by a power law with \\gamma ~ 1.55 between 3 and ~40/h Mpc, where it smoothly breaks down, crossing the zero value on scales as large as ~80/h Mpc. On smaller scales (0.2-2/h Mpc), the slope is shallower, mostly due to redshift-space depression by virialized structures. This effect is found to be enhanced by the J3 optimal-weighting estimator for xi. We explicitly evidence these effects by computing xi(r_p,pi) and the projected function w_p(r_p). In this way we recover the real-space correlation function xi(r), which we fit below 10/h Mpc with a power-law model. This gives a reasonable fit, with r_o=4.15^{+0.20}_{-0.21} /h Mpc and \\gamma=1.67^{+0.07}_{-0.09}. This results on xi(r) and xi(s), and the comparison with other surveys, clearly confirm how the shape of spatial correlations above ~3/h Mpc is characterised by a significant `shoulder' with respect to the small-scale ~ -1.8 power law, corresponding to a steepening of P(k) near the turnover.

L. Guzzo; J. G. Bartlett; A. Cappi

1998-10-12T23:59:59.000Z

5

The Redshift and Real-Space Correlation Functions from the ESP Galaxy Redshift Survey  

E-Print Network (OSTI)

We discuss the behaviour of the redshift- and real-space correlation functions from the ESO Slice Project (ESP) galaxy redshift survey. xi(s) for the whole survey is positive out to ~80/h Mpc, with a smooth break from a shallow power law. Comparison to xi(s) from two other wide-angle, moderately deep surveys, the LCRS and Stromlo-APM, shows a very good agreement of all data sets, despite the different selections and geometries. By projecting xi(r_p, pi), we recover the real--space correlation function xi(r), which below 10/h Mpc is reasonably well described by a power law xi(r) = (r/r_o)^{-\\gamma} with r_o=4.15^{+0.20}_{-0.21} /h Mpc and \\gamma=1.67^{+0.07}_{-0.09}. The same analysis, applied to four volume-limited subsamples, evidences a small but significant growth of clustering with luminosity (r_o varies from 3.4 to 5.2/h Mpc when the luminosity threshold is increased from -18. to -20).

L. Guzzo; J. G. Bartlett; A. Cappi

1998-10-06T23:59:59.000Z

6

Forecasting Cosmological Constraints from Redshift Surveys  

E-Print Network (OSTI)

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure, which depends both on the expansion rate of the Universe and our theory of gravity. In this paper we present a formalism for forecasting the constraints on the growth of structure which would arise in an idealized survey. This Fisher matrix based formalism can be used to study the power and aid in the design of future surveys.

Martin White; Yong-Seon Song; Will J. Percival

2008-10-08T23:59:59.000Z

7

The Universe Adventure - Redshift  

NLE Websites -- All DOE Office Websites (Extended Search)

Expansion of the Universe Expansion of the Universe Redshift Expansion of Space Redshifts Light The expansion of space redshifts light. As space expands, light waves get stretched and their wavelengths shift. The more that light is stretched, the longer its wavelengths become, and the color of each wave shifts toward the red end of the light spectrum. We say that this light is redshifted. The Doppler Effect in action. A moving fire truck's siren changes pitch as it moves past you. This is known as the Doppler Effect. To get a better idea of how this actually works, we'll look at a common phenomenon: the Doppler Effect. Imagine you hear a fire truck coming right toward you. As the truck approaches, the pitch of the siren gets higher and higher. As soon as the truck passes you however, the pitch drops lower as

8

High Redshift Supernova Rates  

E-Print Network (OSTI)

We use a sample of 42 supernovae detected with the Advanced Camera for Surveys on-board the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey to measure the rate of core collapse supernovae to z~0.7 and type Ia supernovae to z~1.6. This significantly increases the redshift range where supernova rates have been estimated from observations. The rate of core collapse supernovae can be used as an independent probe of the cosmic star formation rate. Based on the observations of 17 core collapse supernovae, we measure an increase in the core collapse supernova rate by a factor of 1.6 in the range 0.3rate. The increase in the rate in this redshift range in consistent with recent measurements of the star formation rate derived from UV-luminosity densities and IR datasets. Based on 25 type Ia supernovae, we find a SN Ia rate that is a factor 3-5 higher at z~1 compared to earlier estimates at lower redshifts (zrate traces a higher star formation rate at redshifts z>1 compared to low redshift. At higher redshift (z>1), we find a suggested decrease in the type Ia rate with redshift. This evolution of the Ia rate with redshift is consistent with a type Ia progenitor model where there is a substantial delay between the formation of the progenitor star and the explosion of the supernova. Assuming that the type Ia progenitor stars have initial main sequence masses 3-8 M_Sun, we find that 5-7% of the available progenitors explode as type Ia supernovae.

Tomas Dahlen; Louis-Gregory Strolger; Adam G. Riess; Bahram Mobasher; Ranga-Ram Chary; Christopher J. Conselice; Henry C. Ferguson; Andrew S. Fruchter; Mauro Giavalisco; Mario Livio; Piero Madau; Nino Panagia; John L. Tonry

2004-06-24T23:59:59.000Z

9

Redshift and Energy Conservation  

E-Print Network (OSTI)

It has always been considered a serious error to treat the cosmological redshift as a Doppler velocity effect rather than the result of space expansion. It is demonstrated here that in practical terms this is not the case, and that the apparent distance - redshift relation derived from a Doppler interpretation is reasonably consistent with supernova data (though not as good as the standard model with dark energy). The normal Doppler effect is examined in detail and shown to conserve energy as expected. Because of the equivalence between the general relativistic space expansion paradigm and the Doppler effect (as demonstrated) the long-standing problem of energy loss associated with the expansion of the Universe is treated in a similar manner to the normal well-behaved Doppler effect. The mechanism by which energy is conserved with the normal Doppler shift is applied to the cosmological redshift and the energy violation disappears. However, an additional luminosity-dependent recession factor is introduced. The effect on astronomical objects is examined and it is found to add only a small additional redshift to a body generating power by nuclear means but can be very large for objects powered by gravity. A possible connection to the claimed anomalous redshift of quasars is considered.

Alasdair Macleod

2004-07-14T23:59:59.000Z

10

Bayesian inference from photometric redshift surveys  

E-Print Network (OSTI)

We show how to enhance the redshift accuracy of surveys consisting of tracers with highly uncertain positions along the line of sight. Photometric surveys with redshift uncertainty delta_z ~ 0.03 can yield final redshift uncertainties of delta_z_f ~ 0.003 in high density regions. This increased redshift precision is achieved by imposing an isotropy and 2-point correlation prior in a Bayesian analysis and is completely independent of the process that estimates the photometric redshift. As a byproduct, the method also infers the three dimensional density field, essentially super-resolving high density regions in redshift space. Our method fully takes into account the survey mask and selection function. It uses a simplified Poissonian picture of galaxy formation, relating preferred locations of galaxies to regions of higher density in the matter field. The method quantifies the remaining uncertainties in the three dimensional density field and the true radial locations of galaxies by generating samples that are ...

Jasche, Jens

2011-01-01T23:59:59.000Z

11

Constraint on the cosmological f(R) model from the multipole power spectrum of the SDSS luminous red galaxy sample and prospects for a future redshift survey  

SciTech Connect

A constraint on the viable f(R) model is investigated by confronting theoretical predictions with the multipole power spectrum of the luminous red galaxy sample of the Sloan Digital Sky Survey, data release 7. We obtain a constraint on the Compton wavelength parameter of the f(R) model on the scales of cosmological large-scale structure. A prospect of constraining the Compton wavelength parameter with a future redshift survey is also investigated. The usefulness of the redshift-space distortion for testing the gravity theory on cosmological scales is demonstrated.

Yamamoto, Kazuhiro; Nakamura, Gen; Narikawa, Tatsuya; Sato, Takahiro [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Huetsi, Gert [Tartu Observatory, EE-61602 Torevere (Estonia)

2010-05-15T23:59:59.000Z

12

Redshift clustering in the Hubble Deep Field  

E-Print Network (OSTI)

We present initial results from a redshift survey carried out with the Low Resolution Imaging Spectrograph on the 10~m W. M. Keck Telescope in the Hubble Deep Field. In the redshift distribution of the 140 extragalactic objects in this sample we find 6 strong peaks, with velocity dispersions of ${\\sim}400${\\kms}. The areal density of objects within a particular peak, while it may be non-uniform, does not show evidence for strong central concentration. These peaks have characteristics (velocity dispersions, density enhancements, spacing, and spatial extent) similar to those seen in a comparable redshift survey in a different high galactic latitude field (Cohen et al 1996), confirming that the structures are generic. They are probably the high redshift counterparts of huge galaxy structures (``walls'') observed locally.

Judith G. Cohen; Lennox L. Cowie; David W. Hogg; Antoinette Songaila; Roger Blandford; Esther M. Hu; Patrick Shopbell

1996-08-20T23:59:59.000Z

13

Cyclotron emission effect on CMB spectral distortions  

E-Print Network (OSTI)

We investigated the role of the cyclotron emission (CE) associated to cosmic magnetic fields (MF) on the evolution of cosmic microwave background (CMB) spectral distortions. We computed the photon and energy injection rates by including spontaneous and stimulated emission and absorption. These CE rates have been compared with those of bremsstrahlung (BR) and double Compton scattering (DC), for realistic CMB distorted spectra at various cosmic epochs. For reasonable MF strengths we found that the CE contribution to the evolution of the CMB spectrum is much smaller than the BR and DC contributions. The constraints on the energy exchanges at various redshifts can be then derived, under quite general assumptions, by considering only Compton scattering (CS), BR, and DC, other than the considered dissipation process. Upper limits to the CMB polarization degree induced by CE have been estimated.

Carlo Burigana; Andrea Zizzo

2006-01-12T23:59:59.000Z

14

On the gravitational redshift  

E-Print Network (OSTI)

The study of the gravitational redshift -- a relative wavelength increase of $\\approx 2 \\times 10^{-6}$ was predicted for solar radiation by Einstein in 1908 -- is still an important subject in modern physics. In a dispute whether or not atom interferometry experiments can be employed for gravitational redshift measurements, two research teams have recently disagreed on the physical cause of the shift. Regardless of any discussion on the interferometer aspect -- we find that both groups of authors miss the important point that the ratio of gravitational to the electrostatic forces is generally very small. For instance, the gravitational force acting on an electron in a hydrogen atom situated in the Sun's photosphere to the electrostatic force between the proton and the electron is approximately $3 \\times 10^{-21}$. A comparison of this ratio with the predicted and observed solar redshift indicates a discrepancy of many orders of magnitude. Here we show, with Einstein's early assumption of the frequency of spectral lines depending only on the generating ion itself as starting point, that a solution can be formulated based on a two-step process in analogy with Fermi's treatment of the Doppler effect. It provides a sequence of physical processes in line with the conservation of energy and momentum resulting in the observed shift and does not employ a geometric description. The gravitational field affects the release of the photon and not the atomic transition. The control parameter is the speed of light. The atomic emission is then contrasted with the gravitational redshift of matter-antimatter annihilation events.

Klaus Wilhelm; Bhola N. Dwivedi

2013-07-01T23:59:59.000Z

15

Electric Power Waveform Distortion  

Science Conference Proceedings (OSTI)

Engineering issues regarding waveform distortion, harmonics, radio-frequency noise, and similar concerns have existed as long as there has been a power industry. These deal with consequences ranging from heating of transformers and machinery to telephone and radio interference. While waveform distortion has been around for a long time, the sources of harmonics and electromagnetic noise owned by the electricity customer have proliferated in recent years with the widespread usage of such things as switchin...

2012-05-23T23:59:59.000Z

16

The evolution of CMB spectral distortions in the early Universe  

E-Print Network (OSTI)

The energy spectrum of the cosmic microwave background (CMB) allows constraining episodes of energy release in the early Universe. In this paper we revisit and refine the computations of the cosmological thermalization problem. For this purpose a new code, called CosmoTherm, was developed that allows solving the coupled photon-electron Boltzmann equation in the expanding, isotropic Universe for small spectral distortion in the CMB. We explicitly compute the shape of the spectral distortions caused by energy release due to (i) annihilating dark matter; (ii) decaying relict particles; (iii) dissipation of acoustic waves; and (iv) quasi-instantaneous heating. We also demonstrate that (v) the continuous interaction of CMB photons with adiabatically cooling non-relativistic electrons and baryons causes a negative mu-type CMB spectral distortion of DI_nu/I_nu ~ 10^{-8} in the GHz spectral band. We solve the thermalization problem including improved approximations for the double Compton and Bremsstrahlung emissivities, as well as the latest treatment of the cosmological recombination process. At redshifts z injection because of (ii) and (iv) Pixie should allow to improve existing limits, while the CMB distortions caused by the other processes seem to remain unobservable with the currently proposed sensitivities and spectral bands of Pixie.

J. Chluba; R. A. Sunyaev

2011-09-29T23:59:59.000Z

17

A faint galaxy redshift survey behind massive clusters  

SciTech Connect

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

Frye, Brenda

1999-12-01T23:59:59.000Z

18

IMPROVED PHOTOMETRIC REDSHIFTS WITH SURFACE LUMINOSITY PRIORS  

SciTech Connect

We apply Bayesian statistics with prior probabilities of galaxy surface luminosity (SL) to improve photometric redshifts. We apply the method to a sample of 1266 galaxies with spectroscopic redshifts in the GOODS North and South fields at 0.1 {approx}< z {approx}< 2.0. We start with spectrophotometric redshifts (SPZs) based on Probing Evolution and Reionization Spectroscopically grism spectra, which cover a wavelength range of 6000-9000 A, combined with (U)BViz(JHK) broadband photometry in the GOODS fields. The accuracy of SPZ redshifts is estimated to be {sigma}({delta}(z)) = 0.035 with an systematic offset of -0.026, where {delta}(z) = {delta}z/(1 + z), for galaxies in redshift range of 0.5 {approx}< z {approx}< 1.25. The addition of the SL prior probability helps break the degeneracy of SPZ redshifts between low redshift 4000 A break galaxies and high-redshift Lyman break galaxies which are mostly catastrophic outliers. For the 1138 galaxies at z {approx}< 1.6, the fraction of galaxies with redshift deviation {delta}(z)>0.2 is reduced from 15.0% to 10.4%, while the rms scatter of the fractional redshift error does not change much.

Xia Lifang; Cohen, Seth; Malhotra, Sangeeta; Rhoads, James; Grogin, Norman; Windhorst, Rogier A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Hathi, Nimish P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Pirzkal, Nor; Xu Chun [Space Telescope Science Institute, Baltimore, MD 21218 (United States)], E-mail: lifang.xia@asu.edu

2009-07-15T23:59:59.000Z

19

Redshift of photons penetrating a hot plasma  

E-Print Network (OSTI)

A new interaction, plasma redshift, is derived, which is important only when photons penetrate a hot, sparse electron plasma. The derivation of plasma redshift is based entirely on conventional axioms of physics. When photons penetrate a cold and dense plasma, they lose energy through ionization and excitation, Compton scattering on the individual electrons, and Raman scattering on the plasma frequency. But in sparse hot plasma, such as in the solar corona, the photons lose energy also in plasma redshift. The energy loss per electron in the plasma redshift is about equal to the product of the photon's energy and one half of the Compton cross-section per electron. In quiescent solar corona, this heating starts in the transition zone to the corona and is a major fraction of the coronal heating. Plasma redshift contributes also to the heating of the interstellar plasma, the galactic corona, and the intergalactic plasma. Plasma redshift explains the solar redshifts, the redshifts of the galactic corona, the cosmological redshifts, the cosmic microwave background, and the X-ray background. The plasma redshift explains the observed magnitude-redshift relation for supernovae SNe Ia without the big bang, dark matter, or dark energy. There is no cosmic time dilation. The universe is not expanding. The plasma redshift, when compared with experiments, shows that the photons' classical gravitational redshifts are reversed as the photons move from the Sun to the Earth. This is a quantum mechanical effect. As seen from the Earth, a repulsion force acts on the photons. This means that there is no need for Einstein's Lambda term. The universe is quasi-static, infinite, and everlasting.

Ari Brynjolfsson

2004-01-21T23:59:59.000Z

20

QSO hosts and companions at higher redshifts  

E-Print Network (OSTI)

This review presents the current state of work on QSO hosts and companions at redshifts above 1. This includes the properties of QSO host galaxies, such as size, scale length, and luminosity, and morphology, as they appear to change with redshift and radio activity. This leads to a view of how the properties of galaxies that host QSOs change with cosmic time. I also review studies of the galaxy companions to QSOs at higher redshifts, and studies of the emission line gas in and around higher redshift QSOs. These topics should see great progress in the next decade.

J. B. Hutchings

2001-07-09T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Bayesian Photometric Redshifts for Weak Lensing Applications  

E-Print Network (OSTI)

The next generation of weak gravitational lensing surveys is capable of generating good measurements of cosmological parameters, provided that, amongst other requirements, adequate redshift information is available for the background galaxies that are measured. It is frequently assumed that photometric redshift techniques provide the means to achieve this. Here we compare Bayesian and frequentist approaches to photometric redshift estimation, particularly at faint magnitudes. We identify and discuss the biases that are inherent in the various methods, and describe an optimum Bayesian method for extracting redshift distributions from photometric data.

Edward Edmondson; Lance Miller; Christian Wolf

2006-07-13T23:59:59.000Z

22

PHOTOMETRIC REDSHIFT PROBABILITY DISTRIBUTIONS FOR GALAXIES IN THE SDSS DR8  

Science Conference Proceedings (OSTI)

We present redshift probability distributions for galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 8 imaging data. We used the nearest-neighbor weighting algorithm to derive the ensemble redshift distribution N(z), and individual redshift probability distributions P(z) for galaxies with r training galaxies with known redshifts such that their density distribution in five-dimensional color-magnitude space was proportional to that of the photometry-only sample, producing a nearly fair sample in that space. We estimated the ensemble N(z) of the photometric sample by constructing a weighted histogram of the training-set redshifts. We derived P(z)'s for individual objects by using training-set objects from the local color-magnitude space around each photometric object. Using the P(z) for each galaxy can reduce the statistical error in measurements that depend on the redshifts of individual galaxies. The spectroscopic training sample is substantially larger than that used for the DR7 release. The newly added PRIMUS catalog is now the most important training set used in this analysis by a wide margin. We expect the primary sources of error in the N(z) reconstruction to be sample variance and spectroscopic failures: The training sets are drawn from relatively small volumes of space, and some samples have large incompleteness. Using simulations we estimated the uncertainty in N(z) due to sample variance at a given redshift to be {approx}10%-15%. The uncertainty on calculations incorporating N(z) or P(z) depends on how they are used; we discuss the case of weak lensing measurements. The P(z) catalog is publicly available from the SDSS Web site.

Sheldon, Erin S. [Brookhaven National Laboratory, Bldg 510, Upton, NY 11973 (United States); Cunha, Carlos E. [Department of Physics, University of Michigan, 500 East University, Ann Arbor, MI 48109-1120 (United States); Mandelbaum, Rachel [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States); Brinkmann, J. [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Weaver, Benjamin A. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

2012-08-01T23:59:59.000Z

23

Redshift of photons penetrating a hot plasma  

E-Print Network (OSTI)

A new interaction, plasma redshift, is derived, which is important only when photons penetrate a hot, sparse electron plasma. The derivation of plasma redshift is based entirely on conventional axioms of physics, without any new assumptions. The calculations are only more exact than those usually found in the literature. When photons penetrate a cold and dense electron plasma, they lose energy through ionization and excitation, through Compton scattering on the individual electrons, and through Raman scattering on the plasma frequency. But when the plasma is very hot and has low density, such as in the solar corona, the photons lose energy also in plasma redshift, which is an interaction with the electron plasma. The energy loss of a photon per electron in the plasma redshift is about equal to the product of the photon’s energy and one half of the Compton cross-section per electron. This energy loss (plasma redshift of the photons) consists of very small quanta, which are absorbed by the plasma and cause a significant heating. In quiescent solar corona, this heating starts in the transition zone to the solar corona and is a major fraction of the coronal heating. Plasma redshift contributes also to the heating of the interstellar plasma, the galactic corona, and the intergalactic plasma. Plasma redshift explains

Ari Brynjolfsson

2005-01-01T23:59:59.000Z

24

Does the Hubble Redshift Flip Photons and Gravitons?  

E-Print Network (OSTI)

Due to the Hubble redshift, photon energy, chiefly in the form of CMBR photons, is currently disappearing from the universe at the rate of nearly 10^55 erg s^-1. An ongoing problem in cosmology concerns the fate of this energy. In one interpretation it is irretrievably lost, i.e., energy is not conserved on the cosmic scale. Here we consider a different possibility which retains universal energy conservation. If gravitational energy is redshifted in the same manner as photons, then it can be shown that the cosmic redshift removes gravitational energy from space at about the same rate as photon energy. Treating gravitational potential energy conventionally as negative energy, it is proposed that the Hubble shift 'flips' positive energy (photons) to negative energy (gravitons) and vice versa. The lost photon energy would thus be directed towards gravitation, making gravitational energy wells more negative. Conversely, within astrophysical bodies of sufficient size, the flipping of gravitons to photons would give rise to a 'Hubble luminosity' of magnitude -UH, where U is the internal gravitational potential energy of the object and H the Hubble constant. Evidence of such an energy release is presented in bodies ranging from planets, white dwarfs and neutron stars to supermassive black holes and the visible universe.

Matthew R. Edwards

2011-11-09T23:59:59.000Z

25

Redshift indicators for gamma-ray bursts  

E-Print Network (OSTI)

The measure of the distances and luminosities of gamma-ray bursts (GRBs) led to the discovery that many GRB properties are strongly correlated with their intrinsic luminosity, leading to the construction of reliable luminosity indicators. These GRB luminosity indicators have quickly found applications, like the construction of 'pseudo-redshifts', or the measure of luminosity distances, which can be computed independently of the measure of the redshift. In this contribution I discuss various issues connected with the construction of luminosity-redshift indicators for gamma-ray bursts.

J-L. Atteia

2005-05-04T23:59:59.000Z

26

Globally Optimal Estimation of Nonrigid Image Distortion  

Science Conference Proceedings (OSTI)

Image alignment in the presence of non-rigid distortions is a challenging task. Typically, this involves estimating the parameters of a dense deformation field that warps a distorted image back to its undistorted template. Generative approaches based ... Keywords: Combine generative and discriminative approaches, Computer vision, Distortion estimation, Feature correspondence, Global optimum, Image alignment, Image registration, Iterative approach, Motion and tracking, Nonrigid deformation, Physics-based vision, Water distortion

Yuandong Tian; Srinivasa G. Narasimhan

2012-07-01T23:59:59.000Z

27

Photon Redshift in a Magnetic field  

E-Print Network (OSTI)

Previous results from the authors concerning the arising a tiny photon anomalous paramagnetic moment are also interpreted as a red-shift in analogy to the gravitational known effect. It is due to the photon interaction with the magnetized virtual electron-positron background which withdraw transverse momentum from photons and is polarization-dependent. If the photon frequency red-shift implies a change in time, a clock would go faster for increasing magnetic field intensity.

Rojas, H Pérez

2010-01-01T23:59:59.000Z

28

Photometric redshifts from reconstructed QSO templates  

E-Print Network (OSTI)

From SDSS commissioning photometric and spectroscopic data, we investigate the utility of photometric redshift techniques to the task of estimating QSO redshifts. We consider empirical methods (e.g. nearest-neighbor searches and polynomial fitting), standard spectral template fitting and hybrid approaches (i.e. training spectral templates from spectroscopic and photometric observations of QSOs). We find that in all cases, due to the presence of strong emission-lines within the QSO spectra, the nearest-neighbor and template fitting methods are superior to the polynomial fitting approach. Applying a novel reconstruction technique, we can, from the SDSS multicolor photometry, reconstruct a statistical representation of the underlying SEDs of the SDSS QSOs. Although, the reconstructed templates are based on only broadband photometry the common emission lines present within the QSO spectra can be recovered in the resulting spectral energy distributions. The technique should be useful in searching for spectral differences among QSOs at a given redshift, in searching for spectral evolution of QSOs, in comparing photometric redshifts for objects beyond the SDSS spectroscopic sample with those in the well calibrated photometric redshifts for objects brighter than 20th magnitude and in searching for systematic and time variable effects in the SDSS broad band photometric and spectral photometric calibrations.

Tamas Budavari; Istvan Csabai; Alexander S. Szalay; Andrew J. Connolly; Gyula P. Szokoly

2001-06-03T23:59:59.000Z

29

Quantum effect on luminosity-redshift relation  

E-Print Network (OSTI)

There are many different proposals for a theory of quantum gravity. Even leaving aside the fundamental difference among theories such as the string theory and the non-perturbative quantum gravity, we are still left with many ambiguities (and/or parameters to be determined) with regard to the choice of variables, the choice of related groups, etc. Loop quantum gravity is also in such a state. It is interesting to search for experimental observables to distinguish these quantum schemes. This paper investigates the loop quantum gravity effect on luminosity-redshift relation. The quantum bounce behavior of loop quantum cosmology is found to result in multivalued correspondence in luminosity-redshift relation. And the detail multivalued behavior can tell the difference of different quantum parameters. The inverse volume quantum correction does not result in bounce behavior in this model, but affects luminosity-redshift relation also significantly.

Li-Fang Li; Jian-Yang Zhu

2010-06-28T23:59:59.000Z

30

Inlet distortion generation for a transonic compressor .  

E-Print Network (OSTI)

??A single-stage transonic research compressor and test rig are to be used to obtain data on the effect of inlet flow distortion on compressor (and… (more)

Papamarkos, Ioannis.

2004-01-01T23:59:59.000Z

31

POLARIZED RADIO SOURCES: A STUDY OF LUMINOSITY, REDSHIFT, AND INFRARED COLORS  

SciTech Connect

The Dominion Radio Astrophysical Observatory Deep Field polarization study has been matched with the Spitzer Wide-Area Infrared Extragalactic Survey of the European Large Area Infrared Space Observatory Survey North 1 field. We have used Very Large Array observations with a total intensity rms of 87 {mu}Jy beam{sup -1} to match SWIRE counterparts to the radio sources. Infrared color analysis of our radio sample shows that the majority of polarized sources are elliptical galaxies with an embedded active galactic nucleus. Using available redshift catalogs, we found 429 radio sources of which 69 are polarized with redshifts in the range of 0.04 < z < 3.2. We find no correlation between redshift and percentage polarization for our sample. However, for polarized radio sources, we find a weak correlation between increasing percentage polarization and decreasing luminosity.

Banfield, Julie K.; George, Samuel J.; Taylor, A. Russ; Stil, Jeroen M. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Calgary, Alberta, T2N 1N4 (Canada); Kothes, Roland [Dominion Radio Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council Canada, Penticton, BC V2A 6J9 (Canada); Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

2011-05-20T23:59:59.000Z

32

Redshift Surveys with 2dF  

E-Print Network (OSTI)

We report on the 2dF Galaxy and QSO Redshift Surveys now in progress with the Two Degree Field facility at the Anglo-Australian Observatory. We describe the 2dF instrumentation, outline the scientific aims of the surveys and their current status, and present some initial results.

Matthew Colless; Brian Boyle

1997-10-24T23:59:59.000Z

33

Probing black holes at low redshift using LISA EMRI observations  

E-Print Network (OSTI)

One of the most exciting potential sources of gravitational waves for the Laser Interferometer Space Antenna (LISA) are the inspirals of approximately solar mass compact objects into massive black holes in the centres of galaxies - extreme mass ratio inspirals (EMRIs). LISA should observe between a few tens and a few hundred EMRIs over the mission lifetime, mostly at low redshifts (z measurement of the parameters of the host system to unprecendented precision. LISA EMRI observations will thus offer a new and unique way to probe black holes at low redshift. In this article we provide a description of the population of EMRI events that LISA is likely to observe, and describe how the numbers of events vary with changes in the underlying assumptions about the black hole population. We also provide fitting functions that characterise LISA's ability to detect EMRIs and which will allow LISA event rates to be computed for arbitrary population models. We finish with a discussion of an ongoing programme that will use these results to assess what constraints LISA observations could place on galaxy evolution models.

Jonathan R Gair

2008-11-02T23:59:59.000Z

34

REDSHIFT CATALOG FOR SWIFT LONG GAMMA-RAY BURSTS  

Science Conference Proceedings (OSTI)

We present a catalog of the redshifts for most long-duration gamma-ray bursts (GRBs) by Swift from 2004 December 20 to 2008 July 23 (258 bursts in total). All available information is collected, including spectroscopic redshifts, photometric redshift limits, and redshifts calculated from various luminosity relations. Error bars for the redshifts derived from the luminosity relations are asymmetric, with tails extended to the high-redshift end, and this effect is evaluated by looking at the 30% of Swift bursts with spectroscopic redshifts. A simulation is performed to eliminate this asymmetric effect, and the resultant redshift distribution is deconvolved. We test and confirm this simulation on the sample of bursts with known spectroscopic redshifts and then apply it to the 70% of Swift bursts that do not have spectroscopic measures. A final intrinsic redshift distribution is then made for almost all Swift bursts, and the efficiency of the spectroscopic detections is evaluated. The efficiency of spectroscopic redshifts varies from near unity at low redshift to 0.5 at z = 1, to near 0.3 at z = 4, and to 0.1 at z = 6. We also find that the fraction of GRBs with z>5 is {approx}10%, and this fraction is compared with simulations from a cosmological model.

Xiao Limin; Schaefer, Bradley E., E-mail: lxiao1@lsu.edu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States)

2011-04-20T23:59:59.000Z

35

A simple empirical redshift indicator for gamma-ray bursts  

E-Print Network (OSTI)

We propose a new empirical redshift indicator for gamma-ray bursts. This indicator is easily computed from the gamma-ray burst spectral parameters, and its duration, and it provides ``pseudo-redshifts'' accurate to a factor two. Possible applications of this redshift indicator are briefly discussed.

J-L Atteia

2003-04-17T23:59:59.000Z

36

IMAGING OF LOW REDSHIFT QSOs WITH WFPC2  

E-Print Network (OSTI)

Observations with the PC2 CCD of the Hubble Space Telescope are described of two bright QSOs of redshift ~0.3. 1403+434 is IR-bright and radio-quiet, and 2201+315 is radio-loud with extended structure. Exposures were taken with the F702W and F555W filters. The images are deconvolved on their own and combined with 0.5 arcsec ground-based images. Both host galaxies have the form and luminosity of bright ellipticals, with nuclei of 1-2 times higher luminosity. 1403+434 is strongly interacting while 2201+315 may be in later stages of a merger, both with a smaller companion. Both host galaxies have compact knots and other small-scale peculiar features. Some general remarks are made based on the total program sample of 6 QSOs.

J. B. Hutchings; S. C. Morris

1995-02-07T23:59:59.000Z

37

Redshifts of the Long Gamma-Ray Bursts  

E-Print Network (OSTI)

The low energy spectra of some gamma-ray bursts' show excess components beside the power-law dependence. The consequences of such a feature allows to estimate the gamma photometric redshift of the long gamma-ray bursts in the BATSE Catalog. There is good correlation between the measured optical and the estimated gamma photometric redshifts. The estimated redshift values for the long bright gamma-ray bursts are up to z=4, while for the the faint long bursts - which should be up to z=20 - the redshifts cannot be determined unambiguously with this method. The redshift distribution of all the gamma-ray bursts with known optical redshift agrees quite well with the BATSE based gamma photometric redshift distribution.

Z. Bagoly; I. Csabai; A. Meszaros; P. Meszaros; I. Horvath; L. G. Balazs; R. Vavrek

2007-04-06T23:59:59.000Z

38

Atomic carbon at redshift ~2.5  

E-Print Network (OSTI)

Using the IRAM 30m telescope we detected the lower fine structure line of neutral carbon towards three high--redshift sources: IRAS FSC10214 (z=2.3), SMMJ14011+0252 (z=2.5) and H1413+117 (Cloverleaf quasar, z=2.5). SMMJ14011+0252 is the first high--redshift, non--AGN source in which CI has been detected. The CI(1-0) line from FSC10214 is almost an order of magnitude weaker than previously claimed, while our detection in the Cloverleaf is in good agreement with earlier observations. The CI(1-0) linewidths are similar to the CO widths, indicating that both lines trace similar regions of molecular gas on galactic scales. Derived CI masses for all three objects are of order few 10^7 solar masses and the implied CI(1-0)/CO(3-2) line luminosity ratio is about 0.2. This number is similar to values found in local galaxies. We derive a CI abundance of 5x10^{-5} which implies significant metal enrichment of the cold molecular gas at redshifts 2.5 (age of the universe 2.7 Gyr). We conclude that the physical properties of systems at large lookback times are similar to today's starburst/AGN environments.

A. Weiss; D. Downes; C. Henkel; F. Walter

2004-09-29T23:59:59.000Z

39

Refractive shape from light field distortion  

E-Print Network (OSTI)

Acquiring transparent, refractive objects is challenging as these kinds of objects can only be observed by analyzing the distortion of reference background patterns. We present a new, single image approach to reconstructing ...

Wetzstein, Gordon

40

Photometric Redshifts for the SDSS Early Data Release  

E-Print Network (OSTI)

The Early Data Release from the Sloan Digital Sky survey provides one of the largest multicolor photometric catalogs currently available to the astronomical community. In this paper we present the first application of photometric redshifts to the $\\sim 6$ million extended sources within these data (with 1.8 million sources having $r' Utilizing a range of photometric redshift techniques, from empirical to template and hybrid techniques, we investigate the statistical and systematic uncertainties present within the redshift estimates for the EDR data. For $r'list the current caveats and issues that should be understood before using these photometric redshifts in statistical analyses of the SDSS galaxies.

Istvan Csabai; Tamas Budavari; Andrew J. Connolly; Alexander S. Szalay; Zsuzsanna Gyory; Narciso Benitez; Jim Annis; Jon Brinkmann; Daniel Eisenstein; Masataka Fukugita; Jim Gunn; Stephen Kent; Robert Lupton; Robert C. Nichol; Chris Stoughton

2002-11-05T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Noncontacting Laser Scanner for Fuel Assembly Distortion Measurement  

Science Conference Proceedings (OSTI)

The distortion of fuel assemblies and bundles due to in-reactor exposure is a problem that has the potential to significantly affect the operations of both BWRs and PWRs. The distortion can take many shapes of axial, lateral and torsional displacements, with common distortions manifested as bows (such as C, S, and W shapes). Such distortion has implications from fuel ...

2012-09-30T23:59:59.000Z

42

Zigzag laser with reduced optical distortion  

DOE Patents (OSTI)

The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends. 11 figures.

Albrecht, G.F.; Comaskey, B.; Sutton, S.B.

1994-04-19T23:59:59.000Z

43

Boron abundance and solar neutrino spectrum distortion  

E-Print Network (OSTI)

The presence of neutrinos from Boron decay in the flux observed on Earth is attested by the observation of their energy spectrum. Possible distortions of the spectrum investigated in current detectors are often interpreted in terms of evidence in favour or against various schemes of neutrino oscillations. We stress here that a distortion of the spectrum at high energies could also result from an increase in the ratio of neutrinos originating from ($^3$He+p) and $^8$B reactions. While a $^8$B neutrino depletion would contribute to this effect, an increase in the Hep contribution seems also needed to reproduce the preliminary data.

R. Escribano; J. -M. Frere; A. Gevaert; D. Monderen

1998-05-06T23:59:59.000Z

44

Gravitational lens magnification by Abell 1689: Distortion of the background galaxy luminosity function  

E-Print Network (OSTI)

Gravitational lensing magnifies the luminosity of galaxies behind the lens. We use this effect to constrain the total mass in the cluster Abell 1689 by comparing the lensed luminosities of background galaxies with the luminosity function of an undistorted field. Since galaxies are assumed to be a random sampling of luminosity space, this method is not limited by clustering noise. We use photometric redshift information to estimate galaxy distance and intrinsic luminosity. Knowing the redshift distribution of the background population allows us to lift the mass/background degeneracy common to lensing analysis. In this paper we use 9 filters observed over 12 hours with the Calar Alto 3.5m telescope to determine the redshifts of 1000 galaxies in the field of Abell 1689. Using a complete sample of 151 background galaxies we measure the cluster mass profile. We find that the total projected mass interior to 0.25h^(-1)Mpc is (0.48 +/- 0.16) * 10^(15)h^(-1) solar masses, where our error budget includes uncertainties from the photometric redshift determination, the uncertainty in the off-set calibration and finite sampling. This result is in good agreement with that found by number count and shear-based methods and provides a new and independent method to determine cluster masses.

S. Dye; A. N. Taylor; E. M. Thommes; K. Meisenheimer; C. Wolf; J. A. Peacock

2000-02-01T23:59:59.000Z

45

Extending the redshift-distance relation in Cosmological General Relativity to higher redshifts  

E-Print Network (OSTI)

The redshift-distance modulus relation, the Hubble Diagram, derived from Cosmological General Relativity has been extended to arbitrarily large redshifts. Numerical methods were employed and a density function was found that results in a valid solution of the field equations at all redshifts. The extension has been compared to 302 type Ia supernova data as well as to 69 Gamma-ray burst data. The latter however do not not truly represent a `standard candle' as the derived distance modulii are not independent of the cosmology used. Nevertheless the analysis shows a good fit can be achieved without the need to assume the existence of dark matter. The Carmelian theory is also shown to describe a universe that is always spatially flat. This results from the underlying assumption of the energy density of a cosmological constant $\\Omega_{\\Lambda} = 1$, the result of vacuum energy. The curvature of the universe is described by a \\textit{spacevelocity} metric where the energy content of the curvature at any epoch is $\\Omega_K = \\Omega_{\\Lambda} - \\Omega = 1-\\Omega$, where $\\Omega$ is the matter density of the universe. Hence the total density is always $\\Omega_K + \\Omega = 1$

John G. Hartnett

2007-05-22T23:59:59.000Z

46

Caltech Faint Galaxy Redshift Survey VII: Data Analysis Techniques and Redshifts in the Field J0053+1234  

E-Print Network (OSTI)

We present the techniques used to determine redshifts and to characterize the spectra of objects in the Caltech Faint Galaxy Redshift Survey in terms of spectral classes and redshift quality classes. These are then applied to spectra from an investigation of a complete sample of objects with $K_s<20$ mag in a 2 by 7.3 arcmin^2 field at J005325+1234. Redshifts were successfully obtained for 163 of the 195 objects in the sample; these redshifts lie in the range [0.173, 1.44] and have a median of 0.58 (excluding 24 Galactic stars). The sample includes two broad lined AGNs and one QSO.

Judith G. Cohen; David W. Hogg; Michael A. Pahre; Roger Blandford; Patrick L. Shopbell; Kevin Richberg

1998-09-05T23:59:59.000Z

47

ALMA REDSHIFTS OF MILLIMETER-SELECTED GALAXIES FROM THE SPT SURVEY: THE REDSHIFT DISTRIBUTION OF DUSTY STAR-FORMING GALAXIES  

SciTech Connect

Using the Atacama Large Millimeter/submillimeter Array, we have conducted a blind redshift survey in the 3 mm atmospheric transmission window for 26 strongly lensed dusty star-forming galaxies (DSFGs) selected with the South Pole Telescope. The sources were selected to have S{sub 1.4{sub mm}} > 20 mJy and a dust-like spectrum and, to remove low-z sources, not have bright radio (S{sub 843{sub MHz}} < 6 mJy) or far-infrared counterparts (S{sub 100{sub {mu}m}} < 1 Jy, S{sub 60{sub {mu}m}} < 200 mJy). We robustly detect 44 line features in our survey, which we identify as redshifted emission lines of {sup 12}CO, {sup 13}CO, C I, H{sub 2}O, and H{sub 2}O{sup +}. We find one or more spectral features in 23 sources yielding a {approx}90% detection rate for this survey; in 12 of these sources we detect multiple lines, while in 11 sources we detect only a single line. For the sources with only one detected line, we break the redshift degeneracy with additional spectroscopic observations if available, or infer the most likely line identification based on photometric data. This yields secure redshifts for {approx}70% of the sample. The three sources with no lines detected are tentatively placed in the redshift desert between 1.7 < z < 2.0. The resulting mean redshift of our sample is z-bar = 3.5. This finding is in contrast to the redshift distribution of radio-identified DSFGs, which have a significantly lower mean redshift of z-bar = 2.3 and for which only 10%-15% of the population is expected to be at z > 3. We discuss the effect of gravitational lensing on the redshift distribution and compare our measured redshift distribution to that of models in the literature.

Weiss, A. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)] [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); De Breuck, C.; Aravena, M.; Biggs, A. D. [European Southern Observatory, Karl-Schwarzschild Strasse, D-85748 Garching bei Muenchen (Germany)] [European Southern Observatory, Karl-Schwarzschild Strasse, D-85748 Garching bei Muenchen (Germany); Marrone, D. P.; Bothwell, M. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)] [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Vieira, J. D.; Bock, J. J. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)] [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Aguirre, J. E. [University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States)] [University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Aird, K. A. [University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)] [University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Ashby, M. L. N.; Bayliss, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)] [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bethermin, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu - CNRS - Universite Paris Diderot, CEA-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette (France)] [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu - CNRS - Universite Paris Diderot, CEA-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Bradford, C. M. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States)] [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Chapman, S. C. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 3J5 Canada (Canada)] [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 3J5 Canada (Canada); and others

2013-04-10T23:59:59.000Z

48

Improving Photometric Redshifts using GALEX Observations for the SDSS Stripe 82 and the Next Generation of SZ Cluster Surveys  

E-Print Network (OSTI)

Four large-area Sunyaev-Zeldovich (SZ) experiments -- APEX-SZ, SPT, ACT, and Planck -- promise to detect clusters of galaxies through the distortion of Cosmic Microwave Background photons by hot (> 10^6 K) cluster gas (the SZ effect) over thousands of square degrees. A large observational follow-up effort to obtain redshifts for these SZ-detected clusters is under way. Given the large area covered by these surveys, most of the redshifts will be obtained via the photometric redshift (photo-z) technique. Here we demonstrate, in an application using ~3000 SDSS stripe 82 galaxies with r<20, how the addition of GALEX photometry (FUV, NUV) greatly improves the photometric redshifts of galaxies obtained with optical griz or ugriz photometry. In the case where large spectroscopic training sets are available, empirical neural-network-based techniques (e.g., ANNz) can yield a photo-z scatter of $\\sigma_z = 0.018 (1+z)$. If large spectroscopic training sets are not available, the addition of GALEX data makes possible the use simple maximum likelihood techniques, without resorting to Bayesian priors, and obtains $\\sigma_z=0.04(1+z)$, accuracy that approaches the accuracy obtained using spectroscopic training of neural networks on ugriz observations. This improvement is especially notable for blue galaxies. To achieve these results, we have developed a new set of high resolution spectral templates based on physical information about the star formation history of galaxies. We envision these templates to be useful for the next generation of photo-z applications. We make our spectral templates and new photo-z catalogs available to the community at http://www.ice.csic.es/personal/jimenez/PHOTOZ .

Michael D. Niemack; Raul Jimenez; Licia Verde; Felipe Menanteau; Ben Panter; David Spergel

2008-03-21T23:59:59.000Z

49

Thermally induced wave-front distortions in laser windows  

SciTech Connect

A simple analytical expression is given for wave-front distortions and birefringence due to heating in laser windows. (AIP)

Greninger, C.E.

1986-08-01T23:59:59.000Z

50

The Environment of Galaxies at Low Redshift  

E-Print Network (OSTI)

We compare environmental effects in two analogous samples of galaxies, one from the Sloan Digital Sky Survey (SDSS) and the other from a semi-analytic model (SAM) based on the Millennium Simulation (MS), to test to what extent current SAMs of galaxy formation are reproducing environmental effects. We estimate the large-scale environment of each galaxy using a Bayesian density estimator based on distances to all ten nearest neighbors and compare broad-band photometric properties of the two samples as a function of environment. The feedbacks implemented in the semi-analytic model produce a qualitatively correct galaxy population with similar environmental dependence as that seen in SDSS galaxies. In detail, however, the colors of MS galaxies exhibit an exaggerated dependence on environment: the field contains too many blue galaxies while clusters contain too many red galaxies, compared to the SDSS sample. We also find that the MS contains a population of highly clustered, relatively faint red galaxies with velocity dispersions comparable to their Hubble flow. Such high-density galaxies, if they exist, would be overlooked in any low-redshift survey since their membership to a cluster cannot be determined due to the "Fingers of God" effect.

Nicolas B. Cowan; Zeljko Ivezic

2008-01-01T23:59:59.000Z

51

Forecasts for CMB ?- and i-type spectral distortion constraints on the primordial power spectrum on scales 8 < k < 10^4 Mpc^-1 with the future Pixie-like experiments  

E-Print Network (OSTI)

Silk damping at redshifts 1.5 x 10^4 < z < 2 x 10^6 erases CMB anisotropies on scales corresponding to the comoving wavenumbers 8 < k < 10^4 Mpc^-1 (10^5 < \\ell < 10^8). This dissipated energy is gained by the CMB monopole, creating distortions from a blackbody in the CMB spectrum of the \\mu-type and the i-type. We study, using Fisher matrices, the constraints we can get from measurements of these spectral distortions on the primordial power spectrum from future experiments such as Pixie, and how these constraints change as we change the frequency resolution and the sensitivity of the experiment. We show that the additional information in the shape of the $i$-type distortions, in combination with the \\mu-type distortions, allows us to break the degeneracy between the amplitude and the spectral index of the power spectrum on these scales and leads to much tighter constraints. We quantify the information contained in both the \\mu-type distortions and the i-type distortions taking into account the partial degeneracy with the y-type distortions and the temperature of the blackbody part of the CMB. We also calculate the constraints possible on the primordial power spectrum when the spectral distortion information is combined with the CMB anisotropies measured by the WMAP, SPT, ACT and Planck experiments.

Rishi Khatri; Rashid A. Sunyaev

2013-03-28T23:59:59.000Z

52

Clustering of Galaxies in a Hierarchical Universe: III. Mock Redshift Surveys  

E-Print Network (OSTI)

This is the third paper in a series which combines N-body simulations and semi-analytic modelling to provide a fully spatially resolved simulation of the galaxy formation and clustering processes. Here we extract mock redshift surveys from our simulations: a Cold Dark Matter model with either Omega_0=1 (tauCDM) or Omega_0=0.3 and Lambda=0.7 (LambdaCDM). We compare the mock catalogues with the northern region (CfA2N) of the Center for Astrophysics (CfA) Redshift Surveys. We study the properties of galaxy groups and clusters identified using standard observational techniques and we study the relation of these groups to real virialised systems. Most features of CfA2N groups are reproduced quite well by both models with no obvious dependence on Omega_0. Redshift space correlations and pairwise velocities are also similar in the two cosmologies. The luminosity functions predicted by our galaxy formation models depend sensitively on the treatment of star formation and feedback. For the particular choices of Paper I they agree poorly with the CfA survey. To isolate the effect of this discrepancy on our mock redshift surveys, we modify galaxy luminosities in our simulations to reproduce the CfA luminosity function exactly. This adjustment improves agreement with the observed abundance of groups, which depends primarily on the galaxy luminosity density, but other statistics, connected more closely with the underlying mass distribution, remain unaffected. Regardless of the luminosity function adopted, modest differences with observation remain. These can be attributed to the presence of the ``Great Wall'' in the CfA2N. It is unclear whether the greater coherence of the real structure is a result of cosmic variance, given the relatively small region studied, or reflects a physical deficiency of the models.

Antonaldo Diaferio; Guinevere Kauffmann; Joerg M. Colberg; Simon D. M. White

1998-12-01T23:59:59.000Z

53

Distributed Generation Source Stiffness and Its Impact on Voltage Distortion  

Science Conference Proceedings (OSTI)

Distributed generators with loads that create high harmonics can cause excessive voltage distortion. This report's objective was to evaluate under controlled laboratory conditions voltage distortion resulting from application of nonlinear load for three different types of rotary generators and one inverter-based generator. Test results also were used to verify the analytical model for predicting voltage distortion from nonlinear load application.

2001-11-27T23:59:59.000Z

54

The Star Formation History and Stellar Assembly of High Redshift Galaxies  

E-Print Network (OSTI)

I discuss current observational constraints on the star-formation and stellar-assembly histories of galaxies at high redshifts. The data on massive galaxies at z2, and that their morphological configuration was in place soon thereafter. Spitzer Space Telescope 24 micron observations indicate that a substantial fraction of massive galaxies at z ~ 1.5-3 have high IR luminosities, suggesting they are rapidly forming stars, accreting material onto supermassive black holes, or both. I compare how observations of these IR-active phases in the histories of massive galaxies constrain current galaxy-formation models.

Casey Papovich

2006-11-02T23:59:59.000Z

55

Prediction of Part Distortion in Die Casting  

SciTech Connect

The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

R. Allen Miller

2005-03-30T23:59:59.000Z

56

The Visibility of Galactic Bars and Spiral Structure At High Redshifts  

E-Print Network (OSTI)

We investigate the visibility of galactic bars and spiral structure in the distant Universe by artificially redshifting 101 B-band CCD images of local spiral galaxies from the Ohio State University Bright Spiral Galaxy Survey. Our artificially redshifted images correspond to Hubble Space Telescope I-band observations of the local galaxy sample seen at z=0.7, with integration times matching those of both the very deep Northern Hubble Deep Field data, and the much shallower Flanking Field observations. The expected visibility of galactic bars is probed in two ways: (1) using traditional visual classification, and (2) by charting the changing shape of the galaxy distribution in "Hubble space", a quantitative two-parameter description of galactic structure that maps closely on to Hubble's original tuning fork. Both analyses suggest that over 2/3 of strongly barred luminous local spirals i.e. objects classified as SB in the Third Reference Catalog) would still be classified as strongly barred at z=0.7 in the Hubbl...

Van den Bergh, S; Whyte, L F; Merrifield, M R; Eskridge, P B; Frogel, J A; Pogge, R W; Bergh, Sidney van den; Abraham, Roberto G.; Whyte, Laura F.; Merrifield, Michael R.; Eskridge, Paul; Frogel, Jay A.; Pogge, Richard

2002-01-01T23:59:59.000Z

57

Redshift-Independent Distances to Type Ia Supernovae  

E-Print Network (OSTI)

We describe a procedure for accurately determining luminosity distances to Type Ia supernovae (SNe Ia) without knowledge of redshift. This procedure, which may be used as an extension of any of the various distance determination methods currently in use, is based on marginalizing over redshift, removing the requirement of knowing $z$ a priori. We demonstrate that the Hubble diagram scatter of distances measured with this technique is approximately equal to that of distances derived from conventional redshift-specific methods for a set of 60 nearby SNe Ia. This indicates that accurate distances for cosmological SNe Ia may be determined without the requirement of spectroscopic redshifts, which are typically the limiting factor for the number of SNe that modern surveys can collect. Removing this limitation would greatly increase the number of SNe for which current and future SN surveys will be able to accurately measure distance. The method may also be able to be used for high-$z$ SNe Ia to determine cosmological density parameters without redshift information.

Brian J. Barris; John L. Tonry

2004-08-04T23:59:59.000Z

58

Analysis of Harmonic Distortion Levels in Commercial Buildings  

Science Conference Proceedings (OSTI)

This case study describes harmonic distortion concerns for commercial buildings and presents a method for evaluating these concerns based on typical load characteristics.

2003-12-31T23:59:59.000Z

59

Lattice Distortion Formations by Low Energy Ar+ Bombardment of ...  

Science Conference Proceedings (OSTI)

The intensity distribution consists of two maxima, one from the distorted layer ... Deformation Behavior of Nanocrystalline Co Measured by High-energy X-ray ...

60

Spectral Emission of Moving Atom Exhibits always a Redshift  

E-Print Network (OSTI)

A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the spectral emission of a moving atom exhibits always a redshift which informs not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a portion of its internal energy on transiting to a lower-energy state which however has in a moving atom an additional energy gain; this results in a redshift in the emission frequency. Based on auxiliary experimental information and a scheme for de Broglie particle formation, we give a vigorous elucidation of the mechanism for deceleration radiation of atomic electron; the corresponding prediction of the redshift is in complete agreement with the Ives and Stilwell's experimental formula.

Zheng-Johansson, J X

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
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61

RedShift Systems Corporation | Open Energy Information  

Open Energy Info (EERE)

RedShift Systems Corporation RedShift Systems Corporation Jump to: navigation, search Name RedShift Systems Corporation Address 41 Second Avenue Place Burlington, Massachusetts Zip 01803 Sector Efficiency Product Thermal imaging systems for building efficiency tools, smart grid monitoring Website http://redshiftsystems.com/sit Coordinates 42.483819°, -71.222836° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.483819,"lon":-71.222836,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

62

Ice emission and the redshifts of submillimeter sources  

E-Print Network (OSTI)

Observations at submillimeter wavelengths have revealed a population of sources thought to be at relatively large redshifts. The position of the 850 $\\mu$m passband on the Rayleigh-Jeans portion of the Planck function leads to a maximum redshift estimate of $z\\sim$4.5 since sources will not retain their redshift independent brightness close to the peak of the Planck function and thus drop out of surveys. Here we review evidence that ice absorption is present in the spectra of local ultraluminous infrared galaxies which are often taken as analogs for the 850 $\\mu$m source population. We consider the implication of this absorption for ice induced spectral structure at far infrared wavelengths and present marginal astronomical evidence that amorphous ice may have a feature similar to crystalline ice near 150 $\\mu$m. Recent corroborative laboratory evidence is supportive of this conclusion. It is argued that early metal enrichment by pair instability SN may lead to a high ice content relative to refractory dust at high redshift and a fairly robust detection of ice emission in a $z=6.42$ quasar is presented. It is further shown that ice emission is needed to understand the 450 $\\mu$m sources observed in the GOODS-N field. We are thus encouraged to apply far infrared ice emission models to the available observations of HDF 850.1, the brightest submillimeter source in the {\\it Hubble Deep Field}. We suggest that a redshift as large as 13 may need to be considered for this source, nearly a factor of three above the usual top estimate. Inclusion of the possibility of far infrared ice emission in the spectral energy distributions of model sources generally broadens the range of redshifts to be considered for submillimeter sources compared to models without ice emission.

C. C. Dudley; M. Imanishi; P. R. Maloney

2008-02-12T23:59:59.000Z

63

Chemical Consequences of Heme Distortion and the Role of Heme Distortion in Signal Transduction of H-NOX Proteins  

E-Print Network (OSTI)

Chemical Consequences of Heme Distortion and the Role ofMatthew B. Francis Spring 2010 Chemical Consequences of Hemeby Charles Olea, Jr. Abstract Chemical Consequences of Heme

Olea, Jr., Charles

2010-01-01T23:59:59.000Z

64

Spectroscopic Identification of a Proto-Cluster at z=2.300: Environmental Dependence of Galaxy Properties at High Redshift  

E-Print Network (OSTI)

We have discovered a highly significant over-density of galaxies at z=2.300+/-0.015 in the course of a redshift survey designed to select star-forming galaxies in the redshift range z=2.3+/-0.4 in the field of the bright z=2.72 QSO HS1700+643. The structure has a redshift-space galaxy over-density of delta_g,z ~= 7 and an estimated matter over-density in real space of delta_m ~= 1.8, indicating that it will virialize by z~0 with a mass scale of ~= 1.4x10^15 M_sun, that of a rich galaxy cluster. Detailed modeling of the spectral energy distribution -- from the rest-far-UV to the rest-near-IR -- of the 72 spectroscopically confirmed galaxies in this field for which we have obtained K_s and Spitzer/IRAC photometry, allows for a first direct comparison of galaxy properties as a function of large-scale environment at high redshift. We find that galaxies in the proto-cluster environment have mean stellar masses and inferred ages that are ~2 times larger (at z=2.30) than identically UV-selected galaxies outside of the structure, and show that this is consistent with simple theoretical expectations for the acceleration of structure formation in a region that is over-dense on large scales by the observed amount. The proto-cluster environment contains a significant number of galaxies that already appear old, with large stellar masses (>10^11 M_sun), by z=2.3.

Charles C. Steidel; Kurt L. Adelberger; Alice E. Shapley; Dawn K. Erb; Naveen A. Reddy; Max Pettini

2005-02-21T23:59:59.000Z

65

On distorted probabilities and m-separable fuzzy measures  

Science Conference Proceedings (OSTI)

Fuzzy measures are used in conjunction with fuzzy integrals for aggregation. Their role in the aggregation is to permit the user to express the importance of the information sources (either criteria or experts). Due to the fact that fuzzy measures are ... Keywords: Distorted probabilities, Fuzzy measures, m-Dimensional distorted probabilities, m-Symmetric fuzzy measures

Yasuo Narukawa; Vicenç Torra

2011-12-01T23:59:59.000Z

66

High Redshift Galaxies in the Hubble Ultra Deep Field  

E-Print Network (OSTI)

My dissertation presents results from three recent investigations in the Hubble Ultra Deep Field (HUDF) focusing on understanding structural and physical properties of high redshift galaxies. Here I summarize results from these studies. This thesis work was conducted at Arizona State University under the guidance of Prof. Rogier Windhorst and Prof. Sangeeta Malhotra.

Nimish P. Hathi

2008-10-02T23:59:59.000Z

67

Achieving the Gaussian Rate-Distortion Function by Prediction  

E-Print Network (OSTI)

The "water-filling" solution for the quadratic rate-distortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain "test-channel" realization. We provide an alternative time-domain realization for the rate-distortion function, based on linear prediction. This solution has some interesting implications, including the optimality at all distortion levels of pre/post filtered vector-quantized differential pulse code modulation (DPCM), and a duality relationship with decision-feedback equalization (DFE) for inter-symbol interference (ISI) channels.

Zamir, Ram; Erez, Uri

2007-01-01T23:59:59.000Z

68

X-RAY ABSORPTION OF HIGH-REDSHIFT QUASARS  

SciTech Connect

The soft X-ray photoelectric absorption of high-z quasars has been known for two decades, but has no unambiguous astrophysical context. We construct the largest sample to date of 58 high-redshift quasars (z > 0.45) selected from the XMM-Newton archive based on a high photon count criterion (>1800). We measure the optical depth {tau} at 0.5 keV and find that 43% of the quasars show significant absorption. We aim to find which physical parameters of the quasars, e.g., redshift, radio luminosity, radio loudness, or X-ray luminosity, drive their observed absorption. We compare the absorption behavior with redshift with the pattern expected if the diffuse intergalactic medium (IGM) is responsible for the observed absorption. We also compare the absorption with a comparison sample of gamma-ray burst (GRB) X-ray afterglows. Although the z > 2 quasar opacity is consistent with diffuse IGM absorption, many intermediate-z (0.45 < z < 2) quasars are not sufficiently absorbed for this scenario, and are appreciably less absorbed than GRBs. Only 10/37 quasars at z < 2 are absorbed, and only 5/30 radio-quiet quasars are absorbed. We find a weak correlation between {tau} and z, and an even weaker correlation between {tau} and radio luminosity. These findings lead to the conclusion that although a diffuse IGM origin for the quasar absorption is unlikely, the optical depth does seem to increase with redshift, roughly as (1 + z){sup 2.2{+-}0.6}, tending to {tau} Almost-Equal-To 0.4 at high redshifts, similar to the high-z GRBs. This result can be explained by an ionized and clumpy IGM at z < 2, and a cold, diffuse IGM at higher redshift. If, conversely, the absorption occurs at the quasar, and owing to the steep L{sub x} {proportional_to}(1 + z){sup 7.1{+-}0.5} correlation in the present sample, the host column density scales as N{sub H}{proportional_to}L{sub x}{sup 0.7{+-}0.1}.

Eitan, Assaf; Behar, Ehud, E-mail: sassafe@tx.technion.ac.il, E-mail: behar@physics.technion.ac.il [Physics Department, Technion, Haifa 32000 (Israel)

2013-09-01T23:59:59.000Z

69

Fast distortion measurement using chord-length parameterisation within the vertex-based rate-distortion optimal shape coding framework  

E-Print Network (OSTI)

Existing vertex-based operational rate-distortion (ORD) optimal shape coding algorithms use the shortest absolute distance (SAD) or alternatively either the distortion band (DB) or tolerance band (TB) as their distortion measuring technique. Each approach however can lead to inaccurate distortion measurements, though these can be avoided by employing the accurate distortion measurement technique for shape coding (ADMSC). From a computational time 2 O N time for DB and TB for both polygon and B-spline based encoding, perspective, an N point contour requires () 2 while SAD and ADMSC incur order O ( N) time for polygonal encoding, but ( N) O complexity for B-spline based encoding, thereby rendering ORD optimal algorithms computationally inefficient. This paper presents a novel distortion measurement strategy based on chord-length parameterisation (DMCLP) of a boundary that incurs order O ( N) complexity for both polygon and B-spline based encoding, while preserving an analogous rate-distortion performance to the original ORD optimal shape coding algorithms, when it is embedded within the ORD framework. I.

Ferdous A. Sohel; Gour C. Karmakar; Laurence S. Dooley

2007-01-01T23:59:59.000Z

70

Preliminary mode distortion measurements on the Jefferson Lab IRFEL  

SciTech Connect

We previously reported analytical calculations of mirror distortion in a high power FEL with a near-concentric cavity. Naive assumptions about the FEL power vs. distortion led us to believe that mirror losses were much lower than expected. Recently we have directly measured the mode size and beam quality as a function of power using a resonator with a center wavelength of 5 microns. The resonator mirrors were calcium fluoride. This material exhibits a large amount of distortion for a given power but, due to the negative slope of refractive index v temperature, adds almost no optical phase distortion on the laser output. The mode in the cavity can thus be directly calculated from the measurements at the resonator output. The presence of angular jitter produced results inconsistent with cold cavity expectations. Removing the effects of the angular jitter produces results in reasonable agreement with analytical models assuming mirror losses comparable to the original expectations.

Stephen V. Benson; Joe Gubeli; Michelle D. Shinn

2001-08-01T23:59:59.000Z

71

Can Population III Stars at High Redshifts produce GRB's?  

E-Print Network (OSTI)

Gamma ray bursts are the most luminous physical phenomena in the universe, consisting of flashes of gamma rays that last from seconds to hours. There have been attempts to observe gamma ray bursts, for example, from population III stars of about 500 solar mass at high redshifts. Here we argue that collapse of such high mass stars does not lead to gamma ray burst as their core collapse temperatures are not sufficient to produce gamma rays, leading to GRBs.

C. Sivaram; Kenath Arun

2010-08-24T23:59:59.000Z

72

Powerful evidences for supporting the claim that gamma-ray burst redshifts are gravity-generated  

E-Print Network (OSTI)

At present, it is widely believed that the phenomenon of the gamma-ray burst redshift is cosmological origin. From a theoretical point of view, this redshift has either a cosmological or a cause that is related to gravity. However, the question of whether the gamma-ray burst redshift has a cosmological origin or not should be answerable in no uncertain terms because both the spectrum characteristics and the count distribution law arising from the two distinct settings are completely different. If the redshift of GRB is generated by gravity, then the afterglow spectrum will certainly contain both the gravitational redshits (containing emission and absorption feature) and Doppler absorption redshift, and hold a definite relation between the two redshifts. In this paper, we present nine direct and decisive evidences to show that the gamma-ray burst redshift is indeed generated by gravity of neutron stars in their merging process; in which, 114 GRBs' redshifts showed that the statistical count distribution law for the two kinds redshift is the same (with errors less than 1.5%), and 74 spectral line redshifts of two GRBs showed that the relation between the two kinds redshift is completely correct (with errors less than 0.0061%).

Fu-Gao Song

2008-05-22T23:59:59.000Z

73

The Effect of Inlet Flow Profile Distortion on Fan Performance  

Science Conference Proceedings (OSTI)

Performance tests on fans for utility and industrial applications are based on codes that expect a relatively uniform velocity profile at the fan inlet. Unfortunately, when fans scaled up from the ideal model fans are installed in actual utility and industrial applications, non-uniform or distorted flow patterns often occur at the inlet of the fan. This project sought to determine and, if possible, quantify the effect on fan performance of distorted inlet flow profiles. A second goal was to determine whe...

2010-02-22T23:59:59.000Z

74

Constraints on the correlation between QSO luminosity and host halo mass from high-redshift quasar clustering  

E-Print Network (OSTI)

Recent measurements of high-redshift QSO clustering from the Sloan Digital Sky Survey indicate that QSOs at z~4 have a bias b~14. We find that this extremely high clustering amplitude, combined with the corresponding space density, constrains the dispersion in the L-Mhalo relation to be less than 50% at 99% confidence for the most conservative case of a 100% duty cycle. This upper limit to the intrinsic dispersion provides as strong a constraint as current upper limits to the intrinsic dispersion in the local M_BH-sigma relation and the ratio of bolometric to Eddington luminosity of luminous QSOs.

Martin White; Paul Martini; J. D. Cohn

2007-11-26T23:59:59.000Z

75

The ESO Slice Project (ESP) galaxy redshift survey IV. A discussion of systematic biases in galaxy redshift determinations  

E-Print Network (OSTI)

We present a detailed discussion of the redshift errors associated to the ESO Slice Project measurements. For a subsample of 742 galaxies with redshifts determined both from the absorption lines (V_{abs}) and from the emission lines (V_{emi}), we find an average difference ~ +100$ km/s. We find that a similar effect is present in another, deeper redshift survey, the Durham/Anglo-Australian Telescope faint galaxy redshift survey, while is absent in surveys at brighter magnitude limits. We have investigated in detail many possible sources of such a discrepancy, and we can exclude possible zero-point shifts or calibration problems. We have detected and measured systematic velocity differences produced by the different templates used in the cross-correlation. We conclude that such differences can in principle explain the effect, but in this case the non-trivial implication would be that the best-fitting template does not necessarily give the best velocity estimate. As we do not have any a priori reason to select a template different from the best-fitting one, we did not apply any correction to the ESO Slice Project velocities. However, as for a small number of galaxies the effect is so large that it is likely to have a physical explanation, we have also taken into account the possibility that the discrepancy can be partly real: in this case, it might help to understand the role of gas outflows in the process of galaxy evolution. In view of the future large spectroscopic surveys, we stress the importance of using different templates and making them publicly available, in order to assess the amplitude of systematic effects, and to allow a direct comparison of different catalogues.

A. Cappi; G. Zamorani; E. Zucca; G. Vettolani; R. Merighi; M. Mignoli; G. M. Stirpe; C. Collins; L. Guzzo; G. Chincarini; D. Maccagni; C. Balkowski; V. Cayatte; S. Maurogordato; D. Proust; S. Bardelli; M. Ramella; R. Scaramella; A. Blanchard; H. MacGillivray

1998-05-19T23:59:59.000Z

76

 

NLE Websites -- All DOE Office Websites (Extended Search)

model of redshift space distortions worthy of BOSS data model of redshift space distortions worthy of BOSS data Beth Reid (LBNL) Abstract: Interest in using redshift space distortions (RSD) as a precise test of General Relativity on large scales has exploded in the last few years, but our theoretical models must be improved to match the statistical precision of current data. In this talk I will review of physics of redshift space distortions in configuration space and present projections for RSD constraints from the BOSS survey. While many recent studies focus on understanding dark matter clustering in redshift space, galaxies occupy special places in the universe: dark matter halos. Our model reproduces the complex dependence of redshift space clustering on halo bias seen in N-body simulations and is sufficiently precise to model the final BOSS data set on

77

PROBING PRE-GALACTIC METAL ENRICHMENT WITH HIGH-REDSHIFT GAMMA-RAY BURSTS  

SciTech Connect

We explore high-redshift gamma-ray bursts (GRBs) as promising tools to probe pre-galactic metal enrichment. We utilize the bright afterglow of a Population III (Pop III) GRB exploding in a primordial dwarf galaxy as a luminous background source, and calculate the strength of metal absorption lines that are imprinted by the first heavy elements in the intergalactic medium (IGM). To derive the GRB absorption line diagnostics, we use an existing highly resolved simulation of the formation of a first galaxy which is characterized by the onset of atomic hydrogen cooling in a halo with virial temperature {approx}> 10{sup 4} K. We explore the unusual circumburst environment inside the systems that hosted Pop III stars, modeling the density evolution with the self-similar solution for a champagne flow. For minihalos close to the cooling threshold, the circumburst density is roughly proportional to (1 + z) with values of about a few cm{sup -3}. In more massive halos, corresponding to the first galaxies, the density may be larger, n {approx}> 100 cm{sup -3}. The resulting afterglow fluxes are weakly dependent on redshift at a fixed observed time, and may be detectable with the James Webb Space Telescope and Very Large Array in the near-IR and radio wavebands, respectively, out to redshift z {approx}> 20. We predict that the maximum of the afterglow emission shifts from near-IR to millimeter bands with peak fluxes from mJy to Jy at different observed times. The metal absorption line signature is expected to be detectable in the near future. GRBs are ideal tools for probing the metal enrichment in the early IGM, due to their high luminosities and featureless power-law spectra. The metals in the first galaxies produced by the first supernova (SN) explosions are likely to reside in low-ionization stages (C II, O I, Si II and Fe II). We show that, if the afterglow can be observed sufficiently early, analysis of the metal lines may distinguish whether the first heavy elements were produced in a pair-instability supernova or a core-collapse (Type II) SN, thus constraining the initial mass function of the first stars.

Wang, F. Y.; Dai, Z. G. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Bromm, Volker [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Greif, Thomas H. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, D-85740 Garching bei Muenchen (Germany); Stacy, Athena [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Loeb, Abraham [Astronomy Department, Harvard University, 60 Garden St., Cambridge, MA 02138 (United States); Cheng, K. S. [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

2012-11-20T23:59:59.000Z

78

Approximate Coulomb distortion effects in (e,e'p) reactions  

E-Print Network (OSTI)

In this paper we apply a well-tested approximation of electron Coulomb distortion effects to the exclusive reaction (e,e'p) in the quasielastic region. We compare the approximate treatment of Coulomb distortion effects to the exact distorted wave Born approximation evaluated by means of partial wave analysis to gauge the quality of our approximate treatment. We show that the approximate M\\"oller potential has a plane-wave-like structure and hence permits the separation of the cross section into five terms which depend on bilinear products of transforms of the transition four current elements. These transforms reduce to Fourier transforms when Coulomb distortion is not present, but become modified with the inclusion of Coulomb distortion. We investigate the application of the approximate formalism to a model of 208Pb(e,e'p) using Dirac-Hartree single particle wave functions for the ground state and relativistic optical model wave functions for the continuum proton. We show that it is still possible to extract, albeit with some approximation, the various structure functions from the experimentally measured data even for heavy nuclei.

K. S. Kim; L. E. Wright

2005-03-30T23:59:59.000Z

79

A Hydrodynamical Approach to CMB mu-distortions  

E-Print Network (OSTI)

Spectral distortion of the cosmic microwave background provides a unique opportunity to probe primordial perturbations on very small scales by performing large-scale measurements. We discuss in a systematic and pedagogic way all the relevant physical phenomena involved in the production and evolution of the mu-type spectral distortion. Our main results agree with previous estimates (in particular we show that a recently found factor of 3/4 arises from relativistic corrections to the wave energy). We also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon loading and photon heat conduction. Finally we calculate the transfer function for mu-distortions between the end of the mu-era and now.

Enrico Pajer; Matias Zaldarriaga

2012-06-20T23:59:59.000Z

80

DETERMINING THE LUMINOSITY FUNCTION OF SWIFT LONG GAMMA-RAY BURSTS WITH PSEUDO-REDSHIFTS  

SciTech Connect

The determination of the luminosity function (LF) of gamma-ray bursts (GRBs) is an important role for the cosmological applications of the GRBs, which, however, is seriously hindered by some selection effects due to redshift measurements. In order to avoid these selection effects, we suggest calculating pseudo-redshifts for Swift GRBs according to the empirical L-E{sub p} relationship. Here, such a L-E{sub p} relationship is determined by reconciling the distributions of pseudo- and real redshifts of redshift-known GRBs. The values of E{sub p} taken from Butler's GRB catalog are estimated with Bayesian statistics rather than observed. Using the GRB sample with pseudo-redshifts of a relatively large number, we fit the redshift-resolved luminosity distributions of the GRBs with a broken-power-law LF. The fitting results suggest that the LF could evolve with redshift by a redshift-dependent break luminosity, e.g., L{sub b} = 1.2 Multiplication-Sign 10{sup 51}(1 + z){sup 2} erg s{sup -1}. The low- and high-luminosity indices are constrained to 0.8 and 2.0, respectively. It is found that the proportional coefficient between the GRB event rate and the star formation rate should correspondingly decrease with increasing redshifts.

Tan Weiwei; Yu Yunwei [Institute of Astrophysics, Central China Normal University, Wuhan (China); Cao Xiaofeng, E-mail: yuyw@phy.ccnu.edu.cn [School of Physics, Huazhong University of Science and Technology, Wuhan (China)

2013-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Intracluster gas pressure, entropy injection and redshift evolution  

E-Print Network (OSTI)

We study the effect of entropy injection in the intracluster medium (ICM) in light of the recent observationally determined universal pressure profile of the ICM. Beginning with a power-law entropy profile that is expected in the absence of any feedback, we show that a simple universal prescription of entropy injection results in the final, observed universal pressure profile. This simple prescription has two components, one associated with an overall increase in entropy and another associated with injection in the central parts of the cluster. Importantly, both the components of entropy injection are needed to produce the final universal pressure profile. This is indicative of a need of both preheating the ICM as well {\\it in situ} AGN/SNe heating. We demonstrate the usefulness of the method by extending the calculations to clusters at high redshift, and predict redshift evolution of cluster scaling relations that can be tested against data. We show that the self-similar evolution of the universal pressure p...

Nath, Biman B

2011-01-01T23:59:59.000Z

82

The Rate of Type Ia Supernovae at High Redshift  

E-Print Network (OSTI)

We derive the rates of Type Ia supernovae (SNIa) over a wide range of redshifts using a complete sample from the IfA Deep Survey. This sample of more than 100 SNIa is the largest set ever collected from a single survey, and therefore uniquely powerful for a detailed supernova rate (SNR) calculation. Measurements of the SNR as a function of cosmological time offer a glimpse into the relationship between the star formation rate (SFR) and Type Ia SNR, and may provide evidence for the progenitor pathway. We observe a progressively increasing Type Ia SNR between redshifts z~0.3-0.8. The Type Ia SNR measurements are consistent with a short time delay (t~1 Gyr) with respect to the SFR, indicating a fairly prompt evolution of SNIa progenitor systems. We derive a best-fit value of SFR/SNR 580 h_70^(-2) M_solar/SNIa for the conversion factor between star formation and SNIa rates, as determined for a delay time of t~1 Gyr between the SFR and the Type Ia SNR. More complete measurements of the Type Ia SNR at z>1 are necessary to conclusively determine the SFR--SNR relationship and constrain SNIa evolutionary pathways.

Brian J. Barris; John L. Tonry

2005-09-22T23:59:59.000Z

83

From Nearby to High Redshift Compact Group of Galaxies  

E-Print Network (OSTI)

Nearby Compact Groups of Galaxies (CGs) are very complex systems, tracing their history is a challenge (e.g. Stephan's Quintet). The presence of a diffuse X-rays emission that often peaks in the center of CGs shows that CGs are bound structures, they show numerous signs of interaction but their lifetime in much longer than their crossing times. Hickson CGs clearly show different stages of evolution, from weakly interacting galaxies to merging systems. CGs infalling into clusters may provide a mechanism to form clusters at high redshifts (e.g. in A1367). Massive versions of today's CGs may have been the best candidate precursors of fossil groups. Do CGs mimic the high redshift universe? This is still an open question. Indeed, their high density and low velocity dispersion should induce a high interaction rate and fast merging, CGs are nevertheless long-lived structures. On the other hand, there is probably no (or a few) isolated CGs in the high z universe. CGs may fuel high z clusters, they may produce fossil ...

Amram, P; De Oliveira, C M; Plana, H; Epinat, B; Amram, Philippe; Balkowski, Chantal; Oliveira, Claudia Mendes de; Plana, Henri; Epinat, Benoit

2006-01-01T23:59:59.000Z

84

From Nearby to High Redshift Compact Group of Galaxies  

E-Print Network (OSTI)

Nearby Compact Groups of Galaxies (CGs) are very complex systems, tracing their history is a challenge (e.g. Stephan's Quintet). The presence of a diffuse X-rays emission that often peaks in the center of CGs shows that CGs are bound structures, they show numerous signs of interaction but their lifetime in much longer than their crossing times. Hickson CGs clearly show different stages of evolution, from weakly interacting galaxies to merging systems. CGs infalling into clusters may provide a mechanism to form clusters at high redshifts (e.g. in A1367). Massive versions of today's CGs may have been the best candidate precursors of fossil groups. Do CGs mimic the high redshift universe? This is still an open question. Indeed, their high density and low velocity dispersion should induce a high interaction rate and fast merging, CGs are nevertheless long-lived structures. On the other hand, there is probably no (or a few) isolated CGs in the high z universe. CGs may fuel high z clusters, they may produce fossil groups and fossil ellipticals. CGs at high z are difficult to detect and are still to be discovered. Interpretation of distant kinematics of galaxies may need nearby sample of galaxies to disentangle beam-smearing from evolutionary effects (e.g. HCG 31). Beam smearing effects may bias the Tully-Fisher relation (shifted towards lower M/L).

Philippe Amram; Chantal Balkowski; Claudia Mendes de Oliveira; Henri Plana; Benoit Epinat

2006-10-30T23:59:59.000Z

85

Exploring the infrared/radio correlation at high redshift  

E-Print Network (OSTI)

We have analysed the 24um properties of a radio-selected sample in the Subaru-XMM/Newton Deep Field in order to explore the behaviour of the FIR/radio relation at high redshifts. Statistically, the correlation is described by q24, the ratio between the observed flux densities at 24um and 1.4GHz, respectively. Using 24um data results in considerably more scatter in the correlation than previous work using data at 60-70um. Nevertheless, we do observe a steady correlation as a function of redshift, up to z~3.5, suggesting its validity back to primeval times. We find q24 = 0.30 +/- 0.56 for the observed and q24 = 0.71 +/- 0.47 for the k-corrected radio sample, based on sources with 300uJy 1mJy. The rest-frame U-B colours of the expected radio-excess population have redder distribution than those that follow the correlation. This is therefore a promising way to select obscured Type-2 AGN, with a radio loud nature, missed by deep X-ray observations. Spectroscopic follow-up of these sources is required to fully test this method.

Edo Ibar; Michele Cirasuolo; Rob Ivison; Philip Best; Ian Smail; Andy Biggs; Chris Simpson; Jim Dunlop; Omar Almaini; Ross McLure; Sebastien Foucaud; Steve Rawlings

2008-02-19T23:59:59.000Z

86

Distortion-aware scalable video streaming to multinetwork clients  

Science Conference Proceedings (OSTI)

We consider the problem of scalable video streaming from a server to multinetwork clients over heterogeneous access networks, with the goal of minimizing the distortion of the received videos. This problem has numerous applications including: 1) mobile ... Keywords: quality optimization, rate control, stream adaptation, video streaming

Nikolaos M. Freris, Cheng-Hsin Hsu, Jatinder Pal Singh, Xiaoqing Zhu

2013-04-01T23:59:59.000Z

87

Luminosity distance and redshift in the Szekeres inhomogeneous cosmological models  

E-Print Network (OSTI)

The Szekeres inhomogeneous models can be used to model the true lumpy universe that we observe. This family of exact solutions to Einstein's equations was originally derived with a general metric that has no symmetries. In this work, we develop and use a framework to integrate the angular diameter and luminosity distances in the general Szekeres models. We use the affine null geodesic equations in order to derive a set of first-order ordinary differential equations that can be integrated numerically to calculate the partial derivatives of the null vector components. These equations allow the integration in all generality of the distances in the Szekeres models and some examples are given. The redshift is determined from simultaneous integration of the null geodesic equations. This work does not assume spherical or axial symmetry, and the results will be useful for comparisons of the general Szekeres inhomogeneous models to current and future cosmological data.

Anthony Nwankwo; Mustapha Ishak; John Thompson

2010-05-17T23:59:59.000Z

88

RECONSTRUCTING REDSHIFT DISTRIBUTIONS WITH CROSS-CORRELATIONS: TESTS AND AN OPTIMIZED RECIPE  

SciTech Connect

Many of the cosmological tests to be performed by planned dark energy experiments will require extremely well-characterized photometric redshift measurements. Current estimates for cosmic shear are that the true mean redshift of the objects in each photo-z bin must be known to better than 0.002(1 + z), and the width of the bin must be known to {approx}0.003(1 + z) if errors in cosmological measurements are not to be degraded significantly. A conventional approach is to calibrate these photometric redshifts with large sets of spectroscopic redshifts. However, at the depths probed by Stage III surveys (such as DES), let alone Stage IV (LSST, JDEM, and Euclid), existing large redshift samples have all been highly (25%-60%) incomplete, with a strong dependence of success rate on both redshift and galaxy properties. A powerful alternative approach is to exploit the clustering of galaxies to perform photometric redshift calibrations. Measuring the two-point angular cross-correlation between objects in some photometric redshift bin and objects with known spectroscopic redshift, as a function of the spectroscopic z, allows the true redshift distribution of a photometric sample to be reconstructed in detail, even if it includes objects too faint for spectroscopy or if spectroscopic samples are highly incomplete. We test this technique using mock DEEP2 Galaxy Redshift survey light cones constructed from the Millennium Simulation semi-analytic galaxy catalogs. From this realistic test, which incorporates the effects of galaxy bias evolution and cosmic variance, we find that the true redshift distribution of a photometric sample can, in fact, be determined accurately with cross-correlation techniques. We also compare the empirical error in the reconstruction of redshift distributions to previous analytic predictions, finding that additional components must be included in error budgets to match the simulation results. This extra error contribution is small for surveys that sample large areas of sky (>{approx}10{sup 0}-100{sup 0}), but dominant for {approx}1 deg{sup 2} fields. We conclude by presenting a step-by-step, optimized recipe for reconstructing redshift distributions from cross-correlation information using standard correlation measurements.

Matthews, Daniel J.; Newman, Jeffrey A., E-mail: djm70@pitt.ed, E-mail: janewman@pitt.ed [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States)

2010-09-20T23:59:59.000Z

89

THE 2MASS REDSHIFT SURVEY-DESCRIPTION AND DATA RELEASE  

SciTech Connect

We present the results of the 2MASS Redshift Survey (2MRS), a ten-year project to map the full three-dimensional distribution of galaxies in the nearby universe. The Two Micron All Sky Survey (2MASS) was completed in 2003 and its final data products, including an extended source catalog (XSC), are available online. The 2MASS XSC contains nearly a million galaxies with K{sub s} {<=} 13.5 mag and is essentially complete and mostly unaffected by interstellar extinction and stellar confusion down to a galactic latitude of |b| = 5 Degree-Sign for bright galaxies. Near-infrared wavelengths are sensitive to the old stellar populations that dominate galaxy masses, making 2MASS an excellent starting point to study the distribution of matter in the nearby universe. We selected a sample of 44,599 2MASS galaxies with K{sub s} {<=} 11.75 mag and |b| {>=} 5 Degree-Sign ({>=}8 Degree-Sign toward the Galactic bulge) as the input catalog for our survey. We obtained spectroscopic observations for 11,000 galaxies and used previously obtained velocities for the remainder of the sample to generate a redshift catalog that is 97.6% complete to well-defined limits and covers 91% of the sky. This provides an unprecedented census of galaxy (baryonic mass) concentrations within 300 Mpc. Earlier versions of our survey have been used in a number of publications that have studied the bulk motion of the Local Group, mapped the density and peculiar velocity fields out to 50 h{sup -1} Mpc, detected galaxy groups, and estimated the values of several cosmological parameters. Additionally, we present morphological types for a nearly complete sub-sample of 20,860 galaxies with K{sub s} {<=} 11.25 mag and |b| {>=} 10 Degree-Sign .

Huchra, John P.; Berlind, Perry; Calkins, Michael; Falco, Emilio; Mink, Jessica D.; Tokarz, Susan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Macri, Lucas M. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station, TX 77843 (United States); Masters, Karen L. [Institute for Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Jarrett, Thomas H. [Infrared Processing and Analysis Center, California Institute of Technology, 770 S Wilson Ave., Pasadena, CA 91125 (United States); Crook, Aidan C. [Microsoft Corp., 1 Microsoft Way, Redmond, WA 98052 (United States); Cutri, Roc [SEPNet (South East Physics Network) (United Kingdom); Erdogdu, Pirin; Lahav, Ofer [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); George, Teddy [Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743 (United States); Hutcheson, Conrad M. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94309 (United States); Mader, Jeff [Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States); Martimbeau, Nathalie [Planetarium de Montreal, 1000 rue Saint-Jacques, Montreal, Quebec H3C 1G7 (Canada); Schneider, Stephen [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Skrutskie, Michael [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Westover, Michael, E-mail: lmacri@tamu.edu, E-mail: karen.masters@port.ac.uk [McKinsey and Co., 1420 Fifth Ave., Ste 3100, Seattle, WA 98101 (United States)

2012-04-01T23:59:59.000Z

90

High Redshift Gamma-Ray Bursts: Observational Signatures of Superconducting Cosmic Strings?  

E-Print Network (OSTI)

The high-redshift gamma-ray bursts (GRBs), GRBs 080913 and 090423, challenge the conventional GRB progenitor models by their short durations, typical for short GRBs, and their high energy releases, typical for long GRBs. Meanwhile, the GRB rate inferred from high-redshift GRBs also remarkably exceeds the prediction of the collapsar model, with an ordinary star formation history. We show that all these contradictions could be eliminated naturally, if we ascribe some high-redshift GRBs to electromagnetic bursts of superconducting cosmic strings. High-redshift GRBs could become a reasonable way to test the superconducting cosmic string model, because the event rate of cosmic string bursts increases rapidly with increasing redshifts, whereas the collapsar rate decreases.

K. S. Cheng; Yun-Wei Yu; T. Harko

2010-05-19T23:59:59.000Z

91

Measuring the Dark Matter Halo Mass of X-ray AGN at z~1 using photometric redshifts  

E-Print Network (OSTI)

Data from the AEGIS, COSMOS and ECDFS surveys are combined to infer the bias and dark matter halo mass of moderate luminosity [LX(2-10 keV) = 42.9 erg s-1] X-ray AGN at z~1 via their cross-correlation function with galaxies. In contrast to standard cross-correlation function estimators, we present a method that requires spectroscopy only for the AGN and uses photometric redshift probability distribution functions for galaxies to determine the projected real-space AGN/galaxy cross-correlation function. The estimated dark matter halo mass of X-ray AGN in the combined AEGIS, COSMOS and ECDFS fields is ~13h-1M_solar, in agreement with previous studies at similar redshift and luminosity ranges. Removing from the sample the 5 per cent of the AGN associated with X-ray selected groups results in a reduction by about 0.5 dex in the inferred AGN dark matter halo mass. The distribution of AGN in dark matter halo mass is therefore skewed and the bulk of the population lives in moderate mass haloes. This result favour col...

Mountrichas, G; Finoguenov, A; Erfanianfar, G; Cooper, M C; Coil, A L; Laird, E S; Nandra, K; Newman, J A

2012-01-01T23:59:59.000Z

92

A NEW POPULATION OF HIGH-REDSHIFT SHORT-DURATION GAMMA-RAY BURSTS E. Berger,1,2,3  

E-Print Network (OSTI)

A NEW POPULATION OF HIGH-REDSHIFT SHORT-DURATION GAMMA-RAY BURSTS E. Berger,1,2,3 D. B. Fox,4 P. A The redshift distribution of the short-duration gamma-ray bursts (GRBs) is a crucial, but currently fragmentary rays: bursts Online material: color figures 1. INTRODUCTION The redshift distribution of the short

Sheppard, Scott S.

93

An Improved Technique for Increasing the Accuracy of Photometrically Determined Redshifts for ___Blended___ Galaxies  

SciTech Connect

The redshift of a galaxy can be determined by one of two methods; photometric or spectroscopic. Photometric is a term for any redshift determination made using the magnitudes of light in different filters. Spectroscopic redshifts are determined by measuring the absorption spectra of the object then determining the difference in wavelength between the 'standard' absorption lines and the measured ones, making it the most accurate of the two methods. The data for this research was collected from SDSS DR8 and then separated into blended and non-blended galaxy sets; the definition of 'blended' is discussed in the Introduction section. The current SDSS photometric redshift determination method does not discriminate between blended and non-blended data when it determines the photometric redshift of a given galaxy. The focus of this research was to utilize machine learning techniques to determine if a considerably more accurate photometric redshift determination method could be found, for the case of the blended and non-blended data being treated separately. The results show a reduction of 0.00496 in the RMS error of photometric redshift determinations for blended galaxies and a more significant reduction of 0.00827 for non-blended galaxies, illustrated in Table 2.

Parker, Ashley Marie; /Marietta Coll. /SLAC

2012-08-24T23:59:59.000Z

94

Distortion analysis of analog multiplier circuits using two-dimensional integral nonlinear function  

Science Conference Proceedings (OSTI)

This work presents an adaptation to the definition of the Integral Nonlinear Function (INLF) for distortion analysis of analog multipliers. Up to this time distortion in two-input multipliers has been evaluated by applying a constant signal to one of ... Keywords: CMOS multipliers, analog multipliers, distortion

Luciano A. de Lacerda; Edson P. Santana; Cleber Vinícius A. de Almeida; Ana Isabela A. Cunha

2009-08-01T23:59:59.000Z

95

The ESO Slice Project (ESP) galaxy redshift survey: III. The Sample  

E-Print Network (OSTI)

The ESO Slice Project (ESP) is a galaxy redshift survey extending over about 23 square degrees, in a region near the South Galactic Pole. The survey is ~85% complete to the limiting magnitude b_J=19.4 and consists of 3342 galaxies with redshift determination. The ESP survey is intermediate between shallow, wide angle samples and very deep, one-dimensional pencil beams; the spanned volume is ~ 5 x 10^4 Mpc^3 at the sensitivity peak (z ~ 0.1). In this paper we present the description of the observations and of the data reduction, the ESP redshift catalogue and the analysis of the quality of the velocity determinations.

G. Vettolani; E. Zucca; R. Merighi; M. Mignoli; D. Proust; G. Zamorani; A. Cappi; L. Guzzo; D. Maccagni; M. Ramella; G. M. Stirpe; A. Blanchard; V. Cayatte; C. Collins; H. MacGillivray; S. Maurogordato; R. Scaramella; C. Balkowski; G. Chincarini; P. Felenbok

1998-05-14T23:59:59.000Z

96

Caltech Faint Galaxy Redshift Survey VIII: Analysis for the Field J0053+1234  

E-Print Network (OSTI)

The results of a spectroscopic investigation of a complete sample of objects with $K_s 1.5$, and the galaxies in such groups appear to be coeval and to show little sign of ongoing star formation. The galaxies outside the redshift peaks are also clustered, albeit more weakly, are less luminous and more frequently exhibit strong emission lines. These ``isolated'' galaxies therefore appear, on average, to form stars at later epochs than the strongly clustered galaxies. The galaxy SEDs derived from our $UBVRIK$ photometry are also very closely correlated with the galaxy spectral types and luminosities. These results have strong implications for the analysis of redshift surveys at intermediate redshift.

Judith G. Cohen; Roger Blandford; David W. Hogg; Michael A. Pahre; Patrick L. Shopbell

1998-09-05T23:59:59.000Z

97

Redshifted 21-cm Signals in the Dark Ages  

E-Print Network (OSTI)

We have carried out semianalytic simulations to build redshifted 21-cm maps in the dark ages. An entropy-floor model is adopted for planting protogalaxies in simulated minihaloes. The model allocates gas quantities such as baryonic mass and temperature to every $N$-body particle and extensively exploits the particle nature of the data in the subsequent analysis. We have found that the number density of simulated minihaloes in the early universe is well described by the Sheth & Tormen function and consequently the signal powers of simulated minihaloes are far greater than the Press & Schechter prediction presented by Furlanetto (2006b). Even though the matter power spectrum measured in the halo particles at $z=15$ is about an order of magnitude smaller than the intergalactic medium (IGM), the 21-cm signal fluctuations of haloes are, to the contrary, one order of magnitude higher than the embedding adiabatic IGM on scales, $k\\lesssim 10 h{\\rm Mpc}^{-1}$. But their spectral shapes are almost same to each...

Kim, Juhan

2009-01-01T23:59:59.000Z

98

Searching for new OH megamasers out to redshifts z>1  

E-Print Network (OSTI)

We have carried out a search for 18-cm OH megamaser (OHM) emission with the Green Bank Telescope. The targeted galaxies comprise a sample of 121 ULIRGs at 0.090.25. Nine new detections of OHMs are reported, all at redshifts z 10^3 L_sun) for 26% of the sample, and extremely bright OHM emission (L_OH > 10^4 L_sun) for 73% of the sample. Losses from RFI result in the OHM detection fraction being significantly lower than expected for galaxies with L_IR >10^12 L_sun. The new OHM detections are used to calculate an updated OH luminosity function, with \\Phi[L]\\simL_OH^{-0.66}; this slope is in agreement with previous results. Non-detections of OHMs in the COSMOS field constrain the predicted sky density of OHMs; the results are consistent with a galaxy merger rate evolving as (1+z)^m, where m<6.

Willett, Kyle W

2012-01-01T23:59:59.000Z

99

Electricity Regulation in California and Input Market Distortions  

E-Print Network (OSTI)

We provide an analysis of the soft price cap regulation that occurred in California’s electricity market between December 2000 and June 2001. We demonstrate the incentive it created to distort the prices of electricity inputs. After introducing a theoretical model of the incentive, we present empirical data from two important input markets: pollution emissions permits and natural gas. We find substantial evidence that generators manipulated these costs in a way that allowed them to justify bids in excess of the price cap and earn higher rents than they could otherwise. Our analysis suggests that the potential benefits of soft price cap regulation were likely undone by such behavior. 1

Mark R. Jacobsen; Azeem M. Shaikh

2004-01-01T23:59:59.000Z

100

Optical distortions in electron/positron storage rings  

SciTech Connect

We have studied the optical distortions in the PEP electron/positron storage ring for various optical configurations using the computer programs DIMAT, HARMON, PATRICIA, and TURTLE. The results are shown graphically by tracing several thousand trajectories from one interaction region to the next using TURTLE and by tracing a few selected rays several hundred turns using the programs DIMAT and PATRICIA. The results show an interesting correlation between the calculated optical cleanliness of a particular lattice configuration and the observed operating characteristics of the machine.

Brown, K.L.; Donald, M.; Servranckx, R.

1983-01-01T23:59:59.000Z

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101

Mining the SDSS archive. I. Photometric redshifts in the nearby universe  

E-Print Network (OSTI)

We present a supervised neural network approach to the determination of photometric redshifts. The method was tuned to match the characteristics of the Sloan Digital Sky Survey and it exploits the spectroscopic redshifts provided by this unique survey. In order to train, validate and test the networks we used two galaxy samples drawn from the SDSS spectroscopic dataset: the general galaxy sample (GG) and the luminous red galaxies subsample (LRG). The method consists of a two steps approach. In the first step, objects are classified in nearby (ztrained on objects belonging to the two redshift ranges. Using a standard MLP operated in a Bayesian framework, the optimal architectures were found to require 1 hidden layer of 24 (24) and 24 (25) neurons for the GG (LRG) sample. The presence of systematic deviations was then corrected by interpolating the resulting redshifts. The final results on the GG dataset give a r...

Raffaele, D A; Giuseppe, L; Massimo, B; Maurizio, P; Elisabetta, D F; Roberto, T; Antonino, Staiano; Giuseppe, Longo; Massimo, Brescia; Maurizio, Paolillo; Elisabetta, De Filippis; Roberto, Tagliaferri

2007-01-01T23:59:59.000Z

102

Comment on "The Cosmic Time in Terms of the Redshift", by Carmeli et al  

E-Print Network (OSTI)

The time-redshift relation of Carmeli et al. differs from that of the standard flat LambdaCDM model by more than 500 million years for 1 < z < 4.5.

Alan Macdonald

2006-06-08T23:59:59.000Z

103

Probing the epoch of reionization with redshifted 21 cm HI emission  

E-Print Network (OSTI)

Emission and absorption features in the spectrum of the diffuse radio background below 200 MHz due to the 21 cm hyperfine transition line of neutral hydrogen gas in the high redshift intergalactic medium offer a new and ...

Bowman, Judd D. (Judd David)

2007-01-01T23:59:59.000Z

104

The clustering of intermediate redshift quasars as measured by the Baryon Oscillation Spectroscopic Survey  

E-Print Network (OSTI)

We measure the quasar two-point correlation function over the redshift range 2.2~10^{12}Msun/h with a duty cycle for the quasar activity of 1 per cent.

White, Martin; Ross, Nicholas P; Schlegel, David J; Hennawi, Joseph F; Shen, Yue; McGreer, Ian; Strauss, Michael A; Bolton, Adam S; Bovy, Jo; Fan, X; Miralda-Escude, Jordi; Palanque-Delabrouille, N; Paris, I; Petitjean, P; Schneider, D P; Viel, M; Weinberg, David H; Yeche, Ch; Zehavi, I; Pan, K; Snedden, S; Bizyaev, D; Brewington, H; Brinkman, J; Malanushenko, V; Malanushenko, E; Oravetz, D; Simmons, A; Sheldon, A; Weaver, Benjamin A

2012-01-01T23:59:59.000Z

105

The Extremely Red Objects Found Thus Far in the Caltech Faint Galaxy Redshift Survey  

E-Print Network (OSTI)

We discuss the very red objects found in the first field of the Caltech Faint Galaxy Redshift Survey, for which the observations and analysis are now complete. In this field, which is 15 arcmin$^2$ and at J005325+1234 there are 195 objects with $K_s < 20$ mag, of which 84% have redshifts. The sample includes 24 spectroscopically confirmed Galactic stars, 136 galaxies, three AGNs, and 32 objects without redshifts. About 10% of the sample has $(R-K) \\ge 5$ mag. Four of these objects have redshifts, with $0.78 \\le z \\le 1.23$. Three of these are based on absorption features in the mid-UV, while the lowest redshift object shows the standard features near 4000\\AA. Many of the objects still without redshifts have been observed spectroscopically, and no emission lines were seen in their spectra. We believe they are galaxies with $z \\sim 1 - 1.5$ that are red due to their age and stellar content and not to some large amount of internal reddening from dust. Among the many other results from this survey of interest here is a determination of the median extinction in the mid-UV for objects with strong emission line spectra at $z \\sim 1 - 1.3$. The result is extinction by a factor of $\\sim$2 at 2400\\AA.

Judith G. Cohen; David W. Hogg; Roger Blandford; Michael A. Pahre; Patrick L. Shopbell

1998-08-30T23:59:59.000Z

106

Power Spectrum Analysis of the ESP Galaxy Redshift Survey  

E-Print Network (OSTI)

We measure the power spectrum of the galaxy distribution in the ESO Slice Project (ESP) galaxy redshift survey. We develope a technique to describe the survey window function analytically, and then deconvolve it from the measured power spectrum using a variant of the Lucy method. We test the whole deconvolution procedure on ESP mock catalogues drawn from large N-body simulations, and find that it is reliable for recovering the correct amplitude and shape of $P(k)$ at $k> 0.065 h$ Mpc$^{-1}$. In general, the technique is applicable to any survey composed by a collection of circular fields with arbitrary pattern on the sky, as typical of surveys based on fibre spectrographs. The estimated power spectrum has a well-defined power-law shape $k^n$ with $n\\simeq -2.2$ for $k\\ge 0.2 h$ Mpc$^{-1}$, and a smooth bend to a flatter shape ($n\\simeq -1.6$) for smaller $k$'s. The smallest wavenumber, where a meaningful reconstruction can be performed ($k\\sim 0.06 h$ Mpc$^{-1}$), does not allow us to explore the range of scales where other power spectra seem to show a flattening and hints for a turnover. We also find, by direct comparison of the Fourier transforms, that the estimate of the two-point correlation function $\\xi(s)$ is much less sensitive to the effect of a problematic window function as that of the ESP, than the power spectrum. Comparison to other surveys shows an excellent agreement with estimates from blue-selected surveys. In particular, the ESP power spectrum is virtually indistinguishable from that of the Durham-UKST survey over the common range of $k$'s, an indirect confirmation of the quality of the deconvolution technique applied.

E. Carretti; C. Bertoni; A. Messina; E. Zucca; L. Guzzo

2000-07-02T23:59:59.000Z

107

Atomistic Simulations of Grain Boundary Associated Distortion in ...  

Science Conference Proceedings (OSTI)

... analysis provides a complete three-dimensional reciprocal space map of the grain ... Imaging: Case Studies in Alloys for Aerospace Propulsion Applications.

108

Mining the SDSS archive. I. Photometric redshifts in the nearby universe  

E-Print Network (OSTI)

We present a supervised neural network approach to the determination of photometric redshifts. The method was tuned to match the characteristics of the Sloan Digital Sky Survey and it exploits the spectroscopic redshifts provided by this unique survey. In order to train, validate and test the networks we used two galaxy samples drawn from the SDSS spectroscopic dataset: the general galaxy sample (GG) and the luminous red galaxies subsample (LRG). The method consists of a two steps approach. In the first step, objects are classified in nearby (ztrained on objects belonging to the two redshift ranges. Using a standard MLP operated in a Bayesian framework, the optimal architectures were found to require 1 hidden layer of 24 (24) and 24 (25) neurons for the GG (LRG) sample. The presence of systematic deviations was then corrected by interpolating the resulting redshifts. The final results on the GG dataset give a robust sigma_z = 0.0208 over the redshift range [0.01, 0.48] and sigma_z = 0.0197 and sigma_z = 0.0238 for the nearby and distant samples respectively. For the LRG subsample we find a robust sigma_z = 0.0164 over the whole range, and sigma_z = 0.0160, sigma_z = 0.0183 for the nearby and distant samples respectively. After training, the networks have been applied to all objects in the SDSS Table GALAXY matching the same selection criteria adopted to build the base of knowledge, and photometric redshifts for ca. 30 million galaxies having z<0.5 were derived. A catalogue containing photometric redshifts for the LRG subsample was also produced.

D'Abrusco Raffaele; Staiano Antonino; Longo Giuseppe; Brescia Massimo; Paolillo Maurizio; De Filippis Elisabetta; Tagliaferri Roberto

2007-03-06T23:59:59.000Z

109

Numerical Modeling Study and Assessment of PWR Fuel Rod and Assembly Distortion  

Science Conference Proceedings (OSTI)

Fuel assembly and rod distortion experienced in pressurized water reactors (PWRs) result in numerous operational challenges to plant operators such as mechanical interference between distorted assembly and control rods, difficulties in unloading and reloading cores during outages, and possibly anomalous fuel performance due to atypical water gaps. Therefore, an improved understanding of the various parameters contributing to distortion is important in order to manage or otherwise eliminate these ...

2012-11-30T23:59:59.000Z

110

Platek Spaces  

Science Conference Proceedings (OSTI)

The aim of this work is to axiomatize and enhance the recursion theory on monotonic hierarchies of operative spaces developed in [1]. This is to be accomplished by employing a special new variety of operative spaces called Platek spaces. The original ... Keywords: Platek spaces, combinatory algebra, computability, generalised recursion theory, lightface recursion

Lyubomir Ivanov

2000-08-01T23:59:59.000Z

111

Platek Spaces  

Science Conference Proceedings (OSTI)

The aim of this work is to axiomatize and enhance the recursion theory on monotonic hierarchies of operative spaces developed in [1]. This is to be accomplished by employing a special new variety of operative spaces called Platek spaces. The original ... Keywords: Platek spaces, combinatory algebra, computability, generalised recursion theory, lightface recursion

Lyubomir Ivanov

2000-01-01T23:59:59.000Z

112

Red-Shift Distribution of Gamma-ray Bursts and Their Progenitors  

E-Print Network (OSTI)

Gamma ray bursts have been divided into two classes, long-soft gamma ray burst and short-hard gamma ray burst according to the bimodal distribution in duration time. Due to the harder spectrum and the lack of afterglows of short-hard bursts in optical and radio observations, different progenitors for short-hard bursts and long-soft bursts have been suggested. Based on the X-ray afterglow observation and the cumulative red-shift distribution of short-hard bursts, Nakar et al. (2006) found that the progenitors of short-hard bursts are consistent with old populations, such as mergers of binary neutron stars. Recently, the existence of two subclasses in long-soft bursts has been suggested after considering multiple characteristics of gamma-ray bursts, including fluences and the duration time. In this work, we extended the analysis of cumulative red-shift distribution to two possible subclasses in L-GRBs. We found that two possible subclass GRBs show different red-shift distributions, especially for red-shifts z > 1. Our results indicate that the accumulative red-shift distribution can be used as a tool to constrain the progenitor characteristics of possible subclasses in L-GRBs.

Soomin Jeong; Chang-Hwan Lee

2007-10-08T23:59:59.000Z

113

Studying High Redshift Star Forming Galaxies at Centimeter and Millimeter Wavelengths  

E-Print Network (OSTI)

We discuss various aspects of centimeter and millimeter wavelength continuum and line observations of high redshift star forming galaxies. Perhaps the most important lesson is that sensitive observations at submm through cm wavelengths reveal a population of active star forming galaxies at high redshift which are unseen in deep optical surveys due to dust obscuration. Current models suggest that this population represents the formation of the spheroidal components of galaxies at z between 2 and 5, constituting about half of the total amount of cosmic star formation from the big bang to the present. High resolution imaging at cm wavelengths provides sub-arcsecond astrometry, and can be used to search for gravitational lensing and/or for the presence of an AGN. Radio continuum observations provide unique information on the magnetic fields in early galaxies, and give a gross indication of the star formation rate, while the radio-to-submm spectral index provides a rough indication of source redshift. Low J transitions of CO are redshifted into the cm bands for z > 2, allowing for sensitive searches for CO emission over large volumes at high redshift. We present recent results from the Very Large Array (VLA), and from the new 230 GHz MPIfR bolometer array at the IRAM 30m telescope. A wide field survey with the bolometer array indicates a cut-off in the source distribution function at FIR luminosities > 3e12 L_sun. Lastly, we summarize the scientific promise of the New VLA.

C. L. Carilli; K. M. Menten; M. S. Yun; F. Bertoldi; F. Owen; A. Dey

1999-07-30T23:59:59.000Z

114

How robust are the constraints on cosmology and galaxy evolution from the lens-redshift test?  

E-Print Network (OSTI)

The redshift distribution of galaxy lenses in known gravitational lens systems provides a powerful test that can potentially discriminate amongst cosmological models. However, applications of this elegant test have been curtailed by two factors: our ignorance of how galaxies evolve with redshift, and the absence of methods to deal with the effect of incomplete information in lensing systems. In this paper, we investigate both issues in detail. We explore how to extract the properties of evolving galaxies, assuming that the cosmology is well determined by other techniques. We propose a new nested Monte Carlo method to quantify the effects of incomplete data. We apply the lens-redshift test to an improved sample of seventy lens systems derived from recent observations, primarily from the SDSS, SLACS and the CLASS surveys. We find that the limiting factor in applying the lens-redshift test derives from poor statistics, including incomplete information samples, and biased sampling. Many lenses that uniformly sample the underlying true image separation distribution will be needed to use this test as a complementary method to measure the value of the cosmological constant or the properties of evolving galaxies. Planned future surveys by missions like the SNAP satellite or LSST are likely to usher in a new era for strong lensing studies that utilize this test. With expected catalogues of thousands of new strong lenses, the lens-redshift test could offer a powerful tool to probe cosmology as well as galaxy evolution.

Pedro R. Capelo; Priyamvada Natarajan

2007-05-22T23:59:59.000Z

115

Evaluation of the Distortion of a Hydro Turbine Blade during Heat ...  

Science Conference Proceedings (OSTI)

Presentation Title, Evaluation of the Distortion of a Hydro Turbine Blade during Heat Treatment Process. Author(s), Jinwu Kang. On-Site Speaker (Planned) ...

116

The environments of intermediate-redshift QSOs: 0.3 < z < 0.7  

E-Print Network (OSTI)

An angular correlation of low significance (2 sigma) is observed between 0.3 0.5 QSOs. After converting to an excess of galaxies physically associated with the QSO, this lack of strong correlation is shown to be consistent with the clustering of normal galaxies at the same moderate redshifts. Combined with previous observations, these results imply that the environments of radio-quiet QSOs do not undergo significant evolution with respect to the galaxy population over a wide range of redshifts (0 < z < 1.5). This is in marked contrast to the rapid increase in the richness of the environments associated with radio-loud QSOs over the same redshift range.

R. J. Smith; B. J. Boyle; S. J. Maddox

1999-11-22T23:59:59.000Z

117

Abundances at High Redshifts: the Chemical Enrichment History of Damped Lyman-alpha Galaxies  

E-Print Network (OSTI)

Damped Lyman-alpha absorption systems found in the spectra of high redshift quasars are believed to trace the interstellar gas in high redshift galaxies. In this paper, we study the elemental abundances of C, N, O, Al, Si, S, Cr, Mn, Fe, Ni, and Zn in a sample of 14 damped Lyman-alpha systems using high quality echelle spectra of quasars obtained with the 10m Keck telescope. These abundances are combined with similar measurements in the literature in order to investigate the chemical evolution of damped Lyman-alpha galaxies in the redshift range 0.7nature of the star formation process in damped Lyman-alpha galaxies, and the nature of damped Lyman-alpha galaxies themselves.

Limin Lu; Wallace L. W. Sargent; Thomas A. Barlow

1996-06-07T23:59:59.000Z

118

The Zurich Extragalactic Bayesian Redshift Analyzer (ZEBRA), version 1.0 -- User manual  

E-Print Network (OSTI)

ZEBRA, the Zurich Extragalactic Bayesian Redshift Analyzer, is a tool for estimating redshifts and template types of galaxies using medium- and broad-band photometric data. ZEBRA employs novel techniques within the template-fitting approach to produce high-quality Maximum-Likelihood and Bayesian redshift estimates. This manuscript serves as a user guide to ZEBRA. It explains how to use ZEBRA, specifies input and output formats, and gives a short account of the available options. ZEBRA is a free and open-source software distributed under the GNU Public License 3 and available at http://www.exp-astro.phys.ethz.ch/ZEBRA . Several upgrades are currently being implemented in ZEBRA. An updated documentation will be provided at each new release. Any problems, comments and suggestions on the code and the manual should be sent via e-mail to zebra@phys.ethz.ch.

R. Feldmann; C. M. Carollo; C. Porciani; S. J. Lilly; P. Oesch

2008-01-21T23:59:59.000Z

119

The fate of high redshift massive compact galaxies in dense environments  

SciTech Connect

Massive compact galaxies seem to be more common at high redshift than in the local universe, especially in denser environments. To investigate the fate of such massive galaxies identified at z {approx} 2 we analyse the evolution of their properties in three cosmological hydrodynamical simulations that form virialized galaxy groups of mass {approx} 10{sup 13} M{sub {circle_dot}} hosting a central massive elliptical/S0 galaxy by redshift zero. We find that at redshift {approx} 2 the population of galaxies with M{sub *} > 2 x 10{sup 10} M{sub {circle_dot}} is diverse in terms of mass, velocity dispersion, star formation and effective radius, containing both very compact and relatively extended objects. In each simulation all the compact satellite galaxies have merged into the central galaxy by redshift 0 (with the exception of one simulation where one of such satellite galaxy survives). Satellites of similar mass at z = 0 are all less compact than their high redshift counterparts. They form later than the galaxies in the z = 2 sample and enter the group potential at z < 1, when dynamical friction times are longer than the Hubble time. Also, by z = 0 the central galaxies have increased substantially their characteristic radius via a combination of in situ star formation and mergers. Hence in a group environment descendants of compact galaxies either evolve towards larger sizes or they disappear before the present time as a result of the environment in which they evolve. Since the group-sized halos that we consider are representative of dense environments in the {Lambda}CDM cosmology, we conclude that the majority of high redshift compact massive galaxies do not survive until today as a result of the environment.

Kaufmann, Tobias; /Zurich, ETH; Mayer, Lucio; /Zurich U.; Carollo, Marcella; /Zurich, ETH; Feldmann, Robert; /Fermilab /Chicago U., KICP

2012-01-01T23:59:59.000Z

120

Vertical displacement of the storage ring floor due to building distortion in the Photon Factory  

Science Conference Proceedings (OSTI)

The Light Source Building of the Photon Factory was found to distort so much as to induce the displacement of magnets in the storage ring. This resulted in drifting of the beam orbit. It was considered that the building was distorted by the variations of thermal stress

Tomotaro Katsura; Yutaka Fujita

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Computer correction of turbulent distortions of image of extended objects on near-Earth paths  

Science Conference Proceedings (OSTI)

An algorithm of computer-based correction of images of extended objects distorted by turbulent atmosphere is developed. The method of computer correction is used to correct a distorted image of an extended object on a horizontal 2300-m-long observation path. The angular size of the corrected-image region was 15'. (image processing)

Averin, A P; Morozov, Yu B; Pryanichkov, V S; Tyapin, V V [Federal State Unitary Enterprise 'I.S.Kos'minov State Scientific-Research Test Laser Centre of Russian Federation 'Raduga' (Russian Federation)

2011-05-31T23:59:59.000Z

122

Virtually distortion-free imaging system for large field, high resolution lithography  

DOE Patents (OSTI)

Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position.

Hawryluk, Andrew M. (Modesto, CA); Ceglio, Natale M. (Livermore, CA)

1993-01-01T23:59:59.000Z

123

Spectroscopic confirmation of a redshift 1.55 supernova host galaxy from the Subaru Deep Field Supernova Survey  

E-Print Network (OSTI)

The Subaru Deep Field (SDF) Supernova Survey discovered 10 Type Ia supernovae (SNe Ia) in the redshift range $1.5redshifts of the host galaxies. However, photometric redshifts might be biased, and the SN sample could be contaminated by active galactic nuclei (AGNs). Unfortunately, measuring spectroscopic redshifts of galaxies in the "redshift desert" 1.5 < z < 2.0 is hard because any prominent emission lines get shifted out of the optical and into the near infrared. Here we report the first robust redshift measurement and classification of hSDF0705.25, an SDF SN Ia host galaxy. Using the X-shooter spectrograph on the Very Large Telescope, we measure a spectroscopic redshift of 1.5456 +/- 0.0003, consistent with its photometric redshift of 1.552 +/- 0.018. From the strong emission-line spectrum we are able to rule out AGN activity and show that the SN host galaxy is a low-metallicity, star-burst dwarf galaxy, similar to typical SN Ia hosts at lower red...

Frederiksen, Teddy F; Hjorth, Jens; Maoz, Dan; Poznanski, Dovi

2012-01-01T23:59:59.000Z

124

Supernova rates from the Southern inTermediate Redshift ESO Supernova Search (STRESS)  

E-Print Network (OSTI)

To measure the supernova (SN) rates at intermediate redshift we performed the Southern inTermediate Redshift ESO Supernova Search (STRESS). Unlike most of the current high redshift SN searches, this survey was specifically designed to estimate the rate for both type Ia and core collapse (CC) SNe. We counted the SNe discovered in a selected galaxy sample measuring SN rate per unit blue band luminosity. Our analysis is based on a sample of ~43000 galaxies and on 25 spectroscopically confirmed SNe plus 64 selected SN candidates. Our approach is aimed at obtaining a direct comparison of the high redshift and local rates and at investigating the dependence of the rates on specific galaxy properties, most notably their colour. The type Ia SN rate, at mean redshift z=0.3, amounts to 0.22^{+0.10+0.16}_{-0.08 -0.14} h_{70}^2 SNu, while the CC SN rate, at z=0.21, is 0.82^{+0.31 +0.30}_{-0.24 -0.26} h_{70}^2 SNu. The quoted errors are the statistical and systematic uncertainties. With respect to local value, the CC SN rate at z=0.2 is higher by a factor of ~2 already at redshift, whereas the type Ia SN rate remains almost constant. This implies that a significant fraction of SN Ia progenitors has a lifetime longer than 2-3 Gyr. We also measured the SN rates in the red and blue galaxies and found that the SN Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe. SN rates per unit volume were found to be consistent with other measurements showing a steeper evolution with redshift for CC SNe with respect to SNe Ia. Finally we have exploited the link between star formation (SF) and SN rates to predict the evolutionary behaviour of the SN rates and compare it with the path indicated by observations.

M. T. Botticella; M. Riello; E. Cappellaro; S. Benetti; G. Altavilla; A. Pastorello; M. Turatto; L. Greggio; F. Patat; S. Valenti; L. Zampieri; A. Harutyunyan; G. Pignata; S. Taubenberger

2007-10-19T23:59:59.000Z

125

 

NLE Websites -- All DOE Office Websites (Extended Search)

function approach to redshift space distortions: N-body function approach to redshift space distortions: N-body simulations Teppei Okumura IEU, Institute for the Early Universe Abstract: Galaxy redshift surveys are one of the most powerful tools to probe cosmological models. Particularly measurement of redshift space distortions (RSD), caused by peculiar velocities of galaxies, offers an attractive method to directly probe the cosmic growth history of density perturbations. A distribution function approach where RSD can be written as a sum over density weighted velocity moment correlators has recently been developed. In this talk I present the redshift-space power spectrum based on this approach using N-body simulations and show that this formalism predicts the true power spectrum up to sufficiently small scales. Although

126

Non-equilibrium Lorentz gas on a curved space  

E-Print Network (OSTI)

The periodic Lorentz gas with external field and iso-kinetic thermostat is equivalent, by conformal transformation, to a billiard with expanding phase-space and slightly distorted scatterers, for which the trajectories are straight lines. A further time rescaling allows to keep the speed constant in that new geometry. In the hyperbolic regime, the stationary state of this billiard is characterized by a phase-space contraction rate, equal to that of the iso-kinetic Lorentz gas. In contrast to the iso-kinetic Lorentz gas where phase-space contraction occurs in the bulk, the phase-space contraction rate here takes place at the periodic boundaries.

Felipe Barra; Thomas Gilbert

2007-01-12T23:59:59.000Z

127

Space Systems  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Three months after installation, vibration was observed in a camera ... Space Station (ISS) experienced a failure with its starboard Solar Array ...

128

Rhombohedrally Distorted ?-Au5-xZn8+y Phases in the Au-Zn System  

SciTech Connect

The region of the Au–Zn phase diagram encompassing ?-brass-type phases has been studied experimentally from 45 to 85 atom % Zn. The ? phases were obtained directly from the pure elements by heating to 680 °C in evacuated silica tubes, followed by annealing at 300 °C. Powder X-ray and single-crystal diffraction studies show that ?-“Au5Zn8” phases adopt a rhombohedrally distorted Cr5Al8 structure type rather than the cubic Cu5Zn8 type. The refined compositions from two single crystals extracted from the Zn- and Au-rich loadings are Au4.27(3)Zn8.26(3)?0.47 (I) and Au4.58(3)Zn8.12(3)?0.3 (II), respectively (? = vacancy). These (I and II) refinements indicated both nonstatistical mixing of Au and Zn atoms as well as partially ordered vacancy distributions. The structures of these ? phases were solved in the acentric space group R3m (No. 160, Z = 6), and the observed lattice parameters from powder patterns were found to be a = 13.1029(6) and 13.1345(8) Å and c = 8.0410(4) and 8.1103(6) Å for crystals I and II, respectively. According to single-crystal refinements, the vacancies were found on the outer tetrahedron (OT) and octahedron (OH) of the 26-atom cluster. Single-crystal structural refinement clearly showed that the vacancy content per unit cell increases with increasing Zn, or valence-electron concentration. Electronic structure calculations, using the tight-binding linear muffin-tin orbital method with the atomic-sphere approximation (TB-LMTO-ASA) method, indicated the presence of a well-pronounced pseudogap at the Fermi level for “Au5Zn8” as the representative composition, an outcome that is consistent with the Hume–Rothery interpretation of ? brass.

Thimmaiah, Srinivasa [Ames Laboratory; Miller, Gordon J. [Ames Laboratory

2013-01-16T23:59:59.000Z

129

HUBBLE SPACE TELESCOPE SPECTRAL OBSERVATIONS NEAR THE He II Ly{alpha} BREAK: IMPLICATIONS FOR He II REIONIZATION  

SciTech Connect

Quasars that allow the study of intergalactic medium (IGM) He II are very rare, since they must be at high redshift along sightlines free of substantial hydrogen absorption, but recent work has dramatically expanded the number of such quasars known. We analyze two dozen higher-redshift (z = 3.1-3.9) low-resolution He II quasar spectra from the Hubble Space Telescope and find that their He II Gunn-Peterson troughs suggest exclusion of very early and very late reionization models, favoring a reionization redshift of z {approx} 3. Although the data quality is not sufficient to reveal details such as the expected redshift evolution of helium opacity, we obtain the first ensemble measure of helium opacity at high redshift averaged over many sightlines: {tau} = 4.90 at z {approx} 3.3. We also find that it would be very difficult to observe the IGM red wing of absorption from the beginning of He II reionization, but depending on the redshift of reionization and the size of ionization zones, it might be possible to do so in some objects with the current generation of UV spectrographs.

Syphers, David [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Anderson, Scott F.; Haggard, Daryl [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Zheng Wei [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Meiksin, Avery [Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Schneider, Donald P. [Department of Physics and Astronomy, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); York, Donald G., E-mail: David.Syphers@colorado.edu, E-mail: anderson@astro.washington.edu, E-mail: zheng@pha.jhu.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2011-01-10T23:59:59.000Z

130

Towards unifying multi-resolution and multi-description : a distortion-diversity perspective  

E-Print Network (OSTI)

We consider codec structures that exploit diversity in both source coding and channel coding components. We propose to study source-channel schemes using the tradeoff between end-to-end distortion level and the outage ...

Jing, Sheng, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

131

Topographic Distortion of a Cold Front over the Snake River Plain and Central Idaho Mountains  

Science Conference Proceedings (OSTI)

The topographic distortion of a cold front over the Snake River Plain (SRP) and central Idaho Mountains on 3 December 1998 is described using high-density surface observations from MesoWest, a collection of meteorological networks over the ...

W. James Steenburgh; Thomas R. Blazek

2001-06-01T23:59:59.000Z

132

Joint estimation and correction of geometric distortions for EPI functional MRI using harmonic retrieval  

E-Print Network (OSTI)

Magnetic resonance imaging (MRI) uses applied spatial variations in the magnetic field to encode spatial position. Therefore, nonuniformities in the main magnetic field can cause image distortions. In order to correct the ...

Nguyen, Hien M.

133

Space design  

Science Conference Proceedings (OSTI)

Space stations, Moon bases and Mars bases are artificial habitats intended to support human life in extreme conditions. Their purpose is to pursue human progress and to gain knowledge and experience of the environment surrounding our planet. This research ... Keywords: Human factors, Interior design, Space habitability, Sustainability, Vision

Irene Lia Schlacht; Henrik Birke

2011-06-01T23:59:59.000Z

134

Extremely Luminous Water Vapor Emission from a Type 2 Quasar at Redshift z = 0.66  

E-Print Network (OSTI)

A search for water masers in 47 Sloan Digital Sky Survey Type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L_sun, also the most powerful. The presence and detectability of water masers in quasars at z ~ 0.3-0.8 may provide a better understanding of quasar molecular tori and disks, as well as fundamental quasar and galaxy properties such as black hole masses. Water masers at cosmologically interesting distances may also eventually provide, via direct distance determinations, a new cosmological observable for testing the reality and properties of dark energy, currently inferred primarily through Type 1a supernova measurements.

Richard Barvainis; Robert Antonucci

2005-06-10T23:59:59.000Z

135

Measuring the redshift of standard sirens using the neutron star deformability  

E-Print Network (OSTI)

A recent study has shown that redshift information can be directly extracted from gravitational wave sources. This can be done by exploiting the tidal phasing contributions to the waveform during the inspiral phase of binary neutron stars coalescences. The original study investigated the viability of this idea in the context of the Einstein Telescope using a Fisher Matrix approach and in this paper, we further explore this idea using realistic simulations and Bayesian inference techniques. We find that the fractional accuracy with which the redshift can be measured is in the order of tens of percent, in agreement with Fisher Matrix predictions. Moreover, no significant bias is found. We conclude that, when tidal phasing contributions are included in the analysis, inference of the cosmological parameters from gravitational waves is possible

T. G. F. Li; W. Del Pozzo; C. Messenger

2013-03-04T23:59:59.000Z

136

Measuring the redshift of standard sirens using the neutron star deformability  

E-Print Network (OSTI)

A recent study has shown that redshift information can be directly extracted from gravitational wave sources. This can be done by exploiting the tidal phasing contributions to the waveform during the inspiral phase of binary neutron stars coalescences. The original study investigated the viability of this idea in the context of the Einstein Telescope using a Fisher Matrix approach and in this paper, we further explore this idea using realistic simulations and Bayesian inference techniques. We find that the fractional accuracy with which the redshift can be measured is in the order of tens of percent, in agreement with Fisher Matrix predictions. Moreover, no significant bias is found. We conclude that, when tidal phasing contributions are included in the analysis, inference of the cosmological parameters from gravitational waves is possible

Li, T G F; Messenger, C

2013-01-01T23:59:59.000Z

137

How to verify the redshift mechanism of low-energy quantum gravity  

E-Print Network (OSTI)

In the model of low-energy quantum gravity by the author, the redshift mechanism is quantum and local, and it is not connected with any expansion of the Universe. A few possibilities to verify its predictions are considered here: the specialized ground-based laser experiment; a deceleration of massive bodies and the Pioneer anomaly; a non-universal character of the Hubble diagram for soft and hard radiations; galaxy/quasar number counts.

Michael A. Ivanov

2008-09-10T23:59:59.000Z

138

The ESO Slice Project (ESP) galaxy redshift survey: II. The luminosity function and mean galaxy density  

E-Print Network (OSTI)

(Abridged) The ESO Slice Project (ESP) is a galaxy redshift survey we have completed as an ESO Key-Project over ~23 square degrees, in a region near the South Galactic Pole. The survey is nearly complete to the limiting magnitude b_J=19.4 and consists of 3342 galaxies with reliable redshift determination. The ESP survey is intermediate between shallow, wide angle samples and very deep, one-dimensional pencil beams: spanning a volume of ~ 5 x 10^4 Mpc^3 at the sensitivity peak (z ~ 0.1), it provides an accurate determination of the "local" luminosity function and the mean galaxy density. We find that, although a Schechter function is an acceptable representation of the luminosity function over the entire range of magnitudes (M -17. The amplitude and the alpha and M^* parameters of our luminosity function are in good agreement with those of the AUTOFIB redshift survey (Ellis et al. 1996). Viceversa, our amplitude is significantly higher, by a factor ~ 1.6 at M ~ M^*, than that found for both the Stromlo-APM (Loveday et al. 1992) and the Las Campanas (Lin et al. 1996) redshift surveys. Also the faint end slope of our luminosity function is significantly steeper than that found in these two surveys. Large over- and under- densities are clearly seen in our data. In particular, we find evidence for a "local" underdensity (for D < 140 Mpc) and a significant overdensity at z ~ 0.1. When these radial density variations are taken into account, our derived luminosity function reproduces very well the observed counts for b_J < 19.4, including the steeper than Euclidean slope for b_J < 17.

E. Zucca; G. Zamorani; G. Vettolani; A. Cappi; R. Merighi; M. Mignoli; G. M. Stirpe; H. MacGillivray; C. Collins; C. Balkowski; V. Cayatte; S. Maurogordato; D. Proust; G. Chincarini; L. Guzzo; D. Maccagni; R. Scaramella; A. Blanchard; M. Ramella

1997-05-13T23:59:59.000Z

139

THE EGNoG SURVEY: MOLECULAR GAS IN INTERMEDIATE-REDSHIFT STAR-FORMING GALAXIES  

SciTech Connect

We present the Evolution of molecular Gas in Normal Galaxies (EGNoG) survey, an observational study of molecular gas in 31 star-forming galaxies from z = 0.05 to z = 0.5, with stellar masses of (4-30) Multiplication-Sign 10{sup 10} M{sub Sun} and star formation rates of 4-100 M{sub Sun} yr{sup -1}. This survey probes a relatively un-observed redshift range in which the molecular gas content of galaxies is expected to have evolved significantly. To trace the molecular gas in the EGNoG galaxies, we observe the CO(J = 1 {yields} 0) and CO(J = 3 {yields} 2) rotational lines using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We detect 24 of 31 galaxies and present resolved maps of 10 galaxies in the lower redshift portion of the survey. We use a bimodal prescription for the CO to molecular gas conversion factor, based on specific star formation rate, and compare the EGNoG galaxies to a large sample of galaxies assembled from the literature. We find an average molecular gas depletion time of 0.76 {+-} 0.54 Gyr for normal galaxies and 0.06 {+-} 0.04 Gyr for starburst galaxies. We calculate an average molecular gas fraction of 7%-20% at the intermediate redshifts probed by the EGNoG survey. By expressing the molecular gas fraction in terms of the specific star formation rate and molecular gas depletion time (using typical values), we also calculate the expected evolution of the molecular gas fraction with redshift. The predicted behavior agrees well with the significant evolution observed from z {approx} 2.5 to today.

Bauermeister, A.; Blitz, L.; Wright, M. [Department of Astronomy and Radio Astronomy Laboratory, University of California at Berkeley, B-20 Hearst Field Annex, Berkeley, CA 94720 (United States); Bolatto, A.; Teuben, P. [Department of Astronomy and Laboratory for Millimeter-wave Astronomy, University of Maryland, College Park, MD 20742 (United States); Bureau, M. [Sub-department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Leroy, A. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Ostriker, E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Wong, T., E-mail: amberb@astro.berkeley.edu [Department of Astronomy, University of Illinois, MC-221, 1002 W. Green Street, Urbana, IL 61801 (United States)

2013-05-10T23:59:59.000Z

140

Dynamics of multi-body space interferometers including reaction wheel gyroscopic stiffening effects : structurally connected and electromagnetic formation of flying architectures  

E-Print Network (OSTI)

Space telescopes have the potential to revolutionize astronomy and our search for life-supporting planets beyond our Solar System. Free of atmospheric distortions, they are able to provide a much "clearer" view of the ...

Elias, Laila Mireille, 1977-

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

2XMM J083026+524133: The most X-ray luminous cluster at redshift 1  

E-Print Network (OSTI)

In the distant universe X-ray luminous clusters of galaxies are rare objects. Large area surveys are therefore needed to probe the high luminosity end of the cluster population at redshifts z >= 1. We correlated extended X-ray sources from the second XMM-Newton source catalogue (2XMM) with the SDSS in order to identify new clusters of galaxies. Distant cluster candidates in empty SDSS fields were imaged in the R and z bands with the Large Binocular Telescope. We extracted the X-ray spectra of the cluster candidates and fitted thermal plasma models to the data. We determined the redshift 0.99 +-0.03 for 2XMM J083026+524133 from its X-ray spectrum. With a bolometric luminosity of 1.8 x 10^45 erg/sec this is the most X-ray luminous cluster at redshifts z >= 1. We measured a gas temperature of 8.2 +- 0.9 keV and and estimate a cluster mass M(500) = 5.6 x 10^14 M(solar). The optical imaging revealed a rich cluster of galaxies.

G. Lamer; M. Hoeft; J. Kohnert; A. Schwope; J. Storm

2008-05-25T23:59:59.000Z

142

The ESO Slice Project (ESP) galaxy redshift survey: I. Description and First Results  

E-Print Network (OSTI)

The ESO Slice Project (ESP) is a galaxy redshift survey we have recently completed as an ESO Key-Project. The ESP covers 23.3 square degrees in a region close to the South Galactic Pole. The survey is nearly complete (85%) to the limiting magnitude b_J=19.4 and consists of 3342 galaxies with reliable redshift determination. In this paper, the first in a series that will present the results of the ESP survey, we describe the main characteristics of the survey and briefly discuss the properties of the galaxy sample. From a preliminary spectral analysis of a large sub-sample of 2550 galaxies we find that the fraction of actively star-forming galaxies increases from a few percent for the brightest galaxies up to about 40% for the galaxies fainter than M= -16.5. The most outstanding feature in the ESP redshift distribution is a very significant peak at z ~ 0.1. The detection of similar peaks, at the same distance, in other surveys in the same region of the sky, suggests the presence of a large bidimensional structure perpendicular to the line of sight. The minimum size of this structure would be of the order of 100 x 50 Mpc, comparable with the size of the Great Wall.

G. Vettolani; E. Zucca; G. Zamorani; A. Cappi; R. Merighi; M. Mignoli; G. M. Stirpe; H. MacGillivray; C. Collins; C. Balkowski; V. Cayatte; S. Maurogordato; D. Proust; G. Chincarini; L. Guzzo; D. Maccagni; R. Scaramella; A. Blanchard; M. Ramella

1997-04-11T23:59:59.000Z

143

Hydrodynamics of high-redshift galaxy collisions: From gas-rich disks to dispersion-dominated mergers and compact spheroids  

E-Print Network (OSTI)

Disk galaxies at high redshift (z~2) are characterized by high fractions of cold gas, strong turbulence, and giant star-forming clumps. Major mergers should typically involve such galaxies. High-redshift merger simulations, however, have always modeled the ISM as stable, homogeneous, and thermally pressurized. We present the first high-redshift merger simulations with cold, turbulent, and clumpy gas, and we discuss the major new features of these models compared to models where the gas is artificially stabilized and warmed. Gas turbulence, which is already strong in high-redshift disks, is further enhanced in mergers. Some phases are dispersion-dominated, with most of the gas kinetic energy in the form of velocity dispersion and very chaotic velocity fields, unlike low-redshift mergers. High-redshift mergers are also characterized by highly dissipative gas collapse to the center of mass, with the stellar component following in a global contraction. The final galaxies are early-type with relatively small radii...

Bournaud, Frederic; Delaye, Lauriane; Powell, Leila C; Elmegreen, Bruce G; Elmegreen, Debra Meloy; Duc, Pierre-Alain; Teyssier, Romain; Contini, Thierry; Epinat, Benoit; Shapiro, Kristen L

2010-01-01T23:59:59.000Z

144

Metric spaces with unique pretangent spaces  

E-Print Network (OSTI)

We find necessary and sufficient conditions under which an arbitrary metric space $X$ has a unique pretangent space at the marked point $a\\in X$. Key words: Metric spaces; Tangent spaces to metric spaces; Uniqueness of tangent metric spaces; Tangent space to the Cantor set.

Dovgoshey, Oleksiy; Kugukaslan, Mehmet

2009-01-01T23:59:59.000Z

145

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides  

NLE Websites -- All DOE Office Websites (Extended Search)

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals that leave noticeable voids in the crystal structure. At the ALS, researchers from the U.K., Ireland, and the U.S. have now obtained definitive experimental evidence that this lone-pair model must be revised. High-resolution x-ray photoemission spectroscopy (XPS) and soft x-ray emission spectroscopy (XES) have clarified the subtle electronic origins of the prototypical distortions in these crystal structures. The results have important implications for the tantalizing possibility of spintronic or superconducting devices combining ferroelectric and ferromagnetic properties.

146

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides  

NLE Websites -- All DOE Office Websites (Extended Search)

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals that leave noticeable voids in the crystal structure. At the ALS, researchers from the U.K., Ireland, and the U.S. have now obtained definitive experimental evidence that this lone-pair model must be revised. High-resolution x-ray photoemission spectroscopy (XPS) and soft x-ray emission spectroscopy (XES) have clarified the subtle electronic origins of the prototypical distortions in these crystal structures. The results have important implications for the tantalizing possibility of spintronic or superconducting devices combining ferroelectric and ferromagnetic properties.

147

A Simple, Low Cost Longitudinal Phase Space Diagnostic  

Science Conference Proceedings (OSTI)

For proper operation of the LCLS [1] x-ray free-electron laser (FEL), and other similar machines, measurement and control of the electron bunch longitudinal phase space is critical. The LCLS accelerator includes two bunch compressor chicanes to magnify the peak current. These magnetic chicanes can generate significant coherent synchrotron radiation (CSR), which can distort the phase space distribution. We propose a diagnostic scheme by exciting a weak skew quadrupole at an energy-chirped, high dispersion point in the first LCLS bunch compressor (BC1) to reconstruct longitudinal phase space on an OTR screen after BC1, allowing a time-resolved characterization of CSR effects.

Bertsche, Kirk; Emma, Paul; /SLAC; Shevchenko, Oleg; /Novosibirsk, IYF

2009-05-15T23:59:59.000Z

148

On the Metric of Space-time  

E-Print Network (OSTI)

Maxwell's equations are obeyed in a one-parameter group of isotropic gravity-free flat space-times whose metric depends upon the value of the group parameter. An experimental determination of this value has been proposed. If it is zero, the metric is Minkowski's. If it is non-zero, the metric is not Poincare invariant and local frequencies of electromagnetic waves change as they propagate. If the group parameter is positive, velocity independent red shifts develop and the group parameter plays a role similar to that of Hubble's constant in determining the relation of these redshifts to propagation distance. In the resulting space-times, the velocity dependence of Doppler shifts is a function of propagation distance. If the group parameter and Hubble's constant have the same order of magnitude, observed frequency shifts in radiation received from stellar sources can imply source velocities quite different from those implied in Minkowski space. In these space-times, electromagnetic waves received from bodies in galactic Kepler orbits undergo frequency shifts which are indistinguishable from shifts currently attributed to dark matter and dark energy in Minkowski space, or to a non-Newtonian physics.

Carl E. Wulfman

2013-02-02T23:59:59.000Z

149

On Optimum End-to-End Distortion in Wideband MIMO Systems  

E-Print Network (OSTI)

This paper presents the impact of frequency diversity on the optimum expected end-to-end distortion (EED) in an outage-free wideband multiple-input multiple-output (MIMO) system. We provide the closed-form expression of optimum asymptotic expected EED comprised of the optimum distortion exponent and the multiplicative optimum distortion factor for high signal-to-noise ratio (SNR). It is shown that frequency diversity can improve EED though it has no effect on ergodic capacity. The improvement becomes slight when the frequency diversity order is greater than a certain number. The lower bounds related to infinite frequency diversity are derived. The results for outage-free systems are the bounds for outage-suffering systems and they are instructive for system design.

Chen, Jinhui

2010-01-01T23:59:59.000Z

150

Approximate treatment of electron Coulomb distortion in quasielastic (e,e') reactions  

E-Print Network (OSTI)

In this paper we address the adequacy of various approximate methods of including Coulomb distortion effects in (e,e') reactions by comparing to an exact treatment using Dirac-Coulomb distorted waves. In particular, we examine approximate methods and analyses of (e,e') reactions developed by Traini et al. using a high energy approximation of the distorted waves and phase shifts due to Lenz and Rosenfelder. This approximation has been used in the separation of longitudinal and transverse structure functions in a number of (e,e') experiments including the newly published 208Pb(e,e') data from Saclay. We find that the assumptions used by Traini and others are not valid for typical (e,e') experiments on medium and heavy nuclei, and hence the extracted structure functions based on this formalism are not reliable. We describe an improved approximation which is also based on the high energy approximation of Lenz and Rosenfelder and the analyses of Knoll and compare our results to the Saclay data. At each step of our analyses we compare our approximate results to the exact distorted wave results and can therefore quantify the errors made by our approximations. We find that for light nuclei, we can get an excellent treatment of Coulomb distortion effects on (e,e') reactions just by using a good approximation to the distorted waves, but for medium and heavy nuclei simple additional ad hoc factors need to be included. We describe an explicit procedure for using our approximate analyses to extract so-called longitudinal and transverse structure functions from (e,e') reactions in the quasielastic region.

K. S. Kim; L. E. Wright; Yanhe Jin; D. W. Kosik

2005-03-30T23:59:59.000Z

151

The Environment on few Mpc scales of Infrared Luminous Galaxies at Redshifts z~1  

E-Print Network (OSTI)

We investigate the environment of infrared luminous galaxies (L$_{IR}$[8-1000 $\\mu $m$] >10^{11}$L$_{\\sun}$). We focus on the redshift range 0.7 $\\leq$ z $\\leq$ 1, where these galaxies dominate the star formation activity and play a significant role in galaxy evolution. We employ MIPS 24$\\mu$m data to identify infrared galaxies in the Extended Groth Strip (EGS). We use a local density indicator to probe the environment on few Mpc scales and a group member catalog, both of which make use of the DEEP2 spectroscopic redshift catalog, to quantify the environment of these galaxies. We find that the local environment of LIRGs and ULIRGs is intermediate between that of blue and red galaxies. LIRGs and ULIRGs avoid underdense environments and inhabit local environments that are more dense on average than those of other DEEP2 galaxies at similar redshifts. However, when the comparison sample of the non-IR DEEP2 galaxies is restricted to have the same range of stellar mass, color, or luminosity as the IR--galaxies, there is no longer any significant difference in environment; the IR-galaxies follow the same trends in the color-environment and luminosity-environment relations observed at z$\\sim$1. We also find that about 30% of the LIRGs and ULIRGs belong to groups, associated with a minimum dark matter halo of 6$\\times10^{12}$M$_{\\odot}$h$^{-1}$. The group members constitute 20 % of the sources responsible for the IR star formation rate density and comoving energy density at z$\\sim$1.

D. Marcillac; G. H. Rieke; C. Papovich; C. N. A. Willmer; B. J. Weiner; A. L. Coil; M. C. Cooper; B. F. Gerke; J. Woo; J. A. Newman; A. Georgakakis; E. S. Laird; K. Nandra; G. G. Fazio; J. -S. Huang; D. C. Koo

2007-12-01T23:59:59.000Z

152

The ESO Slice Project (ESP) galaxy redshift survey: VI Groups of Galaxies  

E-Print Network (OSTI)

In this paper we identify objectively and analyze groups of galaxies in the recently completed ESP survey. We find 231 groups above the number overdensity threshold delta(rho)/rho=80 in the redshift range 5000ESP galaxies within the same redshift range. The median velocity dispersion (corrected for measurement errors and computed at the redshift of the group) is sigma_{ESP,median} = 194 km/s. We show that our result is reliable in spite of the particular geometry of the ESP survey (two rows of tangent circular fields of radius 15 arcmin), which causes most systems to be only partially surveyed. In general, we find that the properties of ESP groups are consistent with those of groups in shallower (and wider) catalogs (e.g. CfA2N and SSRS2). As in shallower catalogs, ESP groups trace very well the geometry of the large scale structure. Our results are of particular interest because the depth of the ESP survey allows us to sample group properties over a large number of structures. We also compare luminosity function and spectral properties of galaxies that are members of groups with those of isolated galaxies. We find that galaxies in groups have a brighter M* with respect to non--member galaxies; the slope \\alpha is the same, within the errors, in the two cases. We find that 34% of ESP galaxies with detectable emission lines are members of groups. The fraction of galaxies without detectable emission lines in groups is significantly higher: 45%. More generally, we find a gradual decrease of the fraction of emission line galaxies among members of systems of increasing richness. This result confirms that the morphology-density relation found for clusters also extends toward systems of lower density.

M. Ramella; G. Zamorani; E. Zucca; G. M. Stirpe; G. Vettolani; C. Balkowski; A. Blanchard; A. Cappi; V. Cayatte; G. Chincarini; C. Collins; L. Guzzo; H. MacGillivray; D. Maccagni; S. Maurogordato; R. Merighi; M. Mignoli; A. Pisani; D. Proust; R. Scaramella

1998-11-10T23:59:59.000Z

153

High-redshift blazar identification for Swift J1656.3-3302  

E-Print Network (OSTI)

We report on the high-redshift blazar identification of a new gamma-ray source, Swift J1656.3-3302, detected with the BAT imager onboard the Swift satellite and the IBIS instrument on the INTEGRAL satellite. Follow-up optical spectroscopy has allowed us to identify the counterpart as an R-band 19 mag source that shows broad Lyman-alpha, Si IV, He II, C IV, and C III] emission lines at redshift z = 2.40+-0.01. Spectral evolution is observed in X-rays when the INTEGRAL/IBIS data are compared to the Swift/BAT results, with the spectrum steepening when the source gets fainter. The 0.7-200 keV X-ray continuum, observed with Swift/XRT and INTEGRAL/IBIS, shows the power law shape typical of radio loud (broad emission line) active galactic nuclei (with a photon index around 1.6) and a hint of spectral curvature below 2 keV, possibly due to intrinsic absorption (N_H about 7e22 cm-2) local to the source. Alternatively, a slope change (of about 1 in terms of photon index) around 2.7 keV can describe the X-ray spectrum equally well. At this redshift, the observed 20-100 keV luminosity of the source is about 1e48 erg s-1 (assuming isotropic emission), making Swift J1656.3-3302 one of the most X-ray luminous blazars. This source is yet another example of a distant gamma-ray loud quasar discovered above 20 keV. It is also the farthest object, among the previously unidentified INTEGRAL sources, whose nature has been determined a posteriori through optical spectroscopy.

N. Masetti; E. Mason; R. Landi; P. Giommi; L. Bassani; A. Malizia; A. J. Bird; A. Bazzano; A. J. Dean; N. Gehrels; E. Palazzi; P. Ubertini

2008-01-18T23:59:59.000Z

154

A high dimensional delay selection for the reconstruction of proper phase space with cross auto-correlation  

Science Conference Proceedings (OSTI)

For the purpose of phase space reconstruction from nonlinear time series, delay selection is one of the most vital criteria. This is normally done by using a general measure viz., mutual information (MI). However, in that case, the delay selection is ... Keywords: Cross auto-correlation, Dynamical system, Phase space reconstructions, Shape distortion measure

Sanjay Kumar Palit, Sayan Mukherjee, D. K. Bhattacharya

2013-08-01T23:59:59.000Z

155

Vacuum oscillations of solar neutrinos: correlation between spectrum distortion and seasonal variations  

E-Print Network (OSTI)

Long length vacuum oscillations solution of the solar neutrino problem is discussed. We show that there is a strict correlation between a distortion of the neutrino energy spectrum and an amplitude of seasonal variations of the neutrino flux. The slope parameter which characterizes a distortion of the recoil electron energy spectrum in the Super-Kamiokande experiment and the seasonal asymmetry of the signal have been calculated in a wide range of oscillation parameters. The correlation of the slope and asymmetry gives crucial criteria for identification or exclusion of this solution. For the positive slope indicated by preliminary Super-Kamiokande data we predict (40 - 60) % enhancement of the seasonal variations.

S. P. Mikheyev; A. Yu. Smirnov

1997-08-19T23:59:59.000Z

156

The nature of the extreme kinematics in the extended gas of high redshift radio galaxies  

E-Print Network (OSTI)

We present UV rest frame spectra of 3 powerful narrow line radio galaxies and the hyperluminous type 2 active galaxy SMM02399-0136, all at high redshift (z>2). We find high velocities (FWHM>1000, km/s) in the extended gas of all objects. A natural explanation is the interaction between the radio jet and the ambient gas, that drives shocks into the gas and accelerates the clouds. However, the existence of high velocities in regions where such interactions are not taking place implies that other processes can play a role. We discuss here several possible mechanisms.

M. Villar-Martin; L. Binette; R. A. E. Fosbury

1999-03-09T23:59:59.000Z

157

AN OBSERVED LINK BETWEEN ACTIVE GALACTIC NUCLEI AND VIOLENT DISK INSTABILITIES IN HIGH-REDSHIFT GALAXIES  

Science Conference Proceedings (OSTI)

We provide evidence for a correlation between the presence of giant clumps and the occurrence of active galactic nuclei (AGNs) in disk galaxies. Giant clumps of 10{sup 8}-10{sup 9} M{sub Sun} arise from violent gravitational instability in gas-rich galaxies, and it has been proposed that this instability could feed supermassive black holes (BHs). We use emission line diagnostics to compare a sample of 14 clumpy (unstable) disks and a sample of 13 smoother (stable) disks at redshift z {approx} 0.7. The majority of clumpy disks in our sample have a high probability of containing AGNs. Their [O III] {lambda}5007 emission line is strongly excited, inconsistent with low-metallicity star formation (SF) alone. [Ne III] {lambda}3869 excitation is also higher. Stable disks rarely have such properties. Stacking ultra sensitive Chandra observations (4 Ms) reveals an X-ray excess in clumpy galaxies, which confirms the presence of AGNs. The clumpy galaxies in our intermediate-redshift sample have properties typical of gas-rich disk galaxies rather than mergers, being in particular on the main sequence of SF. This suggests that our findings apply to the physically similar and numerous gas-rich unstable disks at z > 1. Using the observed [O III] and X-ray luminosities, we conservatively estimate that AGNs hosted by clumpy disks have typical bolometric luminosities of the order of a few 10{sup 43} erg s{sup -1}, BH growth rates m-dot{sub BH}{approx}10{sup -2} M{sub Sun} yr{sup -1}, and that these AGNs are substantially obscured in X-rays. This moderate-luminosity mode could provide a large fraction of today's BH mass with a high duty cycle (>10%), accretion bursts with higher luminosities being possible over shorter phases. Violent instabilities at high redshift (giant clumps) are a much more efficient driver of BH growth than the weak instabilities in nearby spirals (bars), and the evolution of disk instabilities with mass and redshift could explain the simultaneous downsizing of SF and of BH growth.

Bournaud, Frederic; Juneau, Stephanie; Le Floc'h, Emeric; Mullaney, James; Daddi, Emanuele; Duc, Pierre-Alain; Elbaz, David; Salmi, Fadia [CEA, IRFU, SAp, F-91191 Gif-sur-Yvette (France); Dekel, Avishai [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Dickinson, Mark [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

2012-09-20T23:59:59.000Z

158

Quantitative comparison between Type Ia supernova spectra at low and high redshifts: A case study  

E-Print Network (OSTI)

Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space

Garavini, G.; Supernova Cosmology Project

2008-01-01T23:59:59.000Z

159

The discovery of high-redshift supernovae and their cosmological implications  

SciTech Connect

In this thesis the author discusses the methodology for doing photometry: from procedure of extracting supernova counts from images that contain combined supernova plus galaxy flux, to standard star calibration, to additional instrumental corrections that arise due to the multiple telescopes used for observations. He discusses the different sources of photometric error and their correlations, and the construction of the covariance matrix for all the points in the light curve. He then describes the K corrections which account for the redshifting of spectra that are necessary to compare the photometry of the high-redshift data with those from nearby (z < 0.1) supernovae. Finally, he uses the first seven of the supernovae to test the hypothesis that they live in an under-dense bubble where the locally measured Hubble constant differs significantly from the true Hubble constant. He also uses the data to place limits on the value of the Hubble constant. Discussions of several other important aspects of the data analysis are or will be included in other papers. These topics include a description of how the covariance matrix is used to generate light-curve fits, a discussion of non-photometric systematic errors that also effect the measurements, and a discussion of the application of the supernovae to address other scientific/cosmological problems.

Kim, A.G. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Physics Div.

1997-09-01T23:59:59.000Z

160

Clusters, Groups, and Filaments in the Chandra Deep Field-South up to Redshift 1  

E-Print Network (OSTI)

We present a comprehensive structure detection analysis of the 0.3 square degree area of the MUSYC-ACES field which covers the Chandra Deep Field-South (CDFS). Using a density-based clustering algorithm on the MUSYC and ACES photometric and spectroscopic catalogues we find 62 over-dense regions up to redshifts of 1, including, clusters, groups and filaments. All structures are confirmed using the DBSCAN method, including the detection of nine structures previously reported in the literature. We present a catalogue of all structures present including their central position, mean redshift, velocity dispersions, and classification based on their morphological and spectroscopic distributions. In particular we find 13 galaxy clusters and 6 large groups/small clusters. Comparison of these massive structures with published XMM-Newton imaging (where available) shows that $80\\%$ of these structures are associated with diffuse, soft-band (0.4 - 1 keV) X-ray emission including $90\\%$ of all objects classified as cluster...

Dehghan, Siamak

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Molecules at high Redshift: The Evolution of the Cool Phase of Protogalactic Disks  

E-Print Network (OSTI)

We study the formation of molecular hydrogen, after the epoch of re-ionization, in the context of canonical galaxy formation theory due to hierarchical clustering. There is an initial epoch of $H_2$ production in the gas phase through the $H^-$ route which ends at a redshift of order unity. Star formation in the protogalactic disks can become self-regulated. The process responsible for the feedback is heating of the gas by the internal stellar radiation field which can dominate the background radiation field at various epochs. It is possible to define a maximum star formation rate during this epoch. Plausible estimates give a rate of 0.2-2 Mo yr-1 for condensations corresponding to 1 sigma and 2 sigma initial density fluctuations. Therefore, the production of metals and dust proceeds slowly in this phase. This moderate epoch is terminated by a phase transition to a cold dense and warm neutral/ionized medium once the metals and dust have increased to a level Z=0.03-0.1 Z_o. Then: (1) atoms and molecules such as C, O and CO become abundant and cool the gas to below $300 K$ ; (2) the dust abundance has become sufficiently high to allow shielding of the molecular gas and; (3) molecular hydrogen formation can occur rapidly on grain surfaces. This phase transition occurs at a redshift of approximately 1.5, with a fiducial range of 1.2natural resolution of the G-dwarf problem.

Colin A. Norman; Marco Spaans

1996-11-21T23:59:59.000Z

162

High-redshift blazar identification for Swift J1656.3-3302  

E-Print Network (OSTI)

We report on the high-redshift blazar identification of a new gamma-ray source, Swift J1656.3-3302, detected with the BAT imager onboard the Swift satellite and the IBIS instrument on the INTEGRAL satellite. Follow-up optical spectroscopy has allowed us to identify the counterpart as an R-band 19 mag source that shows broad Lyman-alpha, Si IV, He II, C IV, and C III] emission lines at redshift z = 2.40+-0.01. Spectral evolution is observed in X-rays when the INTEGRAL/IBIS data are compared to the Swift/BAT results, with the spectrum steepening when the source gets fainter. The 0.7-200 keV X-ray continuum, observed with Swift/XRT and INTEGRAL/IBIS, shows the power law shape typical of radio loud (broad emission line) active galactic nuclei (with a photon index around 1.6) and a hint of spectral curvature below 2 keV, possibly due to intrinsic absorption (N_H about 7e22 cm-2) local to the source. Alternatively, a slope change (of about 1 in terms of photon index) around 2.7 keV can describe the X-ray spectrum e...

Masetti, N; Landi, R; Giommi, P; Bassani, L; Malizia, A; Bird, A J; Bazzano, A; Dean, A J; Gehrels, N; Palazzi, E; Ubertini, P

2008-01-01T23:59:59.000Z

163

A Rate-Energy-Distortion Analysis for Compressed-Sensing-Enabled Wireless Video Streaming on  

E-Print Network (OSTI)

A Rate-Energy-Distortion Analysis for Compressed-Sensing-Enabled Wireless Video Streaming. The objective of this paper is to conduct an experiment- driven analysis of the energy on Multimedia Sensors Scott Pudlewski, Tommaso Melodia Department of Electrical Engineering State University

Melodia, Tommaso

164

Region-of-interest video coding based on rate and distortion variations for H.263+  

Science Conference Proceedings (OSTI)

Region-of-interest (ROI) is an essential task that one must undertake in low bit-rate multimedia communications because of the limited bandwidth of the channels and the transcoder between different standards. In this paper, an effective ROI determination ... Keywords: H.263+, Rate control, Rate-distortion, Region-of-interest, Videoconference

Ming-Chieh Chi; Mei-Juan Chen; Chia-Hung Yeh; Jyong-An Jhu

2008-02-01T23:59:59.000Z

165

Interference Suppression Consisting of Pre-distortion Filtering and Selective Transmit Diversity  

Science Conference Proceedings (OSTI)

In this paper we present and evaluate a pre-distortion (PD) scheme for the downlink of Wideband-code division multiple access (W-CDMA) systems considering a Rake in the receiver in order to exploit multipath diversity. Its performance is compared with ... Keywords: Downlink transmission, Frequency-selective channels, Pre-processing, Selective transmit diversity, W-CDMA

Mário Marques Silva; Américo M. Correia; Rui Dinis

2008-10-01T23:59:59.000Z

166

Using quad smoothness to efficiently control capacity-distortion of reversible data hiding  

Science Conference Proceedings (OSTI)

One of the main uses of data hiding is to protect secret messages being transmitted on the Internet. Reversible data hiding can fully recover the original host image after extracting the secret message. It is especially suitable for applications where, ... Keywords: Capacity-distortion control, Difference expansion, Reversible data hiding, Steganography

Chi-Nan Lin; Daniel J. Buehrer; Chin-Chen Chang; Tzu-Chuen Lu

2010-10-01T23:59:59.000Z

167

The Evolution of Distorted Rotating Black Holes I: Methods and Tests  

E-Print Network (OSTI)

We have developed a new numerical code to study the evolution of distorted, rotating black holes. We discuss the numerical methods and gauge conditions we developed to evolve such spacetimes. The code has been put through a series of tests, and we report on (a) results of comparisons with codes designed to evolve non-rotating holes, (b) evolution of Kerr spacetimes for which analytic properties are known, and (c) the evolution of distorted rotating holes. The code accurately reproduces results of the previous NCSA non-rotating code and passes convergence tests. New features of the evolution of rotating black holes not seen in non-rotating holes are identified. With this code we can evolve rotating black holes up to about $t=100M$, depending on the resolution and angular momentum. We also describe a new family of black hole initial data sets which represent rotating holes with a wide range of distortion parameters, and distorted non-rotating black holes with odd-parity radiation. Finally, we study the limiting slices for a maximally sliced rotating black hole and find good agreement with theoretical predictions.

Steven R. Brandt; Edward Seidel

1994-12-22T23:59:59.000Z

168

Impact of lattice geometry distortion due to ageing on selected physics parameters of a CANDU reactor  

SciTech Connect

In this paper, results related to a limited scope assessment of the geometry-distortion-induced effects on key reactor physics parameters of a CANDU reactor are discussed. These results were generated by simulations using refined analytical methods and detailed modeling of CANDU reactor core with aged lattice cell geometry. (authors)

Tholammakkil, J. [Canadian Nuclear Safety Commission, P.O. Box 1046, Ottawa, Ont. (Canada); Rahnema, F. [Georgia Inst. of Technology, Atlanta, GA 30332-0405 (United States); Ilas, G. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Stamm'ler, R. [Studsvik Scandpower AS, P.O. Box 15, NO-2027 Kjeller (Norway); Khotylev, V.; Serghiuta, D. [Canadian Nuclear Safety Commission, P.O. Box 1046, Ottawa, Ont. (Canada)

2006-07-01T23:59:59.000Z

169

Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings  

SciTech Connect

Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting���¢��������s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125�������°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU���¢��������s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

Christoph Beckermann; Kent Carlson

2011-07-22T23:59:59.000Z

170

Cosmic GRB energy-redshift relation and Primordial flares as possible energy source for the central engine  

E-Print Network (OSTI)

By considering similar observed properties of gamma ray bursts (GRB) and solar flares with the prevailing physical conditions in the cosmic environment, the following study suggests that most likely and promising energy source for the central engine which triggers GRB may be due to primordial flares, solar flare like phenomena, at the sites of inter galactic or inter galactic clusters in the early universe. The derived energy-redshift relation, E = E_{0}{(1+z)}^3 (where E is the amount of energy released, z is the redshift of GRB and E_{0} is a constant which is estimated to be ~ 10^{52} ergs), from the simple flare mechanism, is confirmed from the least square fit with the observed energy-redshift relation. Some of the physical parameters like length scale, strength of magnetic field, etc., of the flaring region of the GRB are estimated.

Hiremath, K M

2009-01-01T23:59:59.000Z

171

Analytical modeling of pulse-pileup distortion using the true pulse shape; applications to Fermi-GBM  

E-Print Network (OSTI)

Pulse-pileup affects most photon counting systems and occurs when photon detections occur faster than the detector's registration and recovery time. At high input rates, shaped pulses interfere and the source spectrum, as well as intensity information, get distorted. For instruments using bipolar pulse shaping there are two aspects to consider: `peak' and `tail' pileup effects, which raise and lower the measured energy, respectively. Peak effects have been extensively modeled in the past. Tail effects have garnered less attention due to the increased complexity: bipolar tails mean the tail pulse-height measurement depends on events in more than one time interval. We leverage previous work to derive an accurate, semi-analytical prediction for peak and tail pileup, up to high orders. We use the true pulse shape from the detectors of the Fermi Gamma-ray Burst Monitor. The measured spectrum is calculated by writing exposure time as a state-space expansion of overlapping pileup states and is valid up to very high rates. This expansion models losses due to fixed and extendable deadtime by averaging overlap configurations. Additionally, the model correctly predicts energy-dependent losses due to tail subtraction (sub-threshold) effects. We discuss pileup losses in terms of the true rate of photon detections versus the recorded count rate.

Vandiver Chaplin; Narayana Bhat; Michael Briggs; Valerie Connaughton

2012-11-28T23:59:59.000Z

172

THE AGE-REDSHIFT RELATION FOR LUMINOUS RED GALAXIES OBTAINED FROM FULL SPECTRUM FITTING AND ITS COSMOLOGICAL IMPLICATIONS  

SciTech Connect

The relative age of galaxies at different redshifts can be used to infer the Hubble parameter and put constraints on cosmological models. We select luminous red galaxies (LRGs) from the Sloan Digital Sky Survey Data Release 7 and then cross match it with the MPA/JHU catalog of galaxies to obtain a large sample of quiescent LRGs at redshift z {approx} 0.03-0.39. The total number of quiescent LRGs, 23,883, is divided into four sub-samples according to their velocity dispersions and each sub-sample is further divided into 12 redshift bins. The spectra of the LRGs in each redshift and velocity bin are co-added in order to obtain a combined spectrum with a relatively high signal-to-noise ratio. Adopting the GalexEV/SteLib model, we estimate the mean ages of the LRGs from these combined spectra by using the full-spectrum fitting method. We check the reliability of the estimated age by using Monte Carlo simulations and find that the estimates are robust and reliable. Assuming that the LRGs in each sub-sample and each redshift bin were on average formed at the same time, the Hubble parameter at the present time H {sub 0} is estimated from the age-redshift relation obtained for each sub-sample, which is compatible with the H {sub 0} value measured by other methods. We demonstrate that a systematic bias (up to {approx}20%) may be introduced to the H {sub 0} estimation because of recent star formation in the LRGs due to the later major mergers at z {approx}< 0.4, but this bias may be negligible for those sub-samples with large velocity dispersions. Using the age-redshift relations obtained from the sub-sample with the largest velocity dispersion or the two sub-samples with high velocity dispersions, we find H {sub 0} = 65{sup +7} {sub -3} km s{sup -1} Mpc{sup -1} or H {sub 0} = 74{sup +5} {sub -4} km s{sup -1} Mpc{sup -1} by assuming a spatially flat {Lambda}CDM cosmology. With upcoming surveys, such as the Baryon Oscillation Spectroscopic Survey, even larger samples of quiescent massive LRGs may be obtained, and thus the Hubble parameter can be measured with high accuracy usimg the age-redshift relation.

Liu Gaochao; Lu Youjun; Chen Xuelei; Zhao Yongheng; Du Wei; Meng Xianmin [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China)

2012-10-20T23:59:59.000Z

173

METALLICITY-DEPENDENT QUENCHING OF STAR FORMATION AT HIGH REDSHIFT IN SMALL GALAXIES  

SciTech Connect

The star formation rates (SFRs) of low-metallicity galaxies depend sensitively on the gas metallicity, because metals are crucial to mediating the transition from intermediate-temperature atomic gas to cold molecular gas, a necessary precursor to star formation. We study the impact of this effect on the star formation history of galaxies. We incorporate metallicity-dependent star formation and metal enrichment in a simple model that follows the evolution of a halo main progenitor. Our model shows that including the effect of metallicity leads to suppression of star formation at redshift z > 2 in dark halos with masses {approx}< 10{sup 11} M{sub Sun }, with the suppression becoming near total for halos below {approx}10{sup 9.5}-10{sup 10} M{sub Sun }. We find that at high redshift, until z {approx} 2, the SFR cannot catch up with the gas inflow rate (IR), because the SFR is limited by the free-fall time, and because it is suppressed further by a lack of metals in small halos. As a result, in each galaxy the SFR is growing in time faster than the IR, and the integrated cosmic SFR density is rising with time. The suppressed in situ SFR at high-z makes the growth of stellar mass dominated by ex situ SFR, meaning stars formed in lower mass progenitor galaxies and then accreted, which implies that the specific SFR (sSFR) remains constant with time. The intensely accreted gas at high-z is accumulating as an atomic gas reservoir. This provides additional fuel for star formation in 10{sup 10}-10{sup 12} M{sub Sun} halos at z {approx} 1-3, which allows the SFR to exceed the instantaneous IR, and may enable an even higher outflow rate. At z < 1, following the natural decline in IR with time due to the universal expansion, the SFR and sSFR are expected to drop. We specify the expected dependence of sSFR and metallicity on stellar mass and redshift. At a given z, and below a critical mass, these relations are predicted to be flat and rising, respectively. Our model predictions qualitatively match some of the puzzling features in the observed star formation history.

Krumholz, Mark R. [Astronomy Department, University of California, Santa Cruz, CA 95060 (United States); Dekel, Avishai, E-mail: krumholz@ucolick.edu, E-mail: dekel@phys.huji.ac.il [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

2012-07-01T23:59:59.000Z

174

The Deepest Spectrum of the Universe? Constraints on the Lyman Continuum Background at High Redshift  

E-Print Network (OSTI)

We describe an ongoing experiment to search for the meta-galactic Lyman-continuum background at z~2-3. We are obtaining one of the deepest optical spectra ever, using LRIS/Keck-II to search for the fluorescent Ly-alpha emission from optically thick HI clouds. The null results of our pilot study (Bunker, Marleau & Graham 1998) placed a 3-sigma upper bound on the mean intensity of the ionizing background of J_{nu 0} radiation field. We have recently greatly extended our search, obtaining a 16-hour spectrum which is sensitive to UV background fluxes ~1E-21 erg/s/cm^2/Hz/sr (z~2.3 at 3-sigma, assuming the HI clouds are ~10arcsec in extent). We describe how the results of this study can be used to constrain the quasar luminosity function and the contribution of high-redshift star-forming galaxies to the ambient ionizing background.

Andrew J. Bunker; Francine R. Marleau; James R. Graham

1999-12-31T23:59:59.000Z

175

Distortions of Experimental Muon Arrival Time Distributions of Extensive Air Showers by the Observation Conditions  

E-Print Network (OSTI)

Event-by-event measured arrival time distributions of Extensive Air Shower (EAS) muons are affected and distorted by various interrelated effects which originate from the time resolution of the timing detectors, from fluctuations of the reference time and the number (multiplicity) of detected muons spanning the arrival time distribution of the individual EAS events. The origin of these effects is discussed, and different correction procedures, which involve detailed simulations, are proposed and illustrated. The discussed distortions are relevant for relatively small observation distances (R < 200 m) from the EAS core. Their significance decreases with increasing observation distance and increasing primary energies. Local arrival time distributions which refer to the observed arrival time of the first local muon prove to be less sensitive to the mass of the primary. This feature points to the necessity of arrival time measurements with additional information on the curvature of the EAS disk.

R. Haeusler; A. F. Badea; H. Rebel; I. M. Brancus; J. Oehlschlaeger

2001-10-17T23:59:59.000Z

176

Coulomb Distortion Effects for (e,e'p) Reactions at High Electron Energy  

E-Print Network (OSTI)

We report a significant improvement of an approximate method of including electron Coulomb distortion in electron induced reactions at momentum transfers greater than the inverse of the size of the target nucleus. In particular, we have found a new parametrization for the elastic electron scattering phase shifts that works well at all electron energies greater than 300 $MeV$. As an illustration, we apply the improved approximation to the $(e,e'p)$ reaction from medium and heavy nuclei. We use a relativistic ``single particle'' model for $(e,e'p)$ as as applied to $^{208}Pb(e,e'p)$ and to recently measured data at CEBAF on $^{16}O(e,e'p)$ to investigate Coulomb distortion effects while examining the physics of the reaction.

K. S. Kim; L. E. Wright

1999-07-09T23:59:59.000Z

177

Bulk flows from galaxy luminosities: application to 2MASS redshift survey and forecast for next-generation datasets  

E-Print Network (OSTI)

We present a simple method for measuring cosmological bulk flows from large redshift surveys, based on the apparent dimming or brightening of galaxies due to their peculiar motion. It is aimed at estimating bulk flows of cosmological volumes containing large numbers of galaxies. Constraints on the bulk flow are obtained by minimizing systematic variations in galaxy luminosities with respect to a reference luminosity function measured from the whole survey. This method offers two advantages over more popular bulk flow estimators: it is independent of error-prone distance indicators and of the poorly-known galaxy bias. We apply the method to the 2MASS redshift survey (2MRS) to measure the local bulk flows of spherical shells centered on the Milky Way (MW). The result is consistent with that obtained by Nusser and Davis (2011) using the SFI++ catalogue of Tully-Fisher distance indicators. We also make an assessment of the ability of the method to constrain bulk flows at larger redshifts ($z=0.1-0.5$) from next generation datasets. As a case study we consider the planned EUCLID survey. Using this method we will be able to measure a bulk motion of $ \\sim 200 \\kms$ of $10^6$ galaxies with photometric redshifts, at the $3\\sigma$ level for both $z\\sim 0.15$ and $z\\sim 0.5$. Thus the method will allow us to put strong constraints on dark energy models as well as alternative theories for structure formation.

Adi Nusser; Enzo Branchini; Marc Davis

2011-02-21T23:59:59.000Z

178

Coulomb Distortion Effects for Electron or Positron Induced $(e,e')$ Reactions in the Quasielastic Region  

E-Print Network (OSTI)

In response to recent experimental studies we investigate Coulomb distortion effects on $(e,e')$ reactions from medium and heavy nuclei for the case of electrons and positrons. We extend our previously reported full DWBA treatment of Coulomb distortions to the case of positrons for the $^{208}Pb(e,e')$ reaction in the quasielastic region for a particular nuclear model. In addition, we use previously reported successful approaches to treating Coulomb corrections in an approximate way to calculate the Coulomb distortion effects for $(e,e')$ reactions for both electrons and positrons for the case of a simple nuclear model for quasielastic knock-out of nucleons. With these results in hand we develop a simple {\\em ad-hoc} approximation for use in analyzing experiments, and discuss methods of extracting the ``longitudinal structure function" which enters into evaluation of the Coulomb sum rule. These techniques are generally valid for lepton induced reactions on nuclei with momentum transfers greater than approximately 300 $MeV/c$.

K. S. Kim; L. E. Wright; D. A. Resler

2001-03-13T23:59:59.000Z

179

RAPID, MACHINE-LEARNED RESOURCE ALLOCATION: APPLICATION TO HIGH-REDSHIFT GAMMA-RAY BURST FOLLOW-UP  

Science Conference Proceedings (OSTI)

As the number of observed gamma-ray bursts (GRBs) continues to grow, follow-up resources need to be used more efficiently in order to maximize science output from limited telescope time. As such, it is becoming increasingly important to rapidly identify bursts of interest as soon as possible after the event, before the afterglows fade beyond detectability. Studying the most distant (highest redshift) events, for instance, remains a primary goal for many in the field. Here, we present our Random Forest Automated Triage Estimator for GRB redshifts (RATE GRB-z ) for rapid identification of high-redshift candidates using early-time metrics from the three telescopes onboard Swift. While the basic RATE methodology is generalizable to a number of resource allocation problems, here we demonstrate its utility for telescope-constrained follow-up efforts with the primary goal to identify and study high-z GRBs. For each new GRB, RATE GRB-z provides a recommendation-based on the available telescope time-of whether the event warrants additional follow-up resources. We train RATE GRB-z using a set consisting of 135 Swift bursts with known redshifts, only 18 of which are z > 4. Cross-validated performance metrics on these training data suggest that {approx}56% of high-z bursts can be captured from following up the top 20% of the ranked candidates, and {approx}84% of high-z bursts are identified after following up the top {approx}40% of candidates. We further use the method to rank 200 + Swift bursts with unknown redshifts according to their likelihood of being high-z.

Morgan, A. N.; Richards, Joseph W.; Butler, Nathaniel R.; Bloom, Joshua S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Long, James; Broderick, Tamara, E-mail: amorgan@astro.berkeley.edu [Department of Statistics, University of California, Berkeley, CA 94720-3860 (United States)

2012-02-20T23:59:59.000Z

180

Design and analysis of a scanning beam interference lithography system for patterning gratings with nanometer-level distortions  

E-Print Network (OSTI)

This thesis describes the design and analysis of a system for patterning large-area gratings with nanometer level phase distortions. The novel patterning method, termed scanning beam interference lithography (SBIL), uses ...

Konkola, Paul Thomas, 1973-

2003-01-01T23:59:59.000Z

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181

DUST EXTINCTION BIAS IN THE COLUMN DENSITY DISTRIBUTION OF GAMMA-RAY BURSTS: HIGH COLUMN DENSITY, LOW-REDSHIFT GRBs ARE MORE HEAVILY OBSCURED  

SciTech Connect

The afterglows of gamma-ray bursts (GRBs) have more soft-X-ray absorption than expected from the foreground gas column in the Galaxy. While the redshift of the absorption can in general not be constrained from current X-ray observations, it has been assumed that the absorption is due to metals in the host galaxy of the GRB. The large sample of X-ray afterglows and redshifts now available allows the construction of statistically meaningful distributions of the metal column densities. We construct such a sample and show, as found in previous studies, that the typical absorbing column density (N{sub H{sub X}}) increases substantially with redshift, with few high column density objects found at low-to-moderate redshifts. We show, however, that when highly extinguished bursts are included in the sample, using redshifts from their host galaxies, high column density sources are also found at low-to-moderate redshift. We infer from individual objects in the sample and from observations of blazars that the increase in column density with redshift is unlikely to be related to metals in the intergalactic medium or intervening absorbers. Instead we show that the origin of the apparent increase with redshift is primarily due to dust extinction bias: GRBs with high X-ray absorption column densities found at z {approx}< 4 typically have very high dust extinction column densities, while those found at the highest redshifts do not. It is unclear how such a strongly evolving N{sub H{sub X}}/A{sub V} ratio would arise, and based on current data, remains a puzzle.

Watson, Darach [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Jakobsson, Pall, E-mail: darach@dark-cosmology.dk, E-mail: pja@raunvis.hi.is [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhaga 5, IS-107 Reykjavik (Iceland)

2012-08-01T23:59:59.000Z

182

Network-Adaptive Video Communication Using Packet Path Diversity and Rate-Distortion Optimized Reference Picture Selection  

Science Conference Proceedings (OSTI)

In this paper, we present error-resilient Internet video transmission using path diversity and rate-distortion optimized reference picture selection. Under this scheme, the optimal packet dependency is determined adapting to network characteristics and ... Keywords: Path diversity, error-resilient video coding, low-latency, network-adaptive video coding, rate-distortion optimization, reference picture selection, source-channel coding, video streaming

Yi J. Liang; Eric Setton; Bernd Girod

2005-11-01T23:59:59.000Z

183

Virtually distortion-free imaging system for large field, high resolution lithography using electrons, ions or other particle beams  

DOE Patents (OSTI)

Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position. Particle beams, including electrons, ions and neutral particles, may be used as well as electromagnetic radiation.

Hawryluk, A.M.; Ceglio, N.M.

1991-04-10T23:59:59.000Z

184

Virtually distortion-free imaging system for large field, high resolution lithography using electrons, ions or other particle beams  

DOE Patents (OSTI)

Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position. Particle beams, including electrons, ions and neutral particles, may be used as well as electromagnetic radiation.

Hawryluk, Andrew M. (Modesto, CA); Ceglio, Natale M. (Livermore, CA)

1993-01-01T23:59:59.000Z

185

Image-based spectral distortion correction for photon-counting x-ray detectors  

Science Conference Proceedings (OSTI)

Purpose: To investigate the feasibility of using an image-based method to correct for distortions induced by various artifacts in the x-ray spectrum recorded with photon-counting detectors for their application in breast computed tomography (CT). Methods: The polyenergetic incident spectrum was simulated with the tungsten anode spectral model using the interpolating polynomials (TASMIP) code and carefully calibrated to match the x-ray tube in this study. Experiments were performed on a Cadmium-Zinc-Telluride (CZT) photon-counting detector with five energy thresholds. Energy bins were adjusted to evenly distribute the recorded counts above the noise floor. BR12 phantoms of various thicknesses were used for calibration. A nonlinear function was selected to fit the count correlation between the simulated and the measured spectra in the calibration process. To evaluate the proposed spectral distortion correction method, an empirical fitting derived from the calibration process was applied on the raw images recorded for polymethyl methacrylate (PMMA) phantoms of 8.7, 48.8, and 100.0 mm. Both the corrected counts and the effective attenuation coefficient were compared to the simulated values for each of the five energy bins. The feasibility of applying the proposed method to quantitative material decomposition was tested using a dual-energy imaging technique with a three-material phantom that consisted of water, lipid, and protein. The performance of the spectral distortion correction method was quantified using the relative root-mean-square (RMS) error with respect to the expected values from simulations or areal analysis of the decomposition phantom. Results: The implementation of the proposed method reduced the relative RMS error of the output counts in the five energy bins with respect to the simulated incident counts from 23.0%, 33.0%, and 54.0% to 1.2%, 1.8%, and 7.7% for 8.7, 48.8, and 100.0 mm PMMA phantoms, respectively. The accuracy of the effective attenuation coefficient of PMMA estimate was also improved with the proposed spectral distortion correction. Finally, the relative RMS error of water, lipid, and protein decompositions in dual-energy imaging was significantly reduced from 53.4% to 6.8% after correction was applied. Conclusions: The study demonstrated that dramatic distortions in the recorded raw image yielded from a photon-counting detector could be expected, which presents great challenges for applying the quantitative material decomposition method in spectral CT. The proposed semi-empirical correction method can effectively reduce these errors caused by various artifacts, including pulse pileup and charge sharing effects. Furthermore, rather than detector-specific simulation packages, the method requires a relatively simple calibration process and knowledge about the incident spectrum. Therefore, it may be used as a generalized procedure for the spectral distortion correction of different photon-counting detectors in clinical breast CT systems.

Ding Huanjun; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

2012-04-15T23:59:59.000Z

186

EFFECT OF ORBIT DISTORTIONS LAND BETATRON TUNE ON THE RHIC POLARIZED BEAM.  

Science Conference Proceedings (OSTI)

Polarized protons have been stored and accelerated in RHIC from G{sub {gamma}} = 46.5 to 60 during Run2000 with only one Siberian snake installed. We simulated with the spin tracking code Spink the behavior of polarized protons, in particular the effect of closed orbit distortions and betatron tune variation on the spin dynamics. According to simulation results, closed orbit and tune effects will be translated into requirements for the tune and orbit correction systems for the RHIC polarized proton Run2001, when both Siberian snakes will be available.

LUCCIO,A.U.; PILAT,F.; PTITSYN,V.

2001-06-18T23:59:59.000Z

187

Measurement and modeling of mirror distortion in a high power FEL  

Science Conference Proceedings (OSTI)

Mirror heating in a high power FEL can alter the optical mode and affect the gain of the laser. This can lead to a large reduction of the laser power from ideal values. Measurements of the power and mode size in the Jefferson Lab IR Demo laser have shown clear evidence of mirror distortion at high average power leading (up to 17 kW incident on the mirrors and over 40 W absorbed per mirror). The measurements and comparisons with modeling will be presented. Both steady state and transient analyses and measurements are considered.

Benson, S.; Neil, G.; Michelle D. Shinn

2000-01-01T23:59:59.000Z

188

Power frequency communication on long feeders and high levels of harmonic distortion  

SciTech Connect

TWACS is a unique Power Frequency Communication (PFC) technology. The power voltage is modulated at the substation bus for outbound communication and inbound communication from a remote transponder is accomplished by drawing precisely controlled current pulses which are detectable at the distribution substation. The propagation characteristics of the TWACS signal and the frequency characteristics of the signal detector make it possible to communicate over very long distribution feeders and provide a high degree of immunity against harmonic distortions of the power system voltage and current.

Mak, S.T.; Maginnis, R.L. [Distribution Control Systems, Inc., Hazelwood, MO (United States)

1995-10-01T23:59:59.000Z

189

Actively Star Forming Elliptical Galaxies at Low Redshifts in the Sloan Digital Sky Survey  

E-Print Network (OSTI)

We report discovery of actively star forming elliptical galaxies in a morphologically classified sample of bright galaxies at a low redshift obtained from the Sloan Digital Sky Survey. The emission lines of these galaxies do not show the characteristics of active galactic nuclei, and thus their strong H$\\alpha$ emission is ascribed to star formation with a rate nearly as high as that is seen in typical late spiral galaxies. This is taken as evidence against the traditional view that all elliptical galaxies formed early and now evolve only passively. The frequency of such star forming elliptical galaxies is a few tenths of a percent in the sample, but increases to 3% if we include active S0 galaxies. We may identify these galaxies as probable progenitors of so-called E+A galaxies that show the strong Balmer absorption feature of A stars superimposed on an old star population. The approximate match of the abundance of active elliptical plus S0 galaxies with that of E+A galaxies indicates that the duration of such late star formation episodes is of the order of $\\gsim 1$ Gyr. If we interpret these galaxies as new additions to the early-type galaxy population, and if we assume a power law for their number evolution, the abundance of early-type galaxies at $z=1$ is about 30% less than that at $z=0$.

Masataka Fukugita; Osamu Nakamura; Edwin L. Turner; Joe Helmboldt; R. C. Nichol

2003-12-19T23:59:59.000Z

190

Estimation of compact binary coalescense rates from short gamma-ray burst redshift measurements  

E-Print Network (OSTI)

Short gamma-ray bursts are believed to originate from the merger of two compact objects. If this scenario is correct, these bursts will be accompanied by the emission of strong gravitational waves, detectable by current or planned GW detectors, such as LIGO and Virgo. No detection of a gravitational wave has been made up to date. In this paper I will use a set of observed redshift measurements of short gamma-ray bursts to fit a model in order to determine the rate of such merger events in the nearby universe. Various corrections will be included in that calculation, as the field-of-view of the satellite missions, the beaming factors of gamma-ray bursts and other parameters. The computed rate estimations will be compared to other rate estimations, based on observations on binary neutron stars and population synthesis models. Given the upper limit established by LIGO/Virgo measurements, it is possible to draw conclusions on the beaming angle of gamma-ray bursts.

Alexander Dietz

2010-11-09T23:59:59.000Z

191

A 250 GHz Survey of High Redshift QSOs from the Sloan Digital Sky Survey  

E-Print Network (OSTI)

We present observations at 250 GHz (1.2 mm), 43 GHz, and 1.4 GHz of a sample of 41 QSOs at z > 3.7 found in the Sloan Digital Sky Survey. We detect 16 sources with a 250 GHz flux density greater than 1.4 mJy. The combination of centimeter and millimeter wavelength observations indicates that the 250 GHz emission is most likely thermal dust emission. Assuming a dust temperature of 50 K, the implied dust masses for the 16 detected sources are in the range 1.5e8 to 5.9e8 Msun, and the dust emitting regions are likely to be larger than 1 kpc in extent. The radio-through-optical spectral energy distributions for these sources are within the broad range defined by lower redshift, lower optical luminosity QSOs. We consider possible dust heating mechanisms, including UV emission from the active nucleus (AGN) and a starburst concurrent with the AGN, with implied star formation rates between 500 and 2000 Msun/year.

Carilli, C L; Rupen, M P; Fan, X; Strauss, M A; Menten, K M; Kreysa, E; Schneider, D P; Bertarini, A; Yun, M S; Zylka, R; Fan, Xiaohui; Strauss, Michael A.; Schneider, Donald P.

2001-01-01T23:59:59.000Z

192

Constraining large scale HI bias using redshifted 21-cm signal from the post-reionization epoch  

E-Print Network (OSTI)

In the absence of complex astrophysical processes that characterize the reionization era, the 21-cm emission from neutral hydrogen (HI) in the post-reionization epoch is believed to be an excellent tracer of the underlying dark matter distribution. Assuming a background cosmology, it is modelled through (i) a bias function b(k,z), which relates HI to the dark matter distribution and (ii) a mean neutral fraction (x_{HI}) which sets its amplitude. In this paper, we investigate the nature of large scale HI bias. The post-reionization HI is modelled using gravity only N-Body simulations and a suitable prescription for assigning gas to the dark matter halos. Using the simulated bias as the fiducial model for HI distribution at z\\leq 4, we have generated a hypothetical data set for the 21-cm angular power spectrum (C_{l}) using a noise model based on parameters of an extended version of the GMRT. The binned C_{l} is assumed to be measured with SNR \\gtrsim 4 in the range 400 \\leq l \\leq 8000 at a fiducial redshift z...

Sarkar, Tapomoy Guha; Majumdar, Suman; Choudhury, Tirthankar Roy

2011-01-01T23:59:59.000Z

193

The Luminosity Function and Mean Galaxy Density from the ESP galaxy Redshift Survey  

E-Print Network (OSTI)

We summarise the main results obtained over the last two years by the ESO Slice Project (ESP) redshift survey, concerning the luminosity function and mean density of galaxies, and their implications for the galaxy number counts at bright magnitudes. The bj-band luminosity function is characterised by a steep faint-end, which raises above a "global" Schechter fit for M_bj > -17 + 5log(h) and is well described by a power-law with slope ~ -1.6. This steepening is mostly produced by galaxies with emission lines, with a clear trend for galaxies with larger [OII] equivalent widths to show a steeper faint end (and a fainter M*). The normalization of the luminosity function is about a factor of 1.6 higher that that from the Stromlo-APM survey. We find that, in fact, the mean density can be seen to increase out to ~140/h Mpc. If we take this into account when computing the expected cumulative number counts from the observed luminosity function, we are able to reproduce the observed steep counts at bright (bj<17) magnitudes very accurately.

E. Zucca; G. Zamorani; P. Vettolani

1998-10-06T23:59:59.000Z

194

ON THE CORRELATION OF LOW-ENERGY SPECTRAL INDICES AND REDSHIFTS OF GAMMA-RAY BURSTS  

SciTech Connect

It was found by Amati et al. in 2002 that for a small sample of nine gamma-ray bursts (GRBs), more distant events appear to be systematically harder in the soft gamma-ray band. Here, we have collected a larger sample of 65 GRBs, whose time-integrated spectra are well established and can be well fitted with the so-called Band function. It is confirmed that a correlation between the redshifts (z) and the low-energy indices ({alpha}) of the Band function does exist, though it is a bit more scattered than the result of Amati et al. This correlation cannot be simply attributed to the effect of photon reddening. Furthermore, correlations between {alpha} and E {sub peak} (the peak energy in the {nu}F {sub {nu}} spectrum in the rest frame), {alpha} and E {sub iso} (the isotropic energy release), and {alpha} and L {sub iso} (the isotropic luminosity) are also found, which indicate that these parameters are somehow connected. The results may provide useful constraints on the physics of GRBs.

Geng, J. J.; Huang, Y. F., E-mail: hyf@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

2013-02-10T23:59:59.000Z

195

Exploring the chemical link between local ellipticals and their high-redshift progenitors  

E-Print Network (OSTI)

We present Keck/MOSFIRE K-band spectroscopy of the first mass-selected sample of galaxies at $z\\sim2.3$. Targets are selected from the 3D-HST Treasury survey. The six detected galaxies have a mean [NII]$\\lambda$6584/H\\alpha$ ratio of $0.27\\pm0.01$, with a small standard deviation of 0.05. This mean value is similar to that of UV-selected galaxies of the same mass. The mean gas-phase oxygen abundance inferred from the [NII]/H\\alpha$ ratios depends on the calibration method, and ranges from 12+log(O/H)$_{gas}=8.57$ for the {Pettini} & {Pagel} (2004) calibration to 12+log(O/H)$_{gas}= 8.87$ for the {Maiolino} {et al.} (2008) calibration. Measurements of the stellar oxygen abundance in nearby quiescent galaxies with the same number density indicate 12+log(O/H)$_{stars}= 8.95$, similar to the gas-phase abundances of the $z\\sim2.3$ galaxies if the {Maiolino} {et al.} (2008) calibration is used. This suggests that these high-redshift star forming galaxies may be progenitors of today's massive early-type galaxies...

Leja, Joel; Momcheva, Ivelina; Brammer, Gabriel; Skelton, Rosalind E; Whitaker, Katherine E; Andrews, Brett H; Franx, Marijn; Kriek, Mariska; van der Wel, Arjen; Bezanson, Rachel; Conroy, Charlie; Schreiber, Natascha Forster; Nelson, Erica; Patel, Shannon G

2013-01-01T23:59:59.000Z

196

Disk formation and the origin of clumpy galaxies at high redshift  

E-Print Network (OSTI)

Observations of high redshift galaxies have revealed a multitude of large clumpy rapidly star-forming galaxies. Their formation scenario and their link to present day spirals is still unknown. In this Letter we perform AMR simulations of disk formation in a cosmological context that are unrivaled in terms of mass and spatial resolution. We find that the so called "chain-galaxies" and "clump-clusters" are a natural outcome of early epochs of enhanced gas accretion from cold dense streams as well as tidally and ram-pressured stripped material from minor mergers and satellites. Through interaction with the hot halo gas, this freshly accreted cold gas settles into a large disk-like system, not necessarily aligned to an older stellar component, that undergoes fragmentation and subsequent star formation, forming large clumps in the mass range 10^7-10^9 M_sun. Galaxy formation is a complex process at this important epoch when most of the central baryons are being acquired through a range of different mechanisms - we...

Agertz, Oscar; Moore, Ben

2009-01-01T23:59:59.000Z

197

Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on its Redshift  

SciTech Connect

We report the first detection of very-high-energy (VHE) gamma-ray emission above 140GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140GeV measured by VERITAS is well described by a power law with a photon index of 3.8 {+-}0.5{sub stat} {+-} 0.3{sub syst} and a flux normalization at 200 GeV of (5.1 {+-} 0.9{sub stat} {+-} 0.5{sub syst}) x 10{sup -11} TeV{sup -1} cm{sup -2} s{sup -1}, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.

Acciari, V.A.; /Harvard-Smithsonian Ctr. Astrophys.; Aliu, E.; /Delaware U., Bartol Inst.; Arlen, T.; /UCLA; Aune, T.; /UC, Santa Cruz; Bautista, M.; /McGill U.; Beilicke, M. /Washington U., St. Louis; Benbow, W.; /Harvard-Smithsonian Ctr. Astrophys.; Bottcher, M.; /Ohio U.; Boltuch, D.; /Delaware U., Bartol Inst.; Bradbury, S.M.; /Leeds U.; Buckley, J.H.; /Washington U., St. Louis; Bugaev, V.; /Washington U., St. Louis; Byrum, K.; /Argonne; Cannon, A.; /University Coll., Dublin; Cesarini, A.; /Natl. U. of Ireland, Galway; Chow, Y.C.; /UCLA; Ciupik, L.; /Roosevelt U., Chicago; Cogan, P.; /McGill U.; Cui, W.; /Purdue U.; Duke, C.; /Grinnell Coll.; Falcone, A.; /Penn State U. /Purdue U. /Utah U. /Roosevelt U., Chicago /Harvard-Smithsonian Ctr. Astrophys. /Purdue U. /Natl. U. of Ireland, Galway /Utah U. /University Coll., Dublin /McGill U. /Roosevelt U., Chicago /McGill U. /Delaware U., Bartol Inst. /Utah U. /Chicago U., EFI /Iowa State U. /Roosevelt U., Chicago /DePauw U. /Utah U. /Pittsburg State U. /Washington U., St. Louis /Iowa State U. /Natl. U. of Ireland, Galway /Utah U. /McGill U. /Washington U., St. Louis /McGill U. /McGill U. /Purdue U. /Anderson U. /Galway-Mayo Inst. of Tech. /Iowa State U. /UCLA; /more authors..

2012-04-05T23:59:59.000Z

198

Sub-L* Galaxies at Redshifts z~4, 3, and 2: Their UV Luminosity Function and Luminosity Density  

E-Print Network (OSTI)

We use very deep (R_lim=27) UGRI imaging to study the evolution of the faint end of the UV-selected galaxy luminosity function from z~4 to z~2. We find that the luminosity function evolves with time and that this evolution is differential with luminosity: the number of sub-L* galaxies increases from z~4 to z~3 by at least a factor of 2.3, while the bright end of the LF remains unchanged. Potential systematic biases restrict our ability to draw strong conclusions at lower redshifts, z~2, but we can say that the number density of sub-L* galaxies at z~2.2 is at least as high as it is at z~3. Turning to the UV luminosity density of the Universe, we find that the luminosity density starts dropping with increasing redshift already beginning at z=3 (earlier than recently thought - Steidel et al. 1999) and that this drop is dominated by the same sub-L* galaxies that dominate the evolution of the LF. This differential evolution of the luminosity function suggests that differentially comparing key diagnostics of dust, stellar populations, etc. as a function of z and L should let us isolate the key mechanisms that drive galaxy evolution at high redshift.

Marcin Sawicki; David Thompson

2005-09-15T23:59:59.000Z

199

The $z=0.558$ absorption system towards PKS 0118-272: A candidate Damped Ly $?$ system at low redshift  

E-Print Network (OSTI)

We present a spectroscopic and imaging study of the z=0.558 MgII absorption system towards the BL Lac PKS 0118-272. At the absorber redshift we detect lines of the low ionization species MgI, MgII, CaII, TiII, MnII, and FeII. The column densities of these species are typical of the interstellar gas in the disk of the Galaxy. By assuming dust-free gas with solar abundances we infer N(HI) > 2.5 x 10^19 cm^-2. The high value of this conservative lower limit indicates that the absorber is a Damped Ly alpha system. We find [Ti/Fe] = +0.3, in agreement with [Ti/Fe] measurements in DLA absorbers, but [Mn/Fe] = +0.4, at variance with the values [Mn/Fe]2), the z=0.558 absorber seems to originate in a galaxy that has already attained the abundances and dust content of present-day disk galaxies. The analysis of our imaging data lends support to the presence of an intervening galaxy. After careful subtraction of the BL Lac image, an object at 1.6 arcsec from PKS 0118-272 is detected. At the absorber redshift the projected distance (14 h_50^-1 kpc) and the absolute magnitude (M_R ~ -22.3) of this companion are consistent with those found for galaxies associated with low-redshift DLA systems.

G. Vladilo; M. Centurion; R. Falomo; P. Molaro

1997-10-02T23:59:59.000Z

200

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Luminosity and Color Dependence and Redshift Evolution  

E-Print Network (OSTI)

We measure the luminosity and color dependence and the redshift evolution of galaxy clustering in the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Ninth Data Release. We focus on the projected two-point correlation function (2PCF) of subsets of its CMASS sample, which includes about 260,000 galaxies over ~3,300 sq. deg in the redshift range 0.43redshift bins, with more luminous and redder galaxies generally exhibiting stronger clustering and steeper 2PCF. The color dependence is also clearly seen for galaxies within the red sequence, consistent with the behavior o...

Guo, Hong; Zheng, Zheng; Weinberg, David H; Berlind, Andreas A; Blanton, Michael; Chen, Yanmei; Eisenstein, Daniel J; Ho, Shirley; Kazin, Eyal; Manera, Marc; Maraston, Claudia; McBride, Cameron K; Nuza, Sebastian E; Padmanabhan, Nikhil; Parejko, John K; Percival, Will J; Ross, Ashley J; Ross, Nicholas P; Samushia, Lado; Sanchez, Ariel G; Schlegel, David J; Schneider, Donald P; Skibba, Ramin A; Swanson, Molly E C; Tinker, Jeremy L; Tojeiro, Rita; Wake, David A; White, Martin; Bahcall, Neta A; Bizyaev, Dmitry; Brewington, Howard; Bundy, Kevin; da Costa, Luiz N A; Ebelke, Garrett; Malanushenko, Viktor; Malanushenko, Elena; Oravetz, Daniel; Rossi, Graziano; Simmons, Audrey; Snedden, Stephanie; Streblyanska, Alina; Thomas, Daniel

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Sculpting space through sound  

E-Print Network (OSTI)

How does one experience space? What kind of information do humans collect in the process of constructing space in their mind? How does one begin to understand volume, light, texture, material, smell and sense of space? The ...

Nakagawa, Junko, 1975-

2002-01-01T23:59:59.000Z

202

Space Solar Power Program  

DOE Green Energy (OSTI)

Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

Arif, H.; Barbosa, H.; Bardet, C.; Baroud, M.; Behar, A.; Berrier, K.; Berthe, P.; Bertrand, R.; Bibyk, I.; Bisson, J.; Bloch, L.; Bobadilla, G.; Bourque, D.; Bush, L.; Carandang, R.; Chiku, T.; Crosby, N.; De Seixas, M.; De Vries, J.; Doll, S.; Dufour, F.; Eckart, P.; Fahey, M.; Fenot, F.; Foeckersperger, S.; Fontaine, J.E.; Fowler, R.; Frey, H.; Fujio, H.; Gasa, J.M.; Gleave, J.; Godoe, J.; Green, I.; Haeberli, R.; Hanada, T.; Ha

1992-08-01T23:59:59.000Z

203

Standard test method for measurement of roll wave optical distortion in heat-treated flat glass  

E-Print Network (OSTI)

1.1 This test method is applicable to the determination of the peak-to-valley depth and peak-to-peak distances of the out-of-plane deformation referred to as roll wave which occurs in flat, heat-treated architectural glass substrates processed in a heat processing continuous or oscillating conveyance oven. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This test method does not address other flatness issues like edge kink, ream, pocket distortion, bow, or other distortions outside of roll wave as defined in this test method. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

204

Lattice distortions in layered type arsenides LnTAs{sub 2} (Ln=La-Nd, Sm, Gd, Tb; T=Ag, Au): Crystal structures, electronic and magnetic properties  

SciTech Connect

The lanthanide coinage-metal diarsenides LnTAs{sub 2} (Ln=La, Ce-Nd, Sm; T=Ag, Au) have been reinvestigated and their structures have been refined from single crystal X-ray data. Two different distortion variants of the HfCuSi{sub 2} type are found: PrAgAs{sub 2}, NdAgAs{sub 2}, SmAgAs{sub 2}, GdAgAs{sub 2}, TbAgAs{sub 2}, NdAuAs{sub 2} and SmAuAs{sub 2} crystallize as twofold superstructures in space group Pmcn with the As atoms of their planar layers forming zigzag chains, whereas LaAgAs{sub 2}, CeAgAs{sub 2} and PrAuAs{sub 2} adopt a fourfold superstructure (space group Pmca) with cis-trans chains of As atoms. The respective atomic positions can be derived from the HfCuSi{sub 2} type by group-subgroup relations. The compounds with zigzag chains of As atoms exhibit metallic behaviour while those with cis-trans chains are semiconducting as measured on powder pellets. The majority of the compounds including 4f elements show antiferromagnetic ordering at T{sub N}<20 K. - Text3: Zigzig vs. cis-trans.

Rutzinger, D.; Bartsch, C. [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany); Doerr, M. [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Rosner, H. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Str. 40, D-01187 Dresden (Germany); Neu, V. [IFW Dresden, Institut fuer metallische Werkstoffe, Helmholtzstr. 20, D-01069 Dresden (Germany); Doert, Th., E-mail: thomas.doert@chemie.tu-dresden.d [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany); Ruck, M. [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany)

2010-03-15T23:59:59.000Z

205

Electric:SpaceCharge  

Science Conference Proceedings (OSTI)

... OOF2: The Manual. Electric:SpaceCharge. Prev, 6.4.1. Material Properties, Next. Name. Electric:SpaceCharge — Spatial charge density. Details. ...

2013-07-05T23:59:59.000Z

206

Exhibit Space Reservation (PDF)  

Science Conference Proceedings (OSTI)

Zip: Country: E-mail Address: Telephone Number: Fax Number: Signature: Date: Please reserve _____ (quantity) 10' x 10' space at $1,100 each. Exhibit space ...

207

Chemically consistent evolution of galaxies: II. Spectrophotometric evolution from zero to high redshift  

E-Print Network (OSTI)

We present a new generation of chemically consistent evolutionary synthesis models for galaxies of various spectral types from E through Sd. The models follow the chemical enrichment of the ISM and take into account the increasing initial metallicity of successive stellar generations using recently published metallicity dependent stellar evolutionary isochrones, spectra and yields. Our first set of closed-box 1-zone models does not include any spatial resolution or dynamics. For a Salpeter initial mass function (IMF) the star formation rate(SFR) and its time evolution are shown to successfully parameterise spectral galaxy types E, ..., Sd. We show how the stellar metallicity distribution in various galaxy types build up with time to yield after $\\sim 12$ Gyr agreement with stellar metallicity distributions observed in our and other local galaxies. The models give integrated galaxy spectra over a wide wavelength range (90.9\\AA - 160$\\mu$m), which for ages of $\\sim 12$ Gyr are in good agreement not only with observed broad band colours but also with template spectra for the respective galaxy types. Using filter functions for Johnson-Cousins, as well as for HST broad band filters in the optical and Bessel & Brett's NIR filter system, we calculate the luminosity and colour evolution of model galaxies over a Hubble time. Including a standard cosmological model and the attenuation by intergalactic hydrogen we present evolutionary and cosmological corrections as well as apparent luminosities in various filters over the redshift range from z $\\sim 5$ to the present for our galaxy types and compare to earlier models using single (=solar) metallicity input physics only. We also present a first comparison of our cc models to HDF data.(Abridged abstract)

Jens Bicker; Uta Fritze - v. Alvensleben; Claudia S. Moeller; Klaus J. Fricke

2003-09-25T23:59:59.000Z

208

The ESO Slice Project [ESP] galaxy redshift survey: V. Evidence for a D=3 sample dimensionality  

E-Print Network (OSTI)

The issue of the approximate isotropy and homogeneity of the observable universe is one of the major topics in modern Cosmology: the common use of the Friedmann-Robertson-Walker [FWR] metric relies on these assumptions. Therefore, results conflicting with the ``canonical'' picture would be of the utmost importance. In a number of recent papers it has been suggested that strong evidence of a fractal distribution with dimension D~2 exists in several samples, including Abell clusters [ACO] and galaxies from the ESO Slice Project redshift survey [ESP].Here we report the results of an independent analysis of the radial density run,N(ESP and ACO data. For the ESP data the situation is such that the explored volume, albeit reasonably deep, is still influenced by the presence of large structures. Moreover, the depth of the ESP survey (zESP sample is D~3, and the value $D = 2$ is always excluded at the level of at least five (bootstrap) standard deviations. The only way in which we reproduce D~2 is by both unphysically ignoring the galaxy k-correction and using Euclidean rather than FRW cosmological distances. In the cluster case the problems related to the choice of metrics and k-correction are much lessened, and we find that ACO clusters have D_{ACO} = 3.07 +- 0.18 and D_{ACO} = 2.93 +- 0.15 for richness class R \\geq 1 and R \\geq 0, respectively. Therefore D=2 is excluded with high significance also for the cluster data.

R. Scaramella; L. Guzzo; G. Zamorani; E. Zucca; C. Balkowski; A. Blanchard; A. Cappi; V. Cayatte; G. Chincarini; C. Collins; A. Fiorani; D. Maccagni; H. MacGillivray; S. Maurogordato; R. Merighi; M. Mignoli; D. Proust; M. Ramella; G. M. Stirpe; G. Vettolani

1998-03-03T23:59:59.000Z

209

Luminosity dependent clustering of star-forming BzK galaxies at redshift 2  

E-Print Network (OSTI)

We use the BzK color selection proposed by Daddi et al. (2004) to obtain a sample of 1092 faint star-forming galaxies (hereafter sBzKs) from 180 arcmin^2 in the Subaru Deep Field. This sample represents star-forming galaxies at 1.4 ACF) of these sBzKs to be w(theta) = (0.58 +- 0.13) x theta["]^{-0.8} and translate the amplitude into the correlation length assuming a reasonable redshift distribution. The resulting value, r0 = 3.2^{+0.6}_{-0.7} h^{-1} Mpc, suggests that our sBzKs reside in haloes with a typical mass of 2.8 x 10^{11} Msun. Combining this halo mass estimate with those for brighter samples of Kong et al. (2006), we find that the mass of dark haloes largely increases with K brightness, a measure of the stellar mass. Comparison with other galaxy populations suggests that faint sBzKs (K(AB)<23.2) and Lyman Break Galaxies at z ~ 2 are similar populations hosted by relatively low-mass haloes, while bright sBzKs (K(AB)<21) reside in haloes comparable to or more massive than those of Distant Red Galaxies and Extremely Red Objects. Using the extended Press-Schechter formalism, we predict that present-day descendants of haloes hosting sBzKs span a wide mass range depending on K brightness, from lower than that of the Milky Way up to those of richest clusters.

Masao Hayashi; Kazuhiro Shimasaku; Kentaro Motohara; Makiko Yoshida; Sadanori Okamura; Nobunari Kashikawa

2007-01-23T23:59:59.000Z

210

On the temporal variability classes found in long gamma-ray bursts with known redshift  

E-Print Network (OSTI)

Based on the analysis of a small sample of BATSE and Konus gamma-ray bursts (GRBs) with know redshift it has been reported that the width of the autocorrelation function (ACF) shows a remarkable bimodal distribution in the rest-frame of the source. However, the origin of these two well-separated ACF classes remains unexplained.We complement previous ACF analysis studying the corresponding power density spectra (PDS). With the addition of Beppo-SAX data and taken advantage of its broad-band capability, we not only increase the burst sample but we extend the analysis to X-ray energies. The rest-frame PDS analysis at gamma-ray energies shows that the two ACF classes are not simply characterised by a different low frequency cut-off, but they have a distinct variability as a whole in the studied frequency range. Both classes exhibit average PDS with power-law behaviour at high frequencies (f' > 0.1 Hz) but significantly different slopes, with index values close to those of Brownian (-2) and Kolmogorov (-5/3) spectra for the narrow and broad classes respectively. The latter spectrum presents an additional PDS component, a low-frequency noise excess with a sharp cut-off. At X-ray energies we find the power-law index unchanged for the broad class, but a significantly steeper slope in the narrow case (~ -3). We interpret this as an indication that the broad class bursts have weaker spectral evolution than the narrow ones, as suggested also by our analysis of the ACF energy dependence. The low and high frequency PDS components may then arise from two radiating regions involving different emission mechanisms.

L. Borgonovo; F. Frontera; C. Guidorzi; E. Montanari; L. Vetere; P. Soffitta

2007-01-31T23:59:59.000Z

211

Lack of a Jahn-Teller Distortion in La1-xSrxCoO3 Determined by EXAFS and  

NLE Websites -- All DOE Office Websites (Extended Search)

Lack of a Jahn-Teller Distortion in Lack of a Jahn-Teller Distortion in La1-xSrxCoO3 Determined by EXAFS and Neutron PDF Studies The transition metal oxides exhibit a wide range of interesting properties, of which superconductivity in the copper oxides and colossal magnetoresistance in the manganese oxides are perhaps the best known. However, the strange magnetic behavior of several cobalt oxides is another example of these unusual properties, although not yet as intensively studied. The cobaltite system La1-xSrxCoO3 (LSCO) has a rich temperature-concentration phase diagram with anti-ferromagnetism and insulating behavior at low Sr concentrations, and ferromagnetism and metallic behavior at higher concentrations. The magnetism for the end compound LaCoO3 (LCO) is particularly unusual; it has no Co spin magnetic moment at low T (and is diamagnetic). As T increases from 4K, the magnetic susceptibility increases dramatically up to roughly 100K, and then decreases as T is increased to 300K. This behavior has been attributed to Co+3 having several different spin configurations. Initially only two were considered, a low spin state (LS, S=0) that is not magnetic and a high spin state (HS, S=2) that is strongly magnetic. In the '90s a third, intermediate spin configuration (IS, S=1) was proposed by Potze, et al. and Korotin, et al; this configuration should result in a distortion of the CoO6 octahedra (called a Jahn-Teller (JT) distortion). In the late '90s, Louca et al. reported neutron PDF results indicating a distorted Co-O environment, comparable to the Mn-O distortions observed in the similar manganite systems La1-yCayMnO3 (LCMO) and La1-zSrzMnO3 (LSMO). However, to date, these neutron PDF data for the cobaltites are the only structural results that support a JT distortion. While some recent experimental results are argued to be consistent with a large Co-O JT distortion and its associated IS state, many others appear to be inconsistent with such an interpretation. Our group at UC Santa Cruz, therefore took a closer look at the possibility of a JT distortion of the CoO6 octahedra, using a combination of the EXAFS and neutron PDF techniques; here we focus on the Co K-edge EXAFS results, for data collected at SSRL.

212

The Efficacy of Profile Matching as a Means of Controlling for the Effects of Response Distortion on Personality Measures  

E-Print Network (OSTI)

Researchers and practitioners continue to be concerned about the magnitude, extent, and effects of response distortion when self-report personality measures are used in high-stakes testing. One method for mitigating response distortion that has not received much empirical attention is profile matching. Profile matching assesses the fit between test-takers’ predictor profiles and a standard profile which represents an ideal or high performing employee’s profile. Since profile matching assesses fit, it can capture nonlinear effects. Furthermore, high predictor scores are not necessarily associated with higher criterion scores. Test–takers who distort their responses by choosing inaccurately extreme response options may improve their chances of being hired if a linear model is used, but this approach is unlikely to be effective if a profile matching strategy is used as long as the standard profile is unknown to the test-takers. As such, the primary objective of the present study was to examine the extent to which profile matching may alleviate concerns about response distortion. A secondary objective was to examine characteristics of the standard profile that are associated with the efficacy of this approach. The present study compared the effects of response distortion on personality test scores, and their criterion-related validity in predicting tenure, based on a linear composite and a profile fit score. The present study used data from 996 applicants who completed a personality test in a high-stakes testing context. Missing data were imputed for a subset of applicants who did not complete two response distortion scales. As such, the results provided an initial proof-of-concept of the effectiveness of profile matching as a personnel decision-making strategy using a blend of real and simulated data. The results suggest that profile fit scores are less related to response distortion and display higher criterion-related validity than linear composite scores. However, the difference in criterion-related validity could not be attributed to response distortion. The results further suggest that the amount of scatter in the standard profile is negatively associated with the profile fit score’s susceptibility to response distortion and positively related to criterion-related validity.

Glaze, Ryan 1983-

2012-12-01T23:59:59.000Z

213

In Outer Space without a Space Suit?  

E-Print Network (OSTI)

The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen is lacking. In this case the main problem is how to satiate human blood with oxygen and delete carbonic acid gas (carbon dioxide). The proposed system would enable a person to function in outer space without a space suit and, for a long time, without food. That is useful also in the Earth for sustaining working men in an otherwise deadly atmosphere laden with lethal particulates (in case of nuclear, chemical or biological war), in underground confined spaces without fresh air, under water or a top high mountains above a height that can sustain respiration.

Alexander Bolonkin

2008-06-24T23:59:59.000Z

214

General Transformations of Space and Time according to Aether Theory  

E-Print Network (OSTI)

Assuming the existence of a preferred aether frame and the anisotropy of the one-way speed of light in platforms different from the aether frame, we derive the space and time transformations relative to bodies moving in any direction of space and not only in the direction of the common x-axis of the co-ordinate systems under consideration. Taking for granted length contraction and clock retardation, we show that the experimental space-time transformations result from measurement distortions due to the fact that the length of the rods and the frequency of the clocks, used for the measure, do not have a constant value as a result of their motion through the aether, and because the standard synchronization procedures are affected by a synchronism discrepancy effect. When the motion of bodies is aligned along the common x-axis, the transformations assume the same mathematical form as the conventional transformations. However, their meaning is quite different because they have been derived on the basis of very different assumptions, and they arise from the measurement distortions mentioned above. Therefore they conceal hidden variables which are the true transformations.

Joseph Levy

2010-03-09T23:59:59.000Z

215

Transformations of Grassman Spaces  

E-Print Network (OSTI)

This is a version of a part of the book ``Transformations of Grassman Spaces'' (in progress). We study transformations of Grassman spaces preserving certain geometrical constructions related to buildings. The next part will be devoted to Grassman spaces associated with polar spaces.

Mark Pankov

2004-04-05T23:59:59.000Z

216

Space System Architecture  

E-Print Network (OSTI)

Final Report of SSPARC: the Space Systems, Policy, and Architecture Research Consortium (Thrust II and III)

McManus, Dr. Hugh

217

Non-Gaussianity as a Probe of the Physics of the Primordial Universe and the Astrophysics of the Low Redshift Universe  

SciTech Connect

A new and powerful probe of the origin and evolution of structures in the Universe has emerged and been actively developed over the last decade. In the coming decade, non-Gaussianity, i.e., the study of non-Gaussian contributions to the correlations of cosmological fluctuations, will become an important probe of both the early and the late Universe. Specifically, it will play a leading role in furthering our understanding of two fundamental aspects of cosmology and astrophysics: (1) The physics of the very early universe that created the primordial seeds for large-scale structures, and (2) The subsequent growth of structures via gravitational instability and gas physics at later times. To date, observations of fluctuations in the Cosmic Microwave Background (CMB) and the Large-Scale Structure of the Universe (LSS) have focused largely on the Gaussian contribution as measured by the two-point correlations (or the power spectrum) of density fluctuations. However, an even greater amount of information is contained in non-Gaussianity and a large discovery space therefore still remains to be explored. Many observational probes can be used to measure non-Gaussianity, including CMB, LSS, gravitational lensing, Lyman-{alpha} forest, 21-cm fluctuations, and the abundance of rare objects such as clusters of galaxies and high-redshift galaxies. Not only does the study of non-Gaussianity maximize the science return from a plethora of present and future cosmological experiments and observations, but it also carries great potential for important discoveries in the coming decade.

Komatsu, E.; /Texas U. /Tokyo U.; Afshordi, N.; /Perimeter Inst. Theor. Phys.; Bartolo, N.; /Padua U.; Baumann, D.; /Harvard U.; Bond, J.R.; /Toronto U.; Buchbinder, E.I.; /Perimeter Inst. Theor. Phys.; Byrnes, C.T.; /Heidelberg U.; Chen, Xingang; /MIT; Chung, D.J.H.; /Wisconsin U., Madison; Cooray, A.; /UC, Irvine; Creminelli, P.; /ICTP, Trieste; Dalal, N.; /Toronto U.; Dore, O.; /Toronto U.; Easther, R.; /Yale U.; Frolov, A.V.; /Simon Fraser U.; Gorski, K.M.; /Warsaw U.; Khoury, J.; /Pennsylvania U.; Kinney, W.H.; /SUNY, Buffalo; Kofman, L.; /Toronto U.; Koyama, K.; /Portsmouth U.; Leblond, L.; /Texas A-M /Princeton U. /Queen Mary, U. of London /Cambridge U., DAMTP /Columbia U. /Stanford U., Phys. Dept. /Lancaster U. /Princeton, Inst. Advanced Study /Padua U. /INFN, Padua /Cornell U., Phys. Dept. /Toronto U. /Tokyo U. /Pennsylvania U. /Princeton, Inst. Advanced Study /Cambridge U. /INFN, Padua /CERN /Antonio Narino U. /Santander Industrial U. /Kyoto U. /New York U. /Cambridge U., DAMTP /Saclay, SPhT /LBL, Berkeley /Zurich U. /Princeton, Inst. Advanced Study /Queen Mary, U. of London /Cambridge U., DAMTP /Stanford U., Phys. Dept. /SLAC /UC, Berkeley /Cambridge U. /Landau Inst. /Princeton U. /Tokyo U. /MIT /Perimeter Inst. Theor. Phys. /Barcelona, IEEC /Illinois U., Urbana /Portsmouth U. /Texas U. /Perimeter Inst. Theor. Phys. /Harvard U. /Harvard U.

2011-11-14T23:59:59.000Z

218

Correlation energies in distorted 3d-t{sub 2g} perovskite oxides  

Science Conference Proceedings (OSTI)

Using an effective low-energy Hamiltonian derived from the first-principles electronic structure calculations for the narrow t{sub 2g} bands of YTiO{sub 3}, LaTiO{sub 3}, YVO{sub 3}, and LaVO{sub 3}, we evaluate the contributions of the correlation energy E{sub c} to the stability of different magnetic structures that can be realized in these distorted perovskite oxides. We consider two approximations for E{sub c} that are based on regular perturbation theory expansion around a nondegenerate Hartree-Fock ground state. One is the second order of perturbation theory, which allows comparing the effects of local and nonlocal correlations. The other is the local t-matrix approach, which allows treating some higher-order contributions to E{sub c}. The correlation effects systematically improve the agreement with the experimental data and additionally stabilize the experimentally observed G- and C-type antifer-romagnetic (AFM) structures in YVO{sub 3} and LaVO{sub 3}, although the absolute magnitude of the stabilization energy is sensitive to the level of approximations and is somewhat smaller in the t-matrix method. The nonlocal correlations additionally stabilize the ferromagnetic ground state in YTiO{sub 3} and the C-type AFM ground state in LaVO{sub 3}. Among two inequivalent transition-metal sites in the monoclinic structure, the local correlations are stronger at the sites with the least distorted environment. Limitations of the regular perturbation-theory expansion for LaTiO{sub 3} are also discussed.

Solovyev, I. V. [National Institute for Materials Science (NIMS), Computational Materials Science Center (CMSC) (Japan)], E-mail: solovyev.igor@nims.go.jp

2007-07-15T23:59:59.000Z

219

Correlation Energies in Distorted 3d-t2g Perovskite Oxides  

E-Print Network (OSTI)

Using an effective low-energy Hamiltonian derived from the first-principles electronic structure calculations for the narrow t2g bands of YTiO3, LaTiO3, YVO3, and LaVO3, we evaluate the contributions of the correlation energy (EC) to the stability of different magnetic structures, which can be realized in these distorted perovskite oxides. We consider two approximations for EC, which are based on the regular perturbation theory expansion around a nondegenerate Hartree-Fock ground state. One is the second order of perturbation theory, which allows us to compare the effects of local and nonlocal correlations. Another one is the local t-matrix approach, which allows us to treat some higher-order contributions to EC. The correlation effects systematically improve the agreement with the experimental data and additionally stabilize the experimentally observed G- and C-type antiferromagnetic (AFM) structures in YVO3 and LaVO3, though the absolute magnitude of the stabilization energy is sensitive to the level of approximations and somewhat smaller in the t-matrix method. The nonlocal correlations additionally stabilize the ferromagnetic ground state in YTiO3 and the C-type AFM ground state in LaVO3. Amongst two inequivalent transition-metal sites in the monoclinic structure, the local correlations are stronger at the sites with the least distorted environment. Limitations of the regular perturbation-theory expansion for LaTiO3 are also discussed. PACS: 71.10.-w; 71.15.Nc; 71.28.+d; 75.25.+z 1.

I. V. Solovyev

2006-01-01T23:59:59.000Z

220

run 873 - 7 September 1977, Rings 1 and 2 - 26 GeV, Orbit distortions due to sextupole fields with the low-beta insertion  

E-Print Network (OSTI)

run 873 - 7 September 1977, Rings 1 and 2 - 26 GeV, Orbit distortions due to sextupole fields with the low-beta insertion

Gourber, J P

1977-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Run 888 - 28 October 1977, Rings 1 and 2 - GeV, Orbit distortion due to sextupole fields with the low-beta insertion - part 2  

E-Print Network (OSTI)

Run 888 - 28 October 1977, Rings 1 and 2 - GeV, Orbit distortion due to sextupole fields with the low-beta insertion - part 2

Brand, K

1978-01-01T23:59:59.000Z

222

Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey  

E-Print Network (OSTI)

We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z \\lesssim 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04+1.61-0.95 % of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used t...

Dilday, Benjamin; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Filippenko, Alexei V; Frieman, Joshua A; Galbany, Lluis; Garnavich, Peter M; Goobar, Ariel; Hopp, Ulrich; Ihara, Yutaka; Jha, Saurabh W; Kessler, Richard; Lampeitl, Hubert; Marriner, John; Miquel, Ramon; Molla, Mercedes; Nichol, Robert C; Nordin, Jakob; Riess, Adam G; Sako, Masao; Schneider, Donald P; Sollerman, Jesper; Wheeler, J Craig; Ostman, Linda; Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Dan; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie

2010-01-01T23:59:59.000Z

223

Topological Test Spaces  

E-Print Network (OSTI)

A test space is the set of outcome-sets associated with a collection of experiments. This notion provides a simple mathematical framework for the study of probabilistic theories -- notably, quantum mechanics -- in which one is faced with incommensurable random quantities. In the case of quantum mechanics, the relevant test space, the set of orthonormal bases of a Hilbert space, carries significant topological structure. This paper inaugurates a general study of topological test spaces. Among other things, we show that any topological test space with a compact space of outcomes is of finite rank. We also generalize results of Meyer and Clifton-Kent by showing that, under very weak assumptions, any second-countable topological test space contains a dense semi-classical test space.

Alexander Wilce

2004-05-28T23:59:59.000Z

224

NSLS Committees | Space Committee  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Sciences Space Committee Charge Purpose The Photon Sciences Directorate (PS) Space Committee is convened by the PS Chief Operating Officer (COO) on an as-needed basis to...

225

Small Space Heaters  

Energy.gov (U.S. Department of Energy (DOE))

Small space heaters, also called portable heaters, are typically used when the main heating system is inadequate or when central heating is too costly to install or operate. Space heater capacities...

226

Flow Distortion by a Solent Sonic Anemometer: Wind Tunnel Calibration and Its Assessment for Flux Measurements over Forest and Field  

Science Conference Proceedings (OSTI)

Main flow distortion effects caused by the sonic probe (i.e., deflection and attenuation/amplification of the wind vector) as a function of the azimuth angle of the incoming flow were examined by means of wind tunnel measurements at four ...

A. Grelle; A. Lindroth

1994-12-01T23:59:59.000Z

227

Spectral restoration from low signal-to-noise, distorted NMR signals: application to hyphenated capillary electrophoresis-NMR  

E-Print Network (OSTI)

Spectral restoration from low signal-to-noise, distorted NMR signals: application to hyphenated capillary electrophoresis-NMR Yu Li,a,b Michael E. Lacey,b,c Jonathan V. Sweedler,b,c and Andrew G. Webba; revised 11 February 2003 Abstract In capillary electrophoresis separations coupled to NMR signal detection

Andrews, Anne M.

228

Neutron Tomography and Space  

E-Print Network (OSTI)

Propulsion Laboratory (JPL), uses a small Maxom motor on applications for manipulators in some of their space

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

229

Strongly exponential symmetric spaces  

E-Print Network (OSTI)

We study the exponential map of connected symmetric spaces and characterize, in terms of midpoints and of infinitesimal conditions, when it is a diffeomorphism, generalizing the Dixmier-Saito theorem for solvable Lie groups. We then give a geometric characterization of the (strongly) exponential solvable symmetric spaces as those spaces for which every triangle admits a unique double triangle. This work is motivated by Weinstein's quantization by groupoids program applied to symmetric spaces.

Yannick Voglaire

2013-03-24T23:59:59.000Z

230

Whither design space?  

Science Conference Proceedings (OSTI)

Design space exploration is a long-standing focus in computational design research. Its three main threads are accounts of designer action, development of strategies for amplification of designer action in exploration, and discovery of computational ... Keywords: Design Space Exploration, Knowledge Representation, Search, State Space, Typed Feature Structures

Robert F. Woodbury; Andrew L. Burrow

2006-04-01T23:59:59.000Z

231

Effect of two-phase natural circulation distortion on tube failure in steam boilers  

SciTech Connect

Two different cases of evaporator tube ruptures in power station boilers due to natural circulation distortion are presented. The first case discussed concerns a 110-MW/sub e/ unit boiler with bottom evaporation tubing inclined at 15/sup 0/ to the horizontal. At the high heat fluxes present in the furnace, subcooled boiling occurs in inclined tubes. For these inclinations an insufficient flow rate causes local heat transfer deficiencies due to vapor-water separation. The introduction of internally finned tubes eliminates local heat transfer deficiencies and prevents further tube failures. The second case is that of circulation interruption due to blowdown during start-up. The water level in the drum of this second 110-MW/sub e/ unit boiler was controlled by inlet header blowdown during start-up. Thus, natural circulation was interrupted, causing local overheating of evaporator tubing. The event was identified by an increase of the tube rupture frequency. After changing the blowdown procedure, the interruptions of natural circulation were avoided and the tube failure frequency decreased substantially.

Afgan, N.; Radovanovic, P.; Brajuskovic, B.

1987-01-01T23:59:59.000Z

232

Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey  

Science Conference Proceedings (OSTI)

We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z {approx}< 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04{sub -0.95}{sup +1.61}% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of r{sub V} = (2.69{sub -0.30-0.01}{sup +0.34+0.21}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} at a mean redshift of {approx} 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, r{sub V} (z) = A{sub p} x ((1+z)/(1+z{sub 0})){sup {nu}}, over the redshift range 0.0 < z < 0.3 with z{sub 0} = 0.21, results in A{sub p} = (3.43{sub -0.15}{sup +0.15}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} and {nu} = 2.04{sub -0.89}{sup +0.90}.

Dilday, Benjamin; /Rutgers U., Piscataway /Chicago U. /KICP, Chicago; Smith, Mathew; /Cape Town U., Dept. Math. /Portsmouth U.; Bassett, Bruce; /Cape Town U., Dept. Math. /South African Astron. Observ.; Becker, Andrew; /Washington U., Seattle, Astron. Dept.; Bender, Ralf; /Munich, Tech. U. /Munich U. Observ.; Castander, Francisco; /Barcelona, IEEC; Cinabro, David; /Wayne State U.; Filippenko, Alexei V.; /UC, Berkeley; Frieman, Joshua A.; /Chicago U. /Fermilab; Galbany, Lluis; /Barcelona, IFAE; Garnavich, Peter M.; /Notre Dame U. /Stockholm U., OKC /Stockholm U.

2010-01-01T23:59:59.000Z

233

Analysis of periodically-forced turbulence in the rapid distortion limit  

E-Print Network (OSTI)

Rapid Distortion Theory is used to perform calculations of unsteadily-forced initially isotropic turbulence so that the physics of such flows can be better understood. The results of these calculations show that there are three distinct regimes of physical behavior for the kind of turbulence that we are considering: (1) turbulence that is forced at a relatively low frequency in which the kinetic energy settles down to a constant value at later times, (2) turbulence that is forced at a slightly higher frequency in which the kinetic energy value oscillates for a time, but then increases dramatically, and (3) turbulence that is forced at a relatively high frequency in which the kinetic energy evolution exhibits a periodic behavior. To better understand the role of the rapid pressure-strain correlation, these results are also compared to Inertial Model results for the same set of forcing frequencies. The results of this comparison show that the rapid pressure plays a key role in determining the stability characteristics of unsteadily-forced turbulence. The evolution equation for kinetic energy is then used to propose a model that describes the behavior approximately in terms of a time lag between applied mean strain and the Reynolds stress. This model suggests that the different responses under the different frequencies of forcing correspond to different stress-strain time lags. Overall, then the results indicate that rapid pressure serves to create a time lag between applied stress and strain, and it is the extent of this time lag that causes turbulence to respond differently under various frequencies of forcing.

O'Neil, Joshua Robert

2004-12-01T23:59:59.000Z

234

Gymnastics in Phase Space  

SciTech Connect

As accelerator technology advances, the requirements on accelerator beam quality become increasingly demanding. Facing these new demands, the topic of phase space gymnastics is becoming a new focus of accelerator physics R&D. In a phase space gymnastics, the beam's phase space distribution is manipulated and precision tailored to meet the required beam qualities. On the other hand, all realization of such gymnastics will have to obey accelerator physics principles as well as technological limitations. Recent examples of phase space gymnastics include Emittance exchanges, Phase space exchanges, Emittance partitioning, Seeded FELs and Microbunched beams. The emittance related topics of this list are reviewed in this report. The accelerator physics basis, the optics design principles that provide these phase space manipulations, and the possible applications of these gymnastics, are discussed. This fascinating new field promises to be a powerful tool of the future.

Chao, Alexander Wu; /SLAC

2012-03-01T23:59:59.000Z

235

Berkeley Lab Space  

NLE Websites -- All DOE Office Websites (Extended Search)

Space Space Committee Charter Articles Presentations Feedback Contact Us ANNOUNCEMENTS Space Planning Advisory Committee (SPAC) The LBNL Space Planning Advisory Committee (SPAC) was chartered in January 2010 to help manage the growth, both in the short term as well as long term. Specifically, SPAC will recommend to senior laboratory management policies and procedures for the allocation and utilization of space and opportunities for increased efficiency. (For the complete charter, click here.)We welcome comments and suggestions. Our email is: SPAC@lbl.gov. SPAC (Space Planning Advisory Committee) SPAC Members Telephone Number Email Rich Diamond 510-486-4459 RCDiamond@lbl.gov Rich McClure 510-486-4486 RMMcClure@lbl.gov Diana Attia 510-486-7399 DMAttia@lbl.gov Rebecca Rishell 510-486-6689

236

Rigorous luminosity function determination in presence of a background: theory and application to two intermediate redshift clusters  

E-Print Network (OSTI)

In this paper we present a rigorous derivation of the luminosity function (LF) in presence of a background. Our approach is free from the logical contradictions of assigning negative values to positively defined quantities and avoid the use of incorrect estimates for the 68 % confidence interval (error bar). It accounts for Poisson fluctuations ignored in previous approaches and does not requires binning of the data. The method is extensible to more complex situations, does not require the existence of an environment--independent LF, and clarifies issues common to field LF derivations. We apply the method to two clusters of galaxies at intermediate redshift (z~0.3) with among the deepest and widest K_s observations ever taken. Finally, we point out short-comings of flip--flopping magnitudes.

S. Andreon; G. Punzi; A. Grado

2005-03-31T23:59:59.000Z

237

A glance at the host galaxy of high-redshift quasars using strong damped Lyman-alpha systems as coronagraphs  

E-Print Network (OSTI)

We searched quasar spectra from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) for the rare occurrences where a strong damped Lyman-alpha absorber (DLA) blocks the Broad Line Region emission from the quasar and acts as a natural coronagraph to reveal narrow Ly\\alpha\\ emission from the host galaxy. We define a statistical sample of 31 DLAs in Data Release 9 (DR9) with log N(HI) > 21.3 cm^-2 located at less than 1500 km s^-1 from the quasar redshift. In 25% (8) of these DLAs, a strong narrow Ly\\alpha\\ emission line is observed with flux ~25 x 10^-17 erg s^-1 cm^-2 on average. For DLAs without this feature in their troughs, the average 3-\\sigma\\ upper limit is 75%) of these DLAs, with only a minority (< 25%) arising from HI clouds located in the AGN host galaxy.

Finley, Hayley; Pâris, Isabelle; Noterdaeme, Pasquier; Brinkmann, Jonathan; Myers, Adam D; Ross, Nicholas P; Schneider, Donald P; Bizyaev, Dmitry; Brewington, Howard; Ebelke, Garrett; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie

2013-01-01T23:59:59.000Z

238

Reconstructing the Cosmic Expansion History up to Redshift z=6.29 with the Calibrated Gamma-Ray Bursts  

E-Print Network (OSTI)

Recently, Gamma-Ray Bursts (GRBs) were proposed to be a complementary cosmological probe to type Ia supernovae (SNIa). GRBs have been advocated to be standard candles since several empirical GRB luminosity relations were proposed as distance indicators. However, there is a so-called circularity problem in the direct use of GRBs. Recently, a new idea to calibrate GRBs in a completely cosmology independent manner has been proposed, and the circularity problem can be solved. In the present work, following the method proposed by Liang {\\it et al.}, we calibrate 70 GRBs with the Amati relation using 307 SNIa. Then, following the method proposed by Shafieloo {\\it et al.}, we smoothly reconstruct the cosmic expansion history up to redshift $z=6.29$ with the calibrated GRBs. We find some new features in the reconstructed results.

Hao Wei; Shuang Nan Zhang

2008-08-18T23:59:59.000Z

239

Section D: SPACE HEATING  

U.S. Energy Information Administration (EIA)

2005 Residential Energy Consumption Survey Form EIA-457A (2005)--Household Questionnaire OMB No.: 1905-0092, Expiring May 31, 2008 33 Section D: SPACE HEATING

240

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings*...

242

Passive solar space heating  

DOE Green Energy (OSTI)

An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

Balcomb, J.D.

1980-01-01T23:59:59.000Z

243

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings*...

244

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

245

On Multi-Metric Spaces  

E-Print Network (OSTI)

A Smarandache multi-space is a union of $n$ spaces $A_1,A_2,..., A_n$ with some additional conditions holding. Combining Smarandache multi-spaces with classical metric spaces, the conception of multi-metric space is introduced. Some characteristics of a multi-metric space are obtained and Banach's fixed-point theorem is generalized in this paper.

Linfan Mao

2005-10-22T23:59:59.000Z

246

Space bounds for resolution  

Science Conference Proceedings (OSTI)

We introduce a new way to measure the space needed in a resolution refutation of a CNF formula in propositional logic. With the former definition [6] the space required for the resolution of any unsatisfiable formula in CNF is linear in the number of ...

Juan Luis Esteban; Jacobo Torán

1999-03-01T23:59:59.000Z

247

The metaplastic virtual spaces  

Science Conference Proceedings (OSTI)

Virtual reality systems need new metaphors for their communication. This paper presents a fuzzy enhanced semantic virtual space model. The application of the model tries to improve its conceptualization and definition of a new virtual world system. The ... Keywords: fuzzy, metaphysical, semantic spaces, synaesthesia, virtual reality

Gianluca Mura

2007-09-01T23:59:59.000Z

248

Atoms for space  

SciTech Connect

Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

Buden, D.

1990-10-01T23:59:59.000Z

249

Reynolds and Favre-averaged rapid distortion theory for compressible, ideal-gas turbulence  

E-Print Network (OSTI)

Compressible ideal-gas turbulence subjected to homogeneous shear is investigated at the rapid distortion limit. Specific issues addressed are (i) the interaction between kinetic and internal energies and role of pressure-dilatation; (ii) the modifications to pressure-strain correlation and Reynolds stress anisotropy and (iii) the effect of the composition of velocity fluctuations (solenoidal vs. dilatational). Turbulence evolution is found to be strongly influenced by gradient Mach number, the initial solenoidal-to-dilatational ratio of the velocity field and the initial intensity of the thermodynamic fluctuations. The balance between the initial fluctuations in velocity and thermodynamic variables is also found to be very important. Any imbalance in the two fluctuating fields leads to high levels of pressure-dilatation and intense exchange. For a given initial condition, it is found that the interaction via the pressuredilatation term between the momentum and energy equations reaches a peak at an intermediate gradient Mach number. The energy exchange between internal and kinetic modes is negligible at very high or very low Mach number values due to lack of pressure dilatation. When present, the exchange exhibits oscillations even as the sum of the two energies evolves smoothly. The interaction between shear and solenoidal initial velocity field generates dilatational fluctuations; for some intermediate levels of shear Mach number dilatational fluctuations account for 20% of the total fluctuations. Similarly, the interaction between shear and initial dilatation produces solenoidal oscillations. Somewhat surprisingly, the generation of solenoidal fluctuations increases with gradient Mach number. Larger levels of pressure-strain correlation are seen with dilatational rather than solenoidal initial conditions. Anisotropies of solenoidal and dilatational components are investigated individually. The most interesting observation is that solenoidal and dilatational turbulence tend toward a one componential state but the energetic component is different in each case. As in incompressible shear flows, with solenoidal fluctuations, the streamwise (1,1) component of Reynolds stress is dominant. With dilatational fluctuations, the stream-normal (2,2) component is the strongest. Overall, the study yields valuable insight into the linear processes in high Mach number shear flows and identifies important closure modeling issues.

Lavin, Tucker Alan

2003-05-01T23:59:59.000Z

250

Tangent spaces to metric spaces and to their subspaces  

E-Print Network (OSTI)

We investigate a tangent space at a point of a general metric space and metric space valued derivatives. The conditions under which two different subspace of a metric space have isometric tangent spaces in a common point of these subspaces are completely determinated.

Dovgoshey, O

2009-01-01T23:59:59.000Z

251

National Aeronautics and Space Administration Space Shuttle Era Facts  

E-Print Network (OSTI)

System (STS), began its flight career with Columbia roaring off Launch Pad 39A at NASA's Kennedy SpaceNational Aeronautics and Space Administration NASAfacts Space Shuttle Era Facts NASA's shuttle fleet achieved numerous firsts and opened up space to more people than ever before during the Space

252

Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices  

E-Print Network (OSTI)

This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...

Fallier, William F. (William Frederick)

2007-01-01T23:59:59.000Z

253

On globally Symmetric Finsler spaces  

E-Print Network (OSTI)

The paper consider the symmetric of Finsler spaces. We give some conditions about globally symmetric Finsler spaces. Then we prove that these spaces can be written as a coset space of Lie group with an invariant Finsler metric. Finally, we prove that such a space must be Berwaldian

Khatamy, R Chavosh

2011-01-01T23:59:59.000Z

254

Simplified Space Conditioning  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Simplified Space Conditioning Simplified Space Conditioning Duncan Prahl, RA IBACOS, Inc. Building America Technical Update April 29, 2013 Simplified Space Conditioning Rethinking HVAC Design * Traditional Method - Assume envelope losses dictate the load - Room by room load analysis - Pick Equipment and distribute to meet the load in each room * New Method - Consider how the occupants live in the building - Seriously consider internal gains in both heating and cooling - Consider ventilation strategy - Design system Simplified Space Conditioning If you are: * A production builder * Participating in "above code" programs * Following ACCA Manual RS or ASHRAE 55 * Need to prove "delivering heat to each habitable room" * Concerned about litigation * Play it safe, Use Manual J, S & D and condition every

255

Live From Outer Space  

NLE Websites -- All DOE Office Websites (Extended Search)

Live from Outer Space: How Cells Influence the Growth of Nanostructures Live from Outer Space: How Cells Influence the Growth of Nanostructures Far above the heads of Earthlings, arrays of single-cell creatures embedded in nanostructures ride on the International Space Station (courtesy of Sandia National Laboratories and the University of New Mexico, NASA, and the U.S. Air Force) to test whether nanostructures whose formations were directed by yeast and other single cells can create more secure homes for their occupants-even in the vacuum and radiation of outer space-than those created by more standard chemical procedures. Cheap, tiny, and very lightweight sensors of chemical or biological agents could be made from long-lived cells that require no upkeep, yet sense and then communicate effectively with each other and their external

256

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other...

257

Space Mapping - Optimization Online  

E-Print Network (OSTI)

Thus, we can usec oP–to locally minimize the surrogatecoP that the space. mappingP provides for the fine model“.An alternative surrogate introduced byMadsen ...

258

A UNIVERSAL, LOCAL STAR FORMATION LAW IN GALACTIC CLOUDS, NEARBY GALAXIES, HIGH-REDSHIFT DISKS, AND STARBURSTS  

SciTech Connect

Star formation laws are rules that relate the rate of star formation in a particular region, either an entire galaxy or some portion of it, to the properties of the gas, or other galactic properties, in that region. While observations of Local Group galaxies show a very simple, local star formation law in which the star formation rate per unit area in each patch of a galaxy scales linearly with the molecular gas surface density in that patch, recent observations of both Milky Way molecular clouds and high-redshift galaxies apparently show a more complicated relationship in which regions of equal molecular gas surface density can form stars at quite different rates. These data have been interpreted as implying either that different star formation laws may apply in different circumstances, that the star formation law is sensitive to large-scale galaxy properties rather than local properties, or that there are high-density thresholds for star formation. Here we collate observations of the relationship between gas and star formation rate from resolved observations of Milky Way molecular clouds, from kpc-scale observations of Local Group galaxies, and from unresolved observations of both disk and starburst galaxies in the local universe and at high redshift. We show that all of these data are in fact consistent with a simple, local, volumetric star formation law. The apparent variations stem from the fact that the observed objects have a wide variety of three-dimensional size scales and degrees of internal clumping, so even at fixed gas column density the regions being observed can have wildly varying volume densities. We provide a simple theoretical framework to remove this projection effect, and we use it to show that all the data, from small solar neighborhood clouds with masses {approx}10{sup 3} M{sub Sun} to submillimeter galaxies with masses {approx}10{sup 11} M{sub Sun }, fall on a single star formation law in which the star formation rate is simply {approx}1% of the molecular gas mass per local free-fall time. In contrast, proposed star formation laws in which the star formation timescale is set by the galactic rotation period are inconsistent with the data from the Milky Way and the Local Group, while those in which the star formation rate is linearly proportional to the gas mass above some density threshold fail both in the Local Group and for starburst galaxies.

Krumholz, Mark R. [Department of Astronomy, University of California, Santa Cruz, CA 95064 (United States); Dekel, Avishai [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); McKee, Christopher F., E-mail: krumholz@ucolick.org, E-mail: dekel@phys.huji.ac.il, E-mail: cmckee@astro.berkeley.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)

2012-01-20T23:59:59.000Z

259

Beam Space Propulsion  

E-Print Network (OSTI)

Author offers a revolutionary method non-rocket transfer of energy and thrust into Space with distance of millions kilometers. The author has developed theory and made the computations. The method is more efficient than transmission of energy by high-frequency waves. The method may be used for space launch and for acceleration the spaceship and probes for very high speeds, up to relativistic speed by current technology. Research also contains prospective projects which illustrate the possibilities of the suggested method.

Alexander Bolonkin

2007-01-04T23:59:59.000Z

260

Space Weather 101  

Science Conference Proceedings (OSTI)

This report describes the basic physical concepts associated with space weather that pertain to the effects on high-voltage power transmission systems. Space weather is an extremely complex and multi-faceted phenomenon. To focus on power grid–related effects, the report addresses coronal mass ejections, which are known to be the most important driver of large geomagnetically induced currents, and describes ongoing research that is being conducted to better understand, predict, and mitigate the ...

2012-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

A MULTI-WAVELENGTH STUDY OF LOW-REDSHIFT CLUSTERS OF GALAXIES. II. ENVIRONMENTAL IMPACT ON GALAXY GROWTH  

Science Conference Proceedings (OSTI)

Galaxy clusters provide powerful laboratories for the study of galaxy evolution, particularly the origin of correlations of morphology and star formation rate (SFR) with density. We construct visible to MIR spectral energy distributions of galaxies in eight low-redshift (z 99% confidence) with no dependence on R/R{sub 200} or projected local density at fixed mass. A merged sample of galaxies from the five best measured clusters shows (SFR){proportional_to}(R/R{sub 200}){sup 1.1{+-}0.3} for galaxies with R/R{sub 200} {R {R{sub 200}. The increase in the fraction of SFGs toward larger R/R{sub 200} and the isolation of SFGs with reduced SFRs near the cluster center are consistent with the truncation of star formation by ram-pressure stripping, as is the tendency for more massive SFGs to have higher SFRs. We conclude that stripping is more likely than slower processes to drive the properties of SFGs with R R{sub 200} in clusters. We also find that galaxies near the cluster center are more massive than galaxies farther out in the cluster at {approx}3.5{sigma}, which suggests that dynamical relaxation significantly impacts the distribution of cluster galaxies as the clusters evolve.

Atlee, David W.; Martini, Paul, E-mail: atlee@noao.edu [Department of Astronomy, Ohio State University, 4055 McPherson Laboratory, 140 W. 18th Ave., Columbus, OH 43210 (United States)

2012-12-20T23:59:59.000Z

262

Parabolic John-Nirenberg spaces  

E-Print Network (OSTI)

We introduce a parabolic version of John-Nirenberg space with exponent $p$ and show that it is contained in local weak-$L^p$ spaces.

Berkovits, Lauri

2011-01-01T23:59:59.000Z

263

Analytic fit of deviation caused by atmospheric refraction of starlight as a function of space-based sensor position  

Science Conference Proceedings (OSTI)

A simple prescription describes how space-borne sensors with fields of view less than one degree can be properly aimed at starlight that passes near the Earth`s surface and is therefore refracted by the Earth`s atmosphere. Atmospheric refraction effects cause deviations up to about one degree that distort the light path and can cause the target to be missed. Deviations are contrasted with those experienced for a target on the Earth. Such refractive corrections have long been available for Earth-based sensors looking through the atmosphere. The corrections have not been available for sensors in space. The prescription is illustrated by example.

Vittitoe, C.N.; Schmidt, R.L. [Sandia National Labs., Albuquerque, NM (United States). Optics and Exploratory Technologies Dept.

1997-06-01T23:59:59.000Z

264

THE RISE AND FALL OF THE STAR FORMATION HISTORIES OF BLUE GALAXIES AT REDSHIFTS 0.2 < z < 1.4  

Science Conference Proceedings (OSTI)

Popular cosmological scenarios predict that galaxies form hierarchically from the merger of many progenitors, each with their own unique star formation history (SFH). We use a sophisticated approach to constrain the SFHs of 4517 blue (presumably star-forming) galaxies with spectroscopic redshifts in the range 0.2 < z < 1.4 from the All-Wavelength Extended Groth Strip International Survey. This consists in the Bayesian analysis of the observed galaxy spectral energy distributions with a comprehensive library of synthetic spectra assembled using realistic, hierarchical star formation, and chemical enrichment histories from cosmological simulations. We constrain the SFH of each galaxy in our sample by comparing the observed fluxes in the B, R, I, and K{sub s} bands and rest-frame optical emission-line luminosities with those of one million model spectral energy distributions. We explore the dependence of the resulting SFHs on galaxy stellar mass and redshift. We find that the average SFHs of high-mass galaxies rise and fall in a roughly symmetric bell-shaped manner, while those of low-mass galaxies rise progressively in time, consistent with the typically stronger activity of star formation in low-mass compared to high-mass galaxies. For galaxies of all masses, the star formation activity rises more rapidly at high than at low redshift. These findings imply that the standard approximation of exponentially declining SFHs widely used to interpret observed galaxy spectral energy distributions may not be appropriate to constrain the physical parameters of star-forming galaxies at intermediate redshifts.

Pacifici, Camilla [Yonsei University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of); Kassin, Susan A.; Gardner, Jonathan P. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Weiner, Benjamin [Steward Observatory, 933 North Cherry Street, University of Arizona, Tucson, AZ 85721 (United States); Charlot, Stephane [UPMC-CNRS, UMR7095, Institut d'Astrophysique de Paris, F-75014 Paris (France)

2013-01-01T23:59:59.000Z

265

Earth, Space Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Earth, Space Sciences Earth, Space Sciences /science-innovation/_assets/images/icon-science.jpg Earth, Space Sciences National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. Climate, Ocean and Sea Ice Modeling (COSIM)» Earth A team of scientists is working to understand how local changes in hydrology might bring about major changes to the Arctic landscape, including the possibility of a large-scale carbon release from thawing permafrost. Bryan Travis, an expert in fluid dynamics, is author of the Mars global hydrology numerical computer model, or MAGHNUM, used for calculating heat and fluid transport phenomena. (MAGHNUM was previously

266

International Space Station Again  

E-Print Network (OSTI)

For the fifth time in 2 1/2 years, the International Space Station (ISS) had to execute a collision avoidance maneuver in early April to ensure a safe miss distance for a piece of orbital debris. As solar activity increases during the next few years, the frequency of ISS collision avoidance might increase as many hundreds of resident space objects drift down through the ISS orbital regime. The subject of concern in late March 2011 was a fragment from Cosmos 2251, the Russian communications satellite which had accidentally collided with the U.S. Iridium 33 communications satellite in February 2009, producing more than

Iss Airlock Shields; A Note On Active; A Publication Of

2011-01-01T23:59:59.000Z

267

 

NLE Websites -- All DOE Office Websites (Extended Search)

Galaxy Redshifts and Peculiar Velocities - Current Mysteries Galaxy Redshifts and Peculiar Velocities - Current Mysteries and Future Prospects Edward Macaulay (Oxford) Abstract: Galaxy redshift and peculiar velocity surveys provide a wealth of insight on cosmology, dark matter, and dark energy. Peculiar velocities can be measured at z=0 with hundreds of luminosity distances, or inferred at z>0 with Redshift Space Distortions (RSDs) from thousands of redshifts. In this talk, I'll present results with both methods which can appear in tension with Lambda-CDM. Many recent RSD measurements are systematically lower than LCDM, hinting that w>-1 (although with a surprisingly low scatter in the data). At z=0, the velocity dipole is several times higher than LCDM. I'll show results from the COMPOSITE peculiar velocity catalogue - the largest

268

Demystifying White Spaces Xuemin Hongl  

E-Print Network (OSTI)

white spaces. The term "white space" refers to "spatial white space" in the rest of this paper cellular (planned) networks [9] and ad-hoc networks [10]. Different from previous works, in this paper weDemystifying White Spaces Xuemin Hongl , Cheng-Xiang Wangl , John Thompson2 , and Yan Zhang3 1Joint

Wang, Cheng-Xiang

269

A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY  

SciTech Connect

We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ (United States); Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A. [Space Telescope Science Institute, Baltimore, MD (United States); Spinrad, Hyron [University of California, Berkeley, CA (United States); Reddy, Naveen [University of California, Riverside, CA (United States); Hathi, Nimish [Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States); Budavari, Tamas [Johns Hopkins University, Baltimore, MD (United States); Ferreras, Ignacio [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Gardner, Jonathan P. [NASA Goddard Space Flight Center, Astrophysics Science Division, Observational Cosmology Laboratory, Code 665, Greenbelt, MD 20771 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); Haiman, Zoltan [Columbia University, New York, NY (United States); Kuemmel, Martin [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Meurer, Gerhardt, E-mail: James.Rhoads@asu.edu [International Centre for Radio Astronomy Research, University of Western Australia, M468, 35 Stirling Highway, Crawley, WA 6009 (Australia); and others

2013-08-10T23:59:59.000Z

270

FORECASTING COSMOLOGICAL PARAMETER CONSTRAINTS FROM NEAR-FUTURE SPACE-BASED GALAXY SURVEYS  

Science Conference Proceedings (OSTI)

The next generation of space-based galaxy surveys is expected to measure the growth rate of structure to a level of about one percent over a range of redshifts. The rate of growth of structure as a function of redshift depends on the behavior of dark energy and so can be used to constrain parameters of dark energy models. In this work, we investigate how well these future data will be able to constrain the time dependence of the dark energy density. We consider parameterizations of the dark energy equation of state, such as XCDM and {omega}CDM, as well as a consistent physical model of time-evolving scalar field dark energy, {phi}CDM. We show that if the standard, specially flat cosmological model is taken as a fiducial model of the universe, these near-future measurements of structure growth will be able to constrain the time dependence of scalar field dark energy density to a precision of about 10%, which is almost an order of magnitude better than what can be achieved from a compilation of currently available data sets.

Pavlov, Anatoly; Ratra, Bharat [Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, KS 66506 (United States); Samushia, Lado, E-mail: pavlov@phys.ksu.edu, E-mail: ratra@phys.ksu.edu, E-mail: lado.samushia@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX (United Kingdom)

2012-11-20T23:59:59.000Z

271

Programs on Product Spaces  

Science Conference Proceedings (OSTI)

We study program states that are described as tuples, i.e., product state spaces. We show how to add program variables and assignment notation to simply typed lambda calculus in order to describe functions, relations and predicate transformers on such ...

Ralph Back; Joakim Wright von

1997-12-01T23:59:59.000Z

272

Capacity on Finsler Spaces  

E-Print Network (OSTI)

Here, the concept of electric capacity on Finsler spaces is introduced and the fundamental conformal invariant property is proved, i.e. the capacity of a compact set on a connected non-compact Finsler manifold is conformal invariant. This work enables mathematicians and theoretical physicists to become more familiar with the global Finsler geometry and one of its new applications.

Bidabad, B

2009-01-01T23:59:59.000Z

273

2011 Confined Space Program Update  

NLE Websites -- All DOE Office Websites (Extended Search)

Confined Space Entry Program Update Confined Space Entry Program Update IMPORTANT: After reading this document, click the "Get Course Credit" link at the bottom of the page. You will then log in to the EHS training system using your LDAP to get course credit. LBNL's confined space entry program was substantially improved this year. Several new features have been included which improve overall safety for Confined Space Entrants and better align the confined space entry program with the OSHA requirements. As an Activity Lead, Confined Space Entrant or Entry Supervisor, you should be aware of the following: We improved the procedures for safely working in confined spaces. Please review the new Chapter 34 in Publication 3000. Additionally, we have a new planning tool known as the confined space inventory which is a registry of LBNL's confined spaces, their potential hazards and safe work procedures unique to a particular confined space.

274

Redshifted emission lines and radiative recombination continuum from the Wolf-Rayet binary theta Muscae: evidence for a triplet system?  

E-Print Network (OSTI)

We present XMM-Newton observations of the WC binary Theta Muscae (WR 48), the second brightest Wolf-Rayet binary in optical wavelengths. The system consists of a short-period (19.1375 days) WC5/WC6 + O6/O7V binary and possibly has an additional O supergiant companion (O9.5/B0Iab) which is optically identified at a separation of ~46 mas. Strong emission lines from highly ionized ions of C, O, Ne, Mg, Si, S, Ar, Ca and Fe are detected. The spectra are fitted by a multi-temperature thin-thermal plasma model with an interstellar absorption N_H = 2--3*10**21 cm**-2. Lack of nitrogen line indicates that the abundance of carbon is at least an order of magnitude larger than that of nitrogen. A Doppler shift of ~630 km/s is detected for the OVIII line, while similar shifts are obtained from the other lines. The reddening strongly suggests that the emission lines originated from the wind-wind shock zone, where the average velocity is ~600 km/s. The red-shift motion is inconsistent with a scenario in which the X-rays originate from the wind-wind collision zone in the short-period binary, and would be evidence supporting the widely separated O supergiant as a companion. This may make up the collision zone be lying behind the short-period binary. In addition to the emission lines, we also detected the RRC (radiative recombination continuum) structure from carbon around 0.49 keV. This implies the existence of additional cooler plasma.

Yasuharu Sugawara; Yohko Tsuboi; Yoshitomo Maeda

2008-10-07T23:59:59.000Z

275

Mapping the Dark Matter From UV Light at High Redshift: An Empirical Approach to Understand Galaxy Statistics  

SciTech Connect

We present a simple formalism to interpret the observations of two galaxy statistics, the UV luminosity function (LF) and two-point correlation functions for star-forming galaxies at z {approx} 4, 5 and 6 in the context of {Lambda}CDM cosmology. Both statistics are the result of how star formation takes place in dark matter halos, and thus are used to constrain how UV light depends on halo properties, in particular halo mass. The two physical quantities we explore are the star formation duty cycle, and the range of UV luminosity that a halo of mass M can have (mean and variance). The former directly addresses the typical duration of star formation activity in halos while the latter addresses the averaged star formation history and regularity of gas inflow into these systems. In the context of this formalism, we explore various physical models consistent with all the available observational data, and find the following: (1) the typical duration of star formation observed in the data is {approx}< 0.4 Gyr (1{sigma}), (2) the inferred scaling law between the observed L{sub UV} and halo mass M from the observed faint-end slope of the luminosity functions is roughly linear out to M {approx} 10{sup 11.5} - 10{sup 12} h{sup -1} M{sub {circle_dot}} at all redshifts probed in this work, and (3) the observed L{sub UV} for a fixed halo mass M decreases with time, implying that the star formation efficiency (after dust extinction) is higher at earlier times. We explore several different physical scenarios relating star formation to halo mass, but find that these scenarios are indistinguishable due to the limited range of halo mass probed by our data. In order to discriminate between different scenarios, we discuss the possibility of using the bright-faint galaxy cross-correlation functions and more robust determination of luminosity-dependent galaxy bias for future surveys.

Lee, Kyoung-Soo; /Yale Ctr. Astron. Astrophys.; Giavalisco, Mauro; /Massachusetts U., Amherst; Conroy, Charlie; /Princeton U. Observ.; Wechsler, Risa H; /KIPAC, Menlo Park; Ferguson, Henry C.; Somerville, Rachel S.; /Baltimore, Space Telescope Sci.; Dickinson, Mark E.; /NOAO, Tucson; Urry, Claudia M.; /Yale Ctr. Astron. Astrophys.

2009-08-03T23:59:59.000Z

276

Stability of Jahn-Teller distortion in LaMnO{sub 3} under pressure: An x-ray absorption study  

SciTech Connect

The local environment of manganese atoms in LaMnO{sub 3} under pressure up to 15.3 GPa has been studied by x-ray absorption spectroscopy. For pressures below 8 GPa, no change is detected within the MnO{sub 6} octahedra. Above this pressure a continuous reduction of the long Mn-O distance takes place, however, the octahedral distortion persists over the whole pressure range. At 15.3 GPa the average Jahn-Teller splitting of the distances is reduced by about one-third, indicating that a total removal of the local Jahn-Teller distortion would occur only for pressures around 30 GPa, where metallization is reported to take place. A hysteresis in the long distance reduction is observed down to ambient pressure, suggesting the coexistence of MnO{sub 6} distorted and undistorted units.

Ramos, Aline Y.; Tolentino, Helio C. N.; Souza-Neto, Narcizo M.; Itie, Jean-Paul; Morales, Liliana; Caneiro, Alberto [Institut Neel, UPR 2940-CNRS, 25 av. des Martyrs, Boite Postale 166, 38042 Grenoble, France and Laboratorio Nacional de Luz Sincrotron-LNLS, P.O. Box 6192, 13084-971, Campinas, Sao Paulo (Brazil); Laboratorio Nacional de Luz Sincrotron-LNLS, P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and Departamento de Fisica dos Materiais e Mecanica, DFMT-IF-USP, Sao Paulo, SP (Brazil); Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, Boite Postale 48, 91192 Gif-sur-Yvette Cedex (France); Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica and Universidad Nacional de Cuyo, 8400 S.C. de Bariloche (Argentina)

2007-02-01T23:59:59.000Z

277

Observation of Orbital Ordering and Jahn-Teller Distortions Supporting the Wigner-crystal Model in Highly Dopes Bi{1-x}Ca{x}MnO{3}  

SciTech Connect

We report on the experimental characterization of orbital ordering and the associated lattice distortions in highly doped Bi{sub 1-x}Ca{sub x}MnO{sub 3}. Resonant x-ray diffraction was used at the Mn L-edge for the direct observation of the ordered localized states, and at the Mn K-edge for the sensitivity to the distortions of the manganese-oxygen octahedra. The orbital ordering on Mn atoms was directly observed at x=0.69; the analysis and the numerical simulations of the K-edge spectra allow us to characterize the pattern of the distorted octahedra at x = 4/5. These observations support the Wigner-crystal-type model at both dopings; the bi-stripe model is ruled out at x = 0.69.

Grenier,S.; Kiryukhin, V.; Cheong, S.; Kim, B.; Hill, J.; Thomas, K.; Tonnerre, J.; Joly, Y.; Staub, U.; Scagnoli, V.

2007-01-01T23:59:59.000Z

278

Magnetic Space Launcher  

E-Print Network (OSTI)

A method and facilities for delivering payload and people into outer space are presented. This method uses, in general, engines located on a planetary surface. The installation consists of a space apparatus, power drive stations, which include a flywheel accumulator (for storage) of energy, a variable reducer, a powerful homopolar electric generator and electric rails. The drive stations accelerate the apparatus up to hypersonic speed. The estimations and computations show the possibility of making this project a reality in a short period of time (for payloads which can tolerate high g-forces). The launch will be very cheap at a projected cost of 3 - 5 dollars per pound. The authors developed a theory of this type of the launcher.

Alexander Bolonkin; Mark Krinker

2009-03-28T23:59:59.000Z

279

MHD Space Sailing  

E-Print Network (OSTI)

The rocket technology dates back as far as medieval China. Used initially for entertainment and religious practices over time rockets evolved into weapons and finally into means of transportation. Today, we are nearing the top of the rockets' capabilities. Although, for now they are the only way for us to send anything into space we are becoming more and more aware of the limitations of this technology. It is essential that we invent other means of propelling probes and other interplanetary vehicles through space. The authors had performed a series of magnetohydrodynamic simulations using the University of Chicago's Flash package to find out whether the interactions between the Solar Wind and the conducting ring with the electric current would occur. The MHD simulations gave the results similar to the monte-carlo calculations performed by dr Charles Danforth [1] from the University of Colorado. It is the authors' conclusion that the promising results should encourage further study of the phenomenon and the po...

Kisiel, T

2007-01-01T23:59:59.000Z

280

Orbit Spaces in Superconductivity  

E-Print Network (OSTI)

In the framework of Landau theory of phase transitions one is interested to describe all the possible low symmetry ``superconducting'' phases allowed for a given superconductor crystal and to determine the conditions under which this crystal undergoes a phase transition. These problems are best described and analyzed in the orbit space of the high symmetry group of the ``normal, non-superconducting'' phase of the crystal. In this article it is worked out a simple example concerning superconductivity, that shows the P-matrix method to determine the equations and inequalities defining the orbit space and its stratification. This approach is of general validity and can be used in all physical problems that make use of invariant functions, as long as the symmetry group is compact.

Vittorino Talamini

2006-07-30T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Dendrite Arm Spacing  

Science Conference Proceedings (OSTI)

...Casting processes Cooling rate Dendrite arm spacing °C/s °F/s μm mils Plaster, investment 1 1.80 100â??1000 3.94â??39.4 Green sand, shell 10 18.0 50â??500 1.97â??19.7 Permanent mold 100 180.0 30â??70 1.18â??2.76 Die 1000 1800 5â??15 0.20â??0.59...

282

Space Time Matter inflation  

E-Print Network (OSTI)

We study a model of power-law inflationary inflation using the Space-Time-Matter (STM) theory of gravity for a five dimensional (5D) canonical metric that describes an apparent vacuum. In this approach the expansion is governed by a single scalar (neutral) quantum field. In particular, we study the case where the power of expansion of the universe is $p \\gg 1$. This kind of model is more successful than others in accounting for galaxy formation.

Mariano Anabitarte; Mauricio Bellini

2005-08-31T23:59:59.000Z

283

Nowcasting for Space Shuttle Landings at Kennedy Space Center, Florida  

Science Conference Proceedings (OSTI)

Space shuttle launches and landings at Kennedy Space Center (KSC) are subject to strict weather-related launch commit criteria and landing weather flight rules. Complex launch commit criteria and end-of-mission landing weather flight rules demand ...

William H. Bauman III; Steven Businger

1996-10-01T23:59:59.000Z

284

Lens space surgeries and L-space homology spheres  

E-Print Network (OSTI)

We describe necessary and sufficient conditions for a knot in an L-space to have an L-space homology sphere surgery. We use these conditions to reformulate a conjecture of Berge about which knots in S^3 admit lens space surgeries.

Rasmussen, Jacob

2007-01-01T23:59:59.000Z

285

Symplectic space and orthogonal space of n qubits  

E-Print Network (OSTI)

In the Hilbert space of n qubits, we introduce the symplectic space (n odd) and the orthogonal space (n even) via the spin-flip operator. Under this mathematical structure we discuss some properties of n qubits, including homomorphically mapping the local operations of n qubits into the symplectic group or orthogonal group, and prove that the generalized ``magic basis'' is just the bi-orthonormal basis (that is, the orthonormal basis of both Hilbert space and the orthogonal space ). Finally, an example is given to discuss the application in physics of this mathematical structure.

Jian-Wei Xu

2010-11-14T23:59:59.000Z

286

Particle simulations of space weather  

Science Conference Proceedings (OSTI)

We review the application of particle simulation techniques to the full kinetic study of space weather events. We focus especially on the methods designed to overcome the difficulties created by the tremendous range of time and space scales present in ... Keywords: Adaptive, Implicit, Particle-in-cell, Space weather

Giovanni Lapenta

2012-02-01T23:59:59.000Z

287

Upgrading Below Grade Spaces  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Patrick H. Huelman, Sam Breidenbach, Steve Schirber Patrick H. Huelman, Sam Breidenbach, Steve Schirber NorthernSTAR Building America Partnership Upgrading Below Grade Spaces Residential Energy Efficiency Stakeholder March 1, 2012 Austin, TX * Act 1: Technical Challenges & Opportunities - Pat Huelman, University of Minnesota * Act 2: Assessing Homeowner Priorities & Risks - Sam Breidenbach, TDS Custom Construction * Act 3: An Industry Perspective - Steve Schirber, Cocoon Act 1. Upgrade Below Grade * Basement Remodeling: It Doesn't Get Any Riskier! - Combustion safety - Foundation moisture - Radon (& other soil gases) - Biologicals (mold, dust mites, etc.) - Garage gases (if attached) * And front and center are uncontrolled... - negative pressures in basements (beyond stack)

288

space booklet_DOE  

NLE Websites -- All DOE Office Websites (Extended Search)

U U C L E A R E N E R G Y DOE/NE-0071 U . S . D e p a r t m e n t o f E n e r g y O f f i c e o f N u c l e a r E n e r g y , S c i e n c e a n d T e c h n o l o g y N UCLEAR Power in Space 2

289

MHD Space Sailing  

E-Print Network (OSTI)

The rocket technology dates back as far as medieval China. Used initially for entertainment and religious practices over time rockets evolved into weapons and finally into means of transportation. Today, we are nearing the top of the rockets' capabilities. Although, for now they are the only way for us to send anything into space we are becoming more and more aware of the limitations of this technology. It is essential that we invent other means of propelling probes and other interplanetary vehicles through space. The authors had performed a series of magnetohydrodynamic simulations using the University of Chicago's Flash package to find out whether the interactions between the Solar Wind and the conducting ring with the electric current would occur. The MHD simulations gave the results similar to the monte-carlo calculations performed by dr Charles Danforth [1] from the University of Colorado. It is the authors' conclusion that the promising results should encourage further study of the phenomenon and the possibility of using it in practice.

T. Kisiel; M. Soida

2007-12-10T23:59:59.000Z

290

Intelligent Satellite Teams Space Systems  

E-Print Network (OSTI)

This paper examines the development of Intelligent Satellite Teams (IST's) for complex space missions such as construction of space hardware, or Earth or space science. IST's are composed of many nanosatellites (mass control including formation flying, collision avoidance, knowledge sharing, and adaptive reconfiguration; microtechnology including microelectromechanical systems (MEMS), microfabricated sensors and actuators, nanotechnology, and integrated wireless communication; mission analysis -- high-level planning and control of mission, satellites, and procedures. Recent rapid technological advances in these fields open up exciting new possibilities for future space missions: space science missions such as testing gravitational variation, detecting and characterizing near-Earth asteroids and comets, and comprehensive exploration of the solar system; Earth science missions ...

Mark E. Campbell; Karl F. Böhringer

1999-01-01T23:59:59.000Z

291

A Measurement of the Rate of type-Ia Supernovae at Redshift $z\\approx$ 0.1 from the First Season of the SDSS-II Supernova Survey  

E-Print Network (OSTI)

We present a measurement of the rate of type Ia supernovae (SNe Ia) from the first of three seasons of data from the SDSS-II Supernova Survey. For this measurement, we include 17 SNe Ia at redshift $z\\le0.12$. Assuming a flat cosmology with $\\Omega_m = 0.3=1-\\Omega_\\Lambda$, we find a volumetric SN Ia rate of $[2.93^{+0.17}_{-0.04}({\\rm systematic})^{+0.90}_{-0.71}({\\rm statistical})] \\times 10^{-5} {\\rm SNe} {\\rm Mpc}^{-3} h_{70}^3 {\\rm year}^{-1}$, at a volume-weighted mean redshift of 0.09. This result is consistent with previous measurements of the SN Ia rate in a similar redshift range. The systematic errors are well controlled, resulting in the most precise measurement of the SN Ia rate in this redshift range. We use a maximum likelihood method to fit SN rate models to the SDSS-II Supernova Survey data in combination with other rate measurements, thereby constraining models for the redshift-evolution of the SN Ia rate. Fitting the combined data to a simple power-law evolution of the volumetric SN Ia rat...

Dilday, Benjamin; Frieman, J A; Holtzman, J; Marriner, J; Miknaitis, G; Nichol, R C; Romani, R; Sako, M; Bassett, B; Becker, A; Cinabro, D; De Jongh, F; Depoy, D L; Doi, M; Garnavich, P M; Hogan, C J; Jha, S; Konishi, K; Lampeitl, H; Marshall, J L; McGinnis, D; Prieto, J L; Riess, A G; Richmond, M W; Schneider, D P; Smith, M; Takanashi, N; Tokita, K; van der Heyden, K; Zheng, N Yasuda C; Barentine, J; Brewington, H; Choi, C; Crotts, A; Dembicky, J; Harvanek, M; Im, M; Ketzeback, W; Kleinman, S J; KrzesiÅ?ski, J; Long, D C; Malanushenko, E; Malanushenko, V; McMillan, R J; Nitta, A; Pan, K; Saurage, G; Snedden, S A; Watters, S; Wheeler, J C; York, D

2008-01-01T23:59:59.000Z

292

Keck Deep Fields. I. Observations, Reductions, and the Selection of Faint Star-Forming Galaxies at Redshifts z~4, 3, and 2  

E-Print Network (OSTI)

We introduce a very deep, R_lim~27, multicolor imaging survey of very faint star-forming galaxies at z~4, z~3, z~2.2, and z~1.7. This survey, carried out on the Keck I telescope, uses the very same UGRI filter system that is employed by the Steidel team to select galaxies at these redshifts, and thus allows us to construct identically-selected, but much fainter, samples. However, our survey reaches ~1.5 mag deeper than the work of Steidel and his group, letting us probe substantially below the characteristic luminosity L* and thus study the properties and redshift evolution of the faint component of the high-z galaxy population. The survey covers 169 square arcminutes in three spatially independent patches on the sky and -- to R<~27 -- contains 427 GRI-selected z~4 LBGs, 1481 UGR-selected z~3 LBGs, 2417 UGR-selected z~2.2 star-forming galaxies, and 2043 UGR-selected z~1.7 star-forming galaxies. In this paper, the first in a series, we introduce the survey, describe our observing and data reduction strategies, and outline the selection of our z~4, z~3, z~2.2, and z~1.7 samples.

Marcin Sawicki; David Thompson

2005-07-19T23:59:59.000Z

293

The $z=0.558$ absorption system towards PKS 0118-272 A candidate Damped Ly $\\alpha$ system at low redshift  

E-Print Network (OSTI)

We present a spectroscopic and imaging study of the z=0.558 MgII absorption system towards the BL Lac PKS 0118-272. At the absorber redshift we detect lines of the low ionization species MgI, MgII, CaII, TiII, MnII, and FeII. The column densities of these species are typical of the interstellar gas in the disk of the Galaxy. By assuming dust-free gas with solar abundances we infer N(HI) > 2.5 x 10^19 cm^-2. The high value of this conservative lower limit indicates that the absorber is a Damped Ly alpha system. We find [Ti/Fe] = +0.3, in agreement with [Ti/Fe] measurements in DLA absorbers, but [Mn/Fe] = +0.4, at variance with the values [Mn/Fe]2), the z=0.558 absorber seems to originate in a galaxy that has already attained the abundances and dust content of present-day disk galaxies. The analysis of our imaging data lends support to the presence of an intervening galaxy. After careful subtraction of the BL Lac image, an object at 1.6 arcsec from PKS 0118-272 is detected. At the absorber redshift the projecte...

Vladilo, G; Falomo, R; Molaro, P

1997-01-01T23:59:59.000Z

294

Converting Unconditioned Basement to Conditioned Space - Code...  

NLE Websites -- All DOE Office Websites (Extended Search)

Conditioned Space - Code Notes Converting a basement to conditioned space increases the living space of a house. As with most construction activities, the conversion or...

295

AERaSPACE CORPORATION  

Office of Legacy Management (LM)

THE ' THE ' AERaSPACE CORPORATION Suite 300, 955 L' &njon~ Pkzza. S. W., Washingvan. D.C. 200242174, Tekphanc (202) 488~6CllO 7117-03.87.cdy.43 23 September 1987 CA CA.Ot M r. Andrew Wallo, III. NE-23 Division of Facility & Site cr.05 Decommissioning Projects FL .0-d U.S. Department of Energy TAl.OL Germantown; Maryland 20545 JA/.OZ 1hJ . o-01 Dear M r. Wallo: flA.05 ELIMINATION RECOMMENDATION -- COLLEGES AND UNIVERSITIES M /4.0-* 11 D.OF The attached elimination recommendation was prepared in accordance ML.o= with your suggestion during our meeting on 22 September. The recommendation nO.o-02 includes 26 colleges and universities identified,in Enclosure 4 to Aerospace letter subject: Status of Actions - FUSRAP Site List, dated MO.03. 27 May 1987; three institutions (Tufts College, University of Virginia,

296

Hilbert space of wormholes  

E-Print Network (OSTI)

Wormhole boundary conditions for the Wheeler--DeWitt equation can be derived from the path integral formulation. It is proposed that the wormhole wave function must be square integrable in the maximal analytic extension of minisuperspace. Quantum wormholes can be invested with a Hilbert space structure, the inner product being naturally induced by the minisuperspace metric, in which the Wheeler--DeWitt operator is essentially self--adjoint. This provides us with a kind of probabilistic interpretation. In particular, giant wormholes will give extremely small contributions to any wormhole state. We also study the whole spectrum of the Wheeler--DeWitt operator and its role in the calculation of Green's functions and effective low energy interactions.

Garay, L J

1993-01-01T23:59:59.000Z

297

Exploring Lighting Spaces  

E-Print Network (OSTI)

We present a simple system for interactively specifying lighting parameters, including position, for high-quality image synthesis. Unlikeinverse approaches to the lighting-design problem, we do not require the user to indicate a priori the desired illuminative characteristics of an image. In our approach the computer proposes, culls, and organizes a set of candidate lights automatically, using an elementary measure of image similarityasthe basis for both culling and organization. The user then browses the set of candidate-light images, selects which lights to include, and combines them as desired. This work is a particular instance of a general strategy --- sampling a design space broadly and intelligently and organizing the results for rapid browsing by the user --- that may be applicable to many other design problems in computer graphics.

T. Kang; J. Seims; J. Marks; S. Shieber

1996-01-01T23:59:59.000Z

298

Transportation Market Distortions  

E-Print Network (OSTI)

Transport Prices and Markets, Victoria Transport PolicySurvey: Survey Suggests Market-Based Vision of Smart Growth,G. 1996. Roads in a Market Economy, Avebury (Aldershot).

Litman, Todd

2006-01-01T23:59:59.000Z

299

Sources of Distortion  

Science Conference Proceedings (OSTI)

..., ASM International, 2009, p 106â??126ASM Handbook, Vol 22A, Fundamentals of Modeling for Metals ProcessingD. S. MacKenzie and A. L. Banka,

300

Transportation Market Distortions  

E-Print Network (OSTI)

of Highways, Volpe National Transportation Systems Center (Evaluating Criticism of Transportation Costing, VictoriaFrom Here: Evaluating Transportation Diversity, Victoria

Litman, Todd

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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301

No Prejudice in Space  

SciTech Connect

We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in general, the LSP in our models provides a relatively small ({approx} 4%) contribution to the dark matter, however there is a long tail to this distribution and a substantial number of models for which the LSP makes up all or most of the dark matter. Typically these neutralinos are mostly Binos. Examining the signatures of our models in direct and indirect dark matter detection experiments, we find a wide range of signatures for both cases. In particular, we find a much larger range of WIMP-nucleon cross sections than is found in any particular model of SUSY-breaking. As these cross sections also enter the regions of parameter space suggested by non-SUSY models, it appears that the discovery of WIMPs in direct detection experiments might not be sufficient to determine the correct model of the underlying physics. As a first look at the signatures of these models in indirect detection experiments, we examined whether our models could explain the PAMELA excess in the positron to electron ratio at high energies. We find that there are models which fit the PAMELA data rather well, and some of these have significantly smaller boost factors than generally assumed for a thermal relic. The study of the pMSSM presents exciting new possibilities for SUSY phenomenology. The next few years will hopefully see important discoveries both in colliders and in satellite or ground-based astrophysical experiments. It is important that we follow the data and not our existing prejudices; hopefully this sort of relatively model-independent approach to collider and astrophysical phenomenology can be useful in this regard.

Cotta, R.C.; Gainer, J.S.; Hewett, J.L.; Rizzo, T.G.; /SLAC

2010-08-26T23:59:59.000Z

302

Acceptability of reactors in space  

SciTech Connect

Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it does not appear that reactors add measurably to the risk associated with the Space Transportation System.

Buden, D.

1981-01-01T23:59:59.000Z

303

Acceptability of reactors in space  

SciTech Connect

Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it dies not appear that reactors add measurably to the risk associated with the Space Transportation System.

Buden, D.

1981-04-01T23:59:59.000Z

304

Entropic Gravity in Rindler Space  

E-Print Network (OSTI)

We show that Rindler horizons are entropic screens and gravity is an entropic force in Rindler space by deriving the Verlinde entropy formula from the focusing of light due to a mass close to the horizon. Consequently, gravity is also entropic in the near horizon regions of Schwarzschild and de Sitter space-times. In different limits, the entropic nature of gravity in Rindler space leads to the Bekenstein entropy bound and the uncertainty principle.

Halyo, Edi

2011-01-01T23:59:59.000Z

305

Entropic Gravity in Rindler Space  

E-Print Network (OSTI)

We show that Rindler horizons are entropic screens and gravity is an entropic force in Rindler space by deriving the Verlinde entropy formula from the focusing of light due to a mass close to the horizon. Consequently, gravity is also entropic in the near horizon regions of Schwarzschild and de Sitter space-times. In different limits, the entropic nature of gravity in Rindler space leads to the Bekenstein entropy bound and the uncertainty principle.

Edi Halyo

2011-04-13T23:59:59.000Z

306

A characterization of separable conjugate spaces  

E-Print Network (OSTI)

Necessary and sufficient conditions for a separable Banach space to be a dual space are proved. Some applications are discussed

Rossi, Stefano

2010-01-01T23:59:59.000Z

307

Physics in discrete spaces (A): Space-Time organization  

E-Print Network (OSTI)

We put forward a model of discrete physical space that can account for the structure of space- time, give an interpretation to the postulates of quantum mechanics and provide a possible explanation to the organization of the standard model of particles.

P. Peretto

2010-12-29T23:59:59.000Z

308

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings* ........................... 3,037 115 397 384 52 1,143 22 354 64 148 357 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 386 19 43 18 11 93 7 137 8 12 38 5,001 to 10,000 .......................... 262 12 35 17 5 83 4 56 6 9 35 10,001 to 25,000 ........................ 407 20 46 44 8 151 3 53 9 19 54 25,001 to 50,000 ........................ 350 15 55 50 9 121 2 34 7 16 42 50,001 to 100,000 ...................... 405 16 57 65 7 158 2 29 6 18 45 100,001 to 200,000 .................... 483 16 62 80 5 195 1 24 Q 31 56 200,001 to 500,000 .................... 361 8 51 54 5 162 1 9 8 19 43 Over 500,000 ............................. 383 8 47 56 3 181 2 12 8 23 43 Principal Building Activity

309

Frustration by competing interactions in the highly-distorted double perovskites La2NaB'O6 (B' = Ru, Os)  

Science Conference Proceedings (OSTI)

The usual classical behaviour of S = 3/2, B-site ordered double perovskites generally results in simple, commensurate magnetic ground states. In contrast, heat capacity and neutron powder diffraction measurements for the S = 3/2 systems La2NaB'O6 (B = Ru, Os) reveal an incommensurate magnetic ground state for La2NaRuO6 and a drastically suppressed ordered moment for La2NaOsO6. This behaviour is attributed to the large monoclinic structural distortions of these double perovskites. The distortions have the effect of weakening the nearest neighbour superexchange interactions, presumably to an energy scale that is comparable to the next nearest neighbour superexchange. The exotic ground states in these materials can then arise from a competition between these two types of antiferromagnetic interactions, providing a novel mechanism for achieving frustration in the double perovskite family.

Aczel, Adam A [ORNL; Bugaris, Dan [University of South Carolina; Li, Ling [University of Tennessee, Knoxville (UTK); Yan, Jiaqiang [ORNL; Dela Cruz, Clarina R [ORNL; Zur Loye, Hans-Conrad [University of South Carolina; Nagler, Stephen E [ORNL

2013-01-01T23:59:59.000Z

310

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Revised: December, 2008 Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings ............................. 91.0 33.0 7.2 6.1 7.0 18.7 2.7 5.3 1.0 2.2 7.9 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 99.0 30.7 6.7 2.7 7.1 13.9 7.1 19.9 1.1 1.7 8.2 5,001 to 10,000 .......................... 80.0 30.1 5.5 2.6 6.1 13.6 5.2 8.2 0.8 1.4 6.6 10,001 to 25,000 ........................ 71.0 28.2 4.5 4.1 4.1 14.5 2.3 4.5 0.8 1.6 6.5 25,001 to 50,000 ........................ 79.0 29.9 6.8 5.9 6.3 14.9 1.7 3.9 0.8 1.8 7.1 50,001 to 100,000 ...................... 88.7 31.6 7.6 7.6 6.5 19.6 1.7 3.4 0.7 2.0 8.1 100,001 to 200,000 .................... 104.2 39.1 8.2 8.9 7.9 22.9 1.1 2.9 Q 3.2 8.7 200,001 to 500,000 ....................

311

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Revised: December, 2008 Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings ............................. 91.0 33.0 7.2 6.1 7.0 18.7 2.7 5.3 1.0 2.2 7.9 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 99.0 30.7 6.7 2.7 7.1 13.9 7.1 19.9 1.1 1.7 8.2 5,001 to 10,000 .......................... 80.0 30.1 5.5 2.6 6.1 13.6 5.2 8.2 0.8 1.4 6.6 10,001 to 25,000 ........................ 71.0 28.2 4.5 4.1 4.1 14.5 2.3 4.5 0.8 1.6 6.5 25,001 to 50,000 ........................ 79.0 29.9 6.8 5.9 6.3 14.9 1.7 3.9 0.8 1.8 7.1 50,001 to 100,000 ...................... 88.7 31.6 7.6 7.6 6.5 19.6 1.7 3.4 0.7 2.0 8.1 100,001 to 200,000 .................... 104.2 39.1 8.2 8.9 7.9 22.9 1.1 2.9 Q 3.2 8.7 200,001 to 500,000 ....................

312

The Beginning of the End: Hubble Space Telescope Images of Seyfert's Sextet  

E-Print Network (OSTI)

Hubble Space Telescope Wide Field Planetary Camera 2 images of Hickson Compact Group 79, Seyfert's Sextet, are presented. Both point sources and extended sources detected on the three WF chips were photometered in four filters: F336W, F439W, F555W, and F814W. Unlike other HCGs that have been imaged with HST, there do not appear to be any candidate young star clusters among the detected point sources. The majority of the point sources that may be star clusters associated with the Sextet have red colors consistent with stellar populations older than 1 Gyr. A similar conclusion is drawn with regard to the extended sources. The majority of these appear to be background galaxies, but a few candidate dwarf galaxies are identified as potentially associated with Seyfert's Sextet. However, no blue, star forming objects similar to the tidal dwarf galaxy candidates identified in other HCGs are found among the extended objects identified in this study. A redshift for one dwarf galaxy candidate was measured from a spectrum obtained with the Hobby-Eberly Telescope, and this object was found to have a redshift similar to NGC6027e, the discordant spiral formerly identified as a member of this compact group. The HST observations presented here and previous radio observations of the neutral gas content of this group suggest that the interactions that have taken place in the Sextet only redistributed the stars from the member galaxies within the group. We speculate that future interactions may be strong enough to strip the gas from NGC6027d and trigger star cluster formation.

C. Palma; S. Zonak; S. Hunsberger; J. Charlton; S. Gallagher; P. Durrell; J. English

2002-08-14T23:59:59.000Z

313

HUBBLE SPACE TELESCOPE IMAGING OF POST-STARBURST QUASARS  

Science Conference Proceedings (OSTI)

We present images of 29 post-starburst quasars (PSQs) from a Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel Snapshot program. These broadlined active galactic nuclei (AGNs) possess the spectral signatures of massive (M{sub burst} {approx} 10{sup 10} M{sub sun}), moderate-aged stellar populations (hundreds of Myr). Thus, their composite nature provides insight into the AGN-starburst connection. We measure quasar-to-host galaxy light contributions via semi-automated two-dimensional light profile fits of point-spread-function-subtracted images. We examine the host morphologies and model the separate bulge and disk components. The HST/ACS-F606W images reveal an equal number of spiral (13/29) and early-type (13/29) hosts, with the remaining three hosts having indeterminate classifications. AGNs hosted by early-type galaxies have on average greater luminosity than those hosted by spiral galaxies. Disturbances such as tidal tails, shells, star-forming knots, and asymmetries are seen as signposts of interaction/merger activity. Disturbances like these were found in 17 of the 29 objects and are evenly distributed among early-type and spiral galaxies. Two of these systems are clearly merging with their companions. Compared to other AGNs of similar luminosity and redshift, these PSQs have a higher fraction of early-type hosts and disturbances. Our most luminous objects with disturbed early-type host galaxies appear to be consistent with merger products. Thus, these luminous galaxies may represent a phase in an evolutionary scenario for merger-driven activity. Our less luminous objects appear to be consistent with Seyfert galaxies not requiring triggering by major mergers. Many of these Seyferts are barred spiral galaxies.

Cales, S. L.; Brotherton, M. S.; Shang Zhaohui [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Bennert, Vardha Nicola [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Canalizo, G. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Stoll, R. [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States); Ganguly, R. [Department of Computer Science, Engineering, and Physics, University of Michigan-Flint, Flint, MI 48502 (United States); Vanden Berk, D. [Department of Physics, Saint Vincent College, Latrobe, PA 15650 (United States); Paul, C. [Physics Department, University of California, Davis, CA 95616 (United States); Diamond-Stanic, A., E-mail: scales@uwyo.edu, E-mail: mbrother@uwyo.edu, E-mail: shang@uwyo.edu, E-mail: bennert@physics.ucsb.edu, E-mail: gabriela.canalizo@ucr.edu, E-mail: stoll@astronomy.ohio-state.edu, E-mail: ganguly@umflint.edu, E-mail: daniel.vandenberk@email.stvincent.edu, E-mail: capaul@ucdavis.edu, E-mail: aleks@ucsd.edu [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States)

2011-11-10T23:59:59.000Z

314

Upper Estimates for Banach Spaces  

E-Print Network (OSTI)

We study the relationship of dominance for sequences and trees in Banach spaces. In the context of sequences, we prove that domination of weakly null sequences is a uniform property. More precisely, if $(v_i)$ is a normalized basic sequence and $X$ is a Banach space such that every normalized weakly null sequence in $X$ has a subsequence that is dominated by $(v_i)$, then there exists a uniform constant $C\\geq1$ such that every normalized weakly null sequence in $X$ has a subsequence that is $C$-dominated by $(v_i)$. We prove as well that if $V=(v_i)_{i=1}^\\infty$ satisfies some general conditions, then a Banach space $X$ with separable dual has subsequential $V$ upper tree estimates if and only if it embeds into a Banach space with a shrinking FDD which satisfies subsequential $V$ upper block estimates. We apply this theorem to Tsirelson spaces to prove that for all countable ordinals $\\alpha$ there exists a Banach space $X$ with Szlenk index at most $\\omega^{\\alpha \\omega +1}$ which is universal for all Banach spaces with Szlenk index at most $\\omega^{\\alpha\\omega}$.

Freeman, Daniel B.

2009-08-01T23:59:59.000Z

315

The Space Infrared Interferometric Telescope (SPIRIT): High-resolution imaging and spectroscopy in the far-infrared  

E-Print Network (OSTI)

We report results of a recently-completed pre-Formulation Phase study of SPIRIT, a candidate NASA Origins Probe mission. SPIRIT is a spatial and spectral interferometer with an operating wavelength range 25 - 400 microns. SPIRIT will provide sub-arcsecond resolution images and spectra with resolution R = 3000 in a 1 arcmin field of view to accomplish three primary scientific objectives: (1) Learn how planetary systems form from protostellar disks, and how they acquire their inhomogeneous composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. Observations with SPIRIT will be complementary to those of the James Webb Space Telescope and the ground-based Atacama Large Millimeter Array. All three observatories could be operational contemporaneously.

David Leisawitz; Charles Baker; Amy Barger; Dominic Benford; Andrew Blain; Rob Boyle; Richard Broderick; Jason Budinoff; John Carpenter; Richard Caverly; Phil Chen; Steve Cooley; Christine Cottingham; Julie Crooke; Dave DiPietro; Mike DiPirro; Michael Femiano; Art Ferrer; Jacqueline Fischer; Jonathan P. Gardner; Lou Hallock; Kenny Harris; Kate Hartman; Martin Harwit; Lynne Hillenbrand; Tupper Hyde; Drew Jones; Jim Kellogg; Alan Kogut; Marc Kuchner; Bill Lawson; Javier Lecha; Maria Lecha; Amy Mainzer; Jim Mannion; Anthony Martino; Paul Mason; John Mather; Gibran McDonald; Rick Mills; Lee Mundy; Stan Ollendorf; Joe Pellicciotti; Dave Quinn; Kirk Rhee; Stephen Rinehart; Tim Sauerwine; Robert Silverberg; Terry Smith; Gordon Stacey; H. Philip Stahl; Johannes Staguhn; Steve Tompkins; June Tveekrem; Sheila Wall; Mark Wilson

2007-07-05T23:59:59.000Z

316

Integral Transforms Connecting the Hardy space with Barut-Girardello Spaces  

E-Print Network (OSTI)

We construct a one parameter family of integral transforms connecting the classical Hardy space with a class of weighted Bergman spaces called Barut-Girardello spaces.

Zouhair Mouayn

2010-03-16T23:59:59.000Z

317

Cone structure of $L^2$-Wasserstein spaces  

E-Print Network (OSTI)

In this paper, we prove that if a base space has a cone structure, then so does its $L^2$-Wasserstein space. Furthermore, we investigate relations between the base spaces of the both cones. Conversely, we show when an $L^2$-Wasserstein space has a cone structure satisfying certain conditions, then its underlying space is also a cone.

Takatsu, Asuka

2008-01-01T23:59:59.000Z

318

On Algebraic Multi-Ring Spaces  

E-Print Network (OSTI)

A Smarandache multi-space is a union of $n$ spaces $A_1,A_2,..., A_n$ with some additional conditions holding. Combining Smarandache multi-spaces with rings in classical ring theory, the conception of multi-ring spaces is introduced. Some characteristics of a multi-ring space are obtained in this paper.

Linfan Mao

2005-10-22T23:59:59.000Z

319

BNL NASA Space Radiation Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Purpose: To use beams of heavy ions provided by the Booster accelerator at Brookhaven to study the effects of simulated space radiation on biological and physical systems, with the goal of developing methods and materials to reduce the risk to human beings on prolonged space missions of the effects of ionizing radiation Sponsor: National Aeronautics and Space Administration (NASA) Project cost $34 million over 4 years Operating costs Nearly $8 million per year in 2007 Features * beams of heavy ions extracted from the Booster accelerator with masses and energies similar to the cosmic rays encountered in space: * 1-billion electron volt (GeV)/nucleon iron-56 * 0.3-GeV/nucleon gold-97 * 0.6-GeV/nucleon silicon-28 * 1-GeV/nucleon protons * 1-GeV/nucleon titanium

320

Environmental Design Space model assessment  

E-Print Network (OSTI)

The Environmental Design Space (EDS) is a multi-disciplinary design tool used to explore trade-offs among aircraft fuel burn, emissions, and noise. This thesis uses multiple metrics to assess an EDS model of a Boeing 777 ...

Spindler, Phillip Michael

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

TCP extensions for space communications  

Science Conference Proceedings (OSTI)

The space communication environment and mobile and wireless communication environments show many similarities when observed from the perspective of a transport protocol. Both types of environments exhibit loss caused by data corruption and link outage, ...

Robert C. Durst; Gregory J. Miller; Eric J. Travis

1997-10-01T23:59:59.000Z

322

Coordinate transformations in quaternion spaces  

E-Print Network (OSTI)

The quaternion spaces can be used to describe the property of electromagnetic field and gravitational field. In the quaternion space, some coordinate transformations can be deduced from the feature of quaternions, including Lorentz transformation and Galilean transformation etc., when the coordinate system is transformed into others. And some coordinate transformations with variable speed of light can be obtained in the electromagnetic field and gravitational field.

Zihua Weng

2008-08-31T23:59:59.000Z

323

Dynamical 3-Space: Emergent Gravity  

E-Print Network (OSTI)

The laws of gravitation devised by Newton, and by Hilbert and Einstein, have failed many experimental and observational tests, namely the bore hole g anomaly, flat rotation curves for spiral galaxies, supermassive black hole mass spectrum, uniformly expanding universe, cosmic filaments, laboratory G measurements, galactic EM bending, precocious galaxy formation,.. The response has been the introduction of the new epicycles: ``dark matter", ``dark energy", and others. To understand gravity we must restart with the experimental discoveries by Galileo, and following a heuristic argument we are led to a uniquely determined theory of a dynamical 3-space. That 3-space exists has been missed from the beginning of physics, although it was 1st directly detected by Michelson and Morley in 1887. Uniquely generalising the quantum theory to include this dynamical 3-space we deduce the response of quantum matter and show that it results in a new account of gravity, and explains the above anomalies and others. The dynamical theory for this 3-space involves G, which determines the dissipation rate of space by matter, and alpha, which experiments and observation reveal to be the fine structure constant. For the 1st time we have a comprehensive account of space and matter and their interaction - gravity.

Reginald T Cahill

2011-02-16T23:59:59.000Z

324

Spaces of Quantum Field Theories  

E-Print Network (OSTI)

The concept of a "space of quantum field theories" or "theory space" was set out in the 1970's in work of Wilson, Friedan and others. This structure should play an important role in organizing and classifying QFTs, and in the study of the string landscape, allowing us to say when two theories are connected by finite variations of the couplings or by RG flows, when a sequence of QFTs converges to another QFT, and bounding the amount of information needed to uniquely specify a QFT, enabling us to estimate their number. As yet we do not have any definition of theory space which can be used to make such arguments. In this talk, we will describe various concepts and tools which should be developed for this purpose, inspired by the analogous mathematical problem of studying the space of Riemannian manifolds. We state two general conjectures about the space of two-dimensional conformal field theories, and we define a distance function on this space, which gives a distance between any pair of theories, whether or not they are connected by varying moduli. Based on talks given at QTS6 (University of Kentucky), Erice, Texas A& M, and Northwestern University. To appear in the proceedings of QTS6.

Michael R. Douglas

2010-05-16T23:59:59.000Z

325

Deep Space Mission Radiation Shielding Optimization  

Science Conference Proceedings (OSTI)

Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space missions. In the present report, we ...

Tripathi R. K.; Wilson J. W.; Cucinotta F. A.; Nealy J. E.; Clowdsley M. S.; Kim M-H. Y.

2001-07-01T23:59:59.000Z

326

Sustainable Spaces Inc | Open Energy Information  

Open Energy Info (EERE)

Spaces Inc Jump to: navigation, search Name Sustainable Spaces Inc. Place San Francisco, California Zip 94103 Sector Carbon Product California-based provider of energy audits and...

327

Building Technologies Office: Simplified Space Conditioning Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

Simplified Space Conditioning Systems for Energy Efficient Homes Expert Meeting to someone by E-mail Share Building Technologies Office: Simplified Space Conditioning Systems for...

328

Building Technologies Office: Simplified Space Conditioning Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

Simplified Space Conditioning Systems for Energy Efficient Homes Expert Meeting Building America hosted the "Simplified Space Conditioning Systems for Energy Efficient Homes"...

329

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 222 194 17...

330

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,100...

331

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,928 1,316...

332

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...

333

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...

334

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...

335

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...

336

Passive Solar Space Heat | Open Energy Information  

Open Energy Info (EERE)

Solar Space Heat Jump to: navigation, search TODO: Add description List of Passive Solar Space Heat Incentives Retrieved from "http:en.openei.orgwindex.php?titlePassive...

337

Solar Space Heat | Open Energy Information  

Open Energy Info (EERE)

icon Solar Space Heat Jump to: navigation, search TODO: Add description List of Solar Space Heat Incentives Retrieved from "http:en.openei.orgwindex.php?titleSolarS...

338

Integration of space weather into space situational awareness  

SciTech Connect

Rapid assessment of space weather effects on satellites is a critical step in anomaly resolution and satellite threat assessment. That step, however, is often hindered by a number of factors including timely collection and delivery of space weather data and the inherent com plexity of space weather information. As part of a larger, integrated space situational awareness program, Los Alamos National Laboratory has developed prototype operational space weather tools that run in real time and present operators with customized, user-specific information. The Dynamic Radiation Environment Assimilation Model (DREAM) focuses on the penetrating radiation environment from natural or nuclear-produced radiation belts. The penetrating radiation environment is highly dynamic and highly orbit-dependent. Operators often must rely only on line plots of 2 MeV electron flux from the NOAA geosynchronous GOES satellites which is then assumed to be representative of the environment at the satellite of interest. DREAM uses data assimilation to produce a global, real-time, energy dependent specification. User tools are built around a distributed service oriented architecture (SOA) which will allow operators to select any satellite from the space catalog and examine the environment for that specific satellite and time of interest. Depending on the application operators may need to examine instantaneous dose rates and/or dose accumulated over various lengths of time. Further, different energy thresholds can be selected depending on the shielding on the satellite or instrument of interest. In order to rapidly assess the probability that space weather was the cause of anomalous operations, the current conditions can be compared against the historical distribution of radiation levels for that orbit. In the simplest operation a user would select a satellite and time of interest and immediately see if the environmental conditions were typical, elevated, or extreme based on how often those conditions occur in that orbit. This allows users to rapidly rule in or out environmental causes of anomalies. The same user interface can also allow users to drill down for more detailed quantitative information. DREAM can be run either from a distributed web-based user interface or as a stand-alone application for secure operations. In this paper we discuss the underlying structure of the DREAM model and demonstrate the user interface that we have developed . We also present some prototype data products and user interfaces for DREAM and discuss how space environment information can be seamlessly integrated into operational SSA systems.

Reeves, Geoffrey D [Los Alamos National Laboratory

2010-11-09T23:59:59.000Z

339

A Measurement of the Rate of type-Ia Supernovae at Redshift $z\\approx$ 0.1 from the First Season of the SDSS-II Supernova Survey  

E-Print Network (OSTI)

We present a measurement of the rate of type Ia supernovae (SNe Ia) from the first of three seasons of data from the SDSS-II Supernova Survey. For this measurement, we include 17 SNe Ia at redshift $z\\le0.12$. Assuming a flat cosmology with $\\Omega_m = 0.3=1-\\Omega_\\Lambda$, we find a volumetric SN Ia rate of $[2.93^{+0.17}_{-0.04}({\\rm systematic})^{+0.90}_{-0.71}({\\rm statistical})] \\times 10^{-5} {\\rm SNe} {\\rm Mpc}^{-3} h_{70}^3 {\\rm year}^{-1}$, at a volume-weighted mean redshift of 0.09. This result is consistent with previous measurements of the SN Ia rate in a similar redshift range. The systematic errors are well controlled, resulting in the most precise measurement of the SN Ia rate in this redshift range. We use a maximum likelihood method to fit SN rate models to the SDSS-II Supernova Survey data in combination with other rate measurements, thereby constraining models for the redshift-evolution of the SN Ia rate. Fitting the combined data to a simple power-law evolution of the volumetric SN Ia rate, $r_V \\propto (1+z)^{\\beta}$, we obtain a value of $\\beta = 1.5 \\pm 0.6$, i.e. the SN Ia rate is determined to be an increasing function of redshift at the $\\sim 2.5 \\sigma$ level. Fitting the results to a model in which the volumetric SN rate, $r_V=A\\rho(t)+B\\dot \\rho(t)$, where $\\rho(t)$ is the stellar mass density and $\\dot \\rho(t)$ is the star formation rate, we find $A = (2.8 \\pm 1.2) \\times 10^{-14} \\mathrm{SNe} \\mathrm{M}_{\\sun}^{-1} \\mathrm{year}^{-1}$, $B = (9.3^{+3.4}_{-3.1})\\times 10^{-4} \\mathrm{SNe} \\mathrm{M}_{\\sun}^{-1}$.

Benjamin Dilday; R. Kessler; J. A. Frieman; J. Holtzman; J. Marriner; G. Miknaitis; R. C. Nichol; R. Romani; M. Sako; B. Bassett; A. Becker; D. Cinabro; F. DeJongh; D. L. Depoy; M. Doi; P. M. Garnavich; C. J. Hogan; S. Jha; K. Konishi; H. Lampeitl; J. L. Marshall; D. McGinnis; J. L. Prieto; A. G. Riess; M. W. Richmond; D. P. Schneider; M. Smith; N. Takanashi; K. Tokita; K. van der Heyden; N. Yasuda; C. Zheng; J. Barentine; H. Brewington; C. Choi; A. Crotts; J. Dembicky; M. Harvanek; M. Im; W. Ketzeback; S. J. Kleinman; J. Krzesi?ski; D. C. Long; E. Malanushenko; V. Malanushenko; R. J. McMillan; A. Nitta; K. Pan; G. Saurage; S. A. Snedden; S. Watters; J. C. Wheeler; D. York

2008-01-22T23:59:59.000Z

340

Dielectric Analog Space-Times  

E-Print Network (OSTI)

We generalize the notion of a dielectric analog Schwarzschild black hole model to analog models of arbitrary space-times; in particular, the approach is not restricted to static space-times. This is done by establishing a correspondence between electrodynamics on a curved, vacuum manifold, with electrodynamics in a general linear dielectric residing in Minkowski space-time. The mapping is not unique, allowing for some freedom in the specification of equivalent materials, which could be useful for exploiting recent developments in the production of metamaterials. Some examples are considered, with special attention paid to the dielectric analog of the exterior Kerr geometry, which is found to be reproducible with regular, linear, dielectrics.

Robert T. Thompson; Jörg Frauendiener

2010-10-08T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Quantum dynamics in dual spaces  

Science Conference Proceedings (OSTI)

Quantum mechanics gives us information about spectra of dynamical variables and transition rates including scattering cross sections. They can be exhibited as spectral information in analytically continued spaces and their duals. Quantum mechanics formulated in these generalized spaces is used to study scattering and time evolution. It is shown that the usual asymptotic condition is inadequate to deal with scattering of composite or unstable particles. Scattering theory needs amendment when the interacting system is not isospectral with the free Hamiltonian, and the amendment is formulated. Perturbation theory in generalized spaces is developed and used to study the deletion and augmentation of the spectrum of the Hamiltonian. A complete set of algebraically independent constants for an interacting system is obtained. The question of the breaking of time symmetry is discussed.

Sudarshan, E.C.G.

1993-12-31T23:59:59.000Z

342

A Topological Extension of General Relativity to Explore the Nature of Quantum Space-time, Dark Energy and Inflation  

E-Print Network (OSTI)

General Relativity is extended into the quantum domain. A thought experiment is explored to derive a specific topological build-up for Planckian space-time. The presented arguments are inspired by Feynman's path integral for superposition and Wheeler's quantum foam of Planck mass mini black holes/wormholes. Paths are fundamental and prime 3-manifolds like T^3, S^1xS^2 and S^3 are used to construct quantum space-time. A physical principle is formulated that causes observed paths to multiply: It takes one to know one. So topological fluctuations on the Planck scale take the form of multiple copies of any homeomorphically distinct path through quantum space-time. The discrete time equation of motion for this topological quantum gravity is derived by counting distinct paths globally. The equation of motion is solved to derive some properties of dark energy and inflation. The dark energy density depends linearly on the number of macroscopic black holes in the universe and is time dependent in a manner consistent with current astrophysical observations, having an effective equation of state w=-1.1 for redshifts smaller than unity. Inflation driven by mini black holes proceeds over n=55 e-foldings, without strong inhomogeneity, a scalar-to-tensor ratio r=ln(7)/n=0.036 and a spectral index n_s=1-r=0.964. A discrete time effect visible in the cosmic microwave background is suggested.

Marco Spaans

2013-05-20T23:59:59.000Z

343

National Aeronautics and Space Administration SpaceMathVI  

E-Print Network (OSTI)

data. The problems were designed to be `one-pagers' with a Teacher's Guide and Answer Key as a second;Answer Key Problem 1 - How many atoms of hydrogen (H), carbon (C) and oxygen (O) are contained the planets be after 6 years? Space Math http://spacemath.gsfc.nasa.gov #12;2Answer Key Problem 1 - Students

344

Exponential Smoothing and State-Space Modeling  

Science Conference Proceedings (OSTI)

Exponential Smoothing and State-Space Modeling. Purpose: Exponential smoothing methods for forecasting are sometimes ...

2010-09-08T23:59:59.000Z

345

Some moduli spaces of Bridgeland's stability conditions  

E-Print Network (OSTI)

We shall study some moduli spaces of Bridgeland's semi-stable objects on abelian surfaces and K3 surfaces with Picard number 1. Under some conditions, we show that the moduli spaces are isomorphic to the moduli spaces of Gieseker semi-stable sheaves. We also study the ample cone of the moduli spaces.

Minamide, Hiroki; Yoshioka, Kota

2011-01-01T23:59:59.000Z

346

Free loop spaces in topology and  

E-Print Network (OSTI)

Free loop spaces in topology and physics Kathryn Hess What is the space of free loops? Enumeration of geodesics Hochschild and cyclic homology Homological conformal field theories Free loop spaces in topology Meeting of the Edinburgh Mathematical Society Glasgow, 14 November 2008 #12;Free loop spaces in topology

Thévenaz, Jacques

347

Some necessary conditions for vector space partitions  

E-Print Network (OSTI)

Some new necessary conditions for the existence of vector space partitions are derived. They are applied to the problem of finding the maximum number of spaces of dimension t in a vector space partition of V(2t,q) that contains m_d spaces of dimension d, where t/2spaces of other dimensions. It is also discussed how this problem is related to maximal partial (t-1)-spreads in V(2t,q). We also give a lower bound for the number of spaces in a vector space partition and verify that this bound is tight.

Heden, Olof

2011-01-01T23:59:59.000Z

348

XMM-Newton Surveys of the Canada-France Redshift Survey Fields - III: The Environments of X-ray Selected AGN at 0.4  

E-Print Network (OSTI)

The environmental properties of a sample of 31 hard X-ray selected AGN are investigated, from scales of 500 kpc down to 30 kpc, and are compared to a control sample of inactive galaxies. The AGN all lie in the redshift range 0.4=0 clusters. It is suggested that minor mergers with low mass companions is a likely candidate for the mechanism by which these modest luminosity AGN are fuelled.

T. J. Waskett; S. A. Eales; W. K. Gear; H. J. McCracken; S. Lilly; M. Brodwin

2005-08-03T23:59:59.000Z

349

Debris and Future Space Activities  

E-Print Network (OSTI)

Debris and Future Space Activities Prof. Joel R. Primack Physics Department University eleven year cycle, it heats the upper atmosphere and makes it expand so that debris and spacecraft in low which overflows occasionally and washes only the lowest hillsides clear of debris. Debris in orbit

California at Santa Cruz, University of

350

National Aeronautics and Space Administration  

E-Print Network (OSTI)

and Contracting Processes. Developing adequate cost estimates, managing program costs, and ensuring that NASA, simultaneously, developing the next generation of space vehicles. · Managing Risk to People, Equipment to address continued problems such as NASA's internal controls over property, plant, and equipment

Christian, Eric

351

National Aeronautics and Space Administration  

E-Print Network (OSTI)

of turbulent flow with phase transitions and radiation · Extreme weather and climate change -> is essentially and carbon with the ocean/ land/ice surface are mediated by turbulence #12;National Aeronautics and Space-Diffusivity (ED) approach In ED closure the sub-grid flux is parameterized as where k is the diffusivity

Bordoni, Simona

352

Fusion for Earth and Space  

Science Conference Proceedings (OSTI)

The compact reactor concept (Williams, 2007) has the potential to provide clean, safe and unlimited supply of energy for Earth and Space applications. The concept is a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for individual home and space power. The concept also would make it possible for each plant or remote location to have it's own power source, on site, without the need for a connection to the power grid. This would minimize, or eliminate, power blackouts. The concept could replace large fission reactors and fossil fuel power plants plus provide energy for ships, locomotives, trucks and autos. It would make an ideal source of energy for space power applications and for space propulsion.

Williams, Pharis E

2009-03-16T23:59:59.000Z

353

On Algebraic Multi-Group Spaces  

E-Print Network (OSTI)

A Smarandache multi-space is a union of $n$ spaces $A_1,A_2,..., A_n$ with some additional conditions holding. Combining classical of a group with Smarandache multi-spaces, the conception of a multi-group space is introduced in this paper, which is a generalization of the classical algebraic structures, such as the group, filed, body, $...$, etc.. Similar to groups, some characteristics of a multi-group space are obtained in this paper.

Linfan Mao

2005-10-20T23:59:59.000Z

354

Evaluation of Artifacts and Distortions of Titanium Applicators on 3.0-Tesla MRI: Feasibility of Titanium Applicators in MRI-Guided Brachytherapy for Gynecological Cancer  

Science Conference Proceedings (OSTI)

Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 {+-} 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 {+-} 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 {+-} 1.3 mm on T1-weighted MRI, whereas less than 6.9 {+-} 3.4 mm on T2-weighted MRI. No more than 1.2 {+-} 0.6 mm (3.0 {+-} 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 {+-} 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.

Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States)

2011-07-01T23:59:59.000Z

355

THE EXTENDED HUBBLE SPACE TELESCOPE SUPERNOVA SURVEY: THE RATE OF CORE COLLAPSE SUPERNOVAE TO z {approx} 1  

SciTech Connect

We use a sample of 45 core collapse supernovae detected with the Advanced Camera for Surveys on board the Hubble Space Telescope to derive the core collapse supernova rate in the redshift range 0.1 < z < 1.3. In redshift bins centered on (z) = 0.39, (z) = 0.73, and (z) = 1.11, we find rates of 3.00{sup +1.28}{sub -0.94} {sup +1.04}{sub -0.57}, 7.39{sup +1.86}{sub -1.52} {sup +3.20}{sub -1.60}, and 9.57{sup +3.76}{sub -2.80} {sup +4.96}{sub -2.80}, respectively, given in units of yr{sup -1} Mpc{sup -3} 10{sup -4} h {sup 3}{sub 70}. The rates have been corrected for host galaxy extinction, including supernovae missed in highly dust-enshrouded environments in infrared bright galaxies. The first errors are statistical while the second ones are the estimated systematic errors. We perform a detailed discussion of possible sources of systematic errors and note that these start to dominate over statistical errors at z > 0.5, emphasizing the need to better control the systematic effects. For example, a better understanding of the amount of dust extinction in the host galaxies and knowledge of the supernova luminosity function, in particular the fraction of faint M {approx}> -15 supernovae, is needed to better constrain the rates. When comparing our results with the core collapse supernova rate based on the star formation rate, we find a good agreement, consistent with the supernova rate following the star formation rate, as expected.

Dahlen, Tomas; Riess, Adam G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States); Mattila, Seppo; Kankare, Erkki [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland); Mobasher, Bahram, E-mail: dahlen@stsci.edu [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)

2012-09-20T23:59:59.000Z

356

Discrete space-time symmetries  

SciTech Connect

Symmetries have always fascinated human beings; they are found in nature, art, and architecture. Physicists, like other scientists have often used symmetries as a basis of their understanding of nature. When the dynamics is unknown, symmetries serve to delineate and define it. When the dynamics is known, symmetries are used to study structure. These two lectures review the theory and present understanding and status of two discrete space-time symmetries,, namely parity (P) and time reversal (T).

Henley, E.M.

1992-12-31T23:59:59.000Z

357

Discrete space-time symmetries  

SciTech Connect

Symmetries have always fascinated human beings; they are found in nature, art, and architecture. Physicists, like other scientists have often used symmetries as a basis of their understanding of nature. When the dynamics is unknown, symmetries serve to delineate and define it. When the dynamics is known, symmetries are used to study structure. These two lectures review the theory and present understanding and status of two discrete space-time symmetries,, namely parity (P) and time reversal (T).

Henley, E.M.

1992-01-01T23:59:59.000Z

358

National Aeronautics and Space Administration  

E-Print Network (OSTI)

Any opinions, findings, and conclusions or recommendations expressed in this volume are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration. Material in this volume may be copied without restraint for library, abstract service, education, or personal research purposes; however, republication of any paper or portion thereof requires the written permission of the authors as well as the appropriate acknowledgment of this publication. Abstracts in this volume may be cited as

Curt Niebur; Nasa Headquarters; Terry Hurford; Nasa Goddard; Curt Niebur; Nasa Headquarters

2007-01-01T23:59:59.000Z

359

TCP Extensions for Space Communications  

E-Print Network (OSTI)

The space communication environment and mobile and wireless communication environments show many similarities when observed from the perspective of a transport protocol. Both types of environments exhibit loss caused by data corruption and link outage, in addition to congestion-related loss. The constraints imposed by the two environments are also similar --- power, weight, and physical volume of equipment are scarce resources. Finally, it is not uncommon for communication channel data rates to be severely limited and highly asymmetric. We are working on solutions to these types of problems for space communication environments, and we believe that these solutions may be applicable to the mobile and wireless community. As part of our work, we have defined and implemented the Space Communications Protocol Standards-Transport Protocol (SCPSTP) , a set of extensions to TCP that address the problems that we have identified. The results of our performance tests, both in the laboratory and on actual satellites, indicate that the SCPS-TP extensions yield significant improvements in throughput over unmodified TCP on error-prone links. Additionally, the SCPS modifications significantly improve performance over links with highly asymmetric data rates.

Robert C. Durst; Gregory J. Miller; Eric J. Travis

1996-01-01T23:59:59.000Z

360

Embeddings and factorizations of Banach spaces  

E-Print Network (OSTI)

One problem, considered important in Banach space theory since at least the 1970’s, asks for intrinsic characterizations of subspaces of a Banach space with an unconditional basis. A more general question is to give necessary and sufficient conditions for operators from Lp (2 space, being a subspace of a reflexive space with an unconditional basis or being a quotient of such a space, is equivalent to having the unconditional tree property. I also show that a bounded linear operator from Lp (2 spaces.

Zheng, Bentuo

2007-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Effects of distortion of the intercluster motion in {sup 2}H, {sup 3}He, {sup 3}H, {sup 6}Li, and {sup 9}Be on Trojan horse applications  

Science Conference Proceedings (OSTI)

Deuteron induced quasifree scattering and reactions have been extensively investigated in the past few decades as well as {sup 6}Li, {sup 3}H, {sup 3}He, and {sup 9}Be induced reactions. This was done not only for the investigation of nuclear structure and reaction mechanisms but also for important astrophysical applications (Trojan horse method). In particular the widths of the spectator momentum distributions in several nuclei, which have been used as Trojan horses, have been obtained as a function of the transferred momentum. Applications of Trojan horse method will also be discussed because the momentum distribution of the spectator particle inside the nucleus is a important input for this method. This gives hints on distortion effects at low energies important for nuclear astrophysics.

Pizzone, R. G.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Romano, S. [Laboratori Nazionali del Sud-INFN, Catania (Italy); Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania, Catania (Italy); Mukhamedzhanov, A. M. [Cyclotron Institute, Texas A and M University, College Station (United States); Blokhintsev, L. D. [Moscow State University, Moscow (Russian Federation); Bertulani, C. A. [Physics Department, Texas A and M University, Commerce (United States); Irgaziev, B. F. [GIK Institute of Engineering Sciences and Technology, Topi, District Swabi, N. W. F. P. (Pakistan)

2009-08-15T23:59:59.000Z

362

Color spaces in digital video  

SciTech Connect

Whether it`s photography, computer graphics, publishing, or video; each medium has a defined color space, or gamut, which defines the extent that a given set of RGB colors can be mixed. When converting from one medium to another, an image must go through some form of conversion which maps colors into the destination color space. The conversion process isn`t always straight forward, easy, or reversible. In video, two common analog composite color spaces are Y`tjv (used in PAL) and Y`IQ (used in NTSC). These two color spaces have been around since the beginning of color television, and are primarily used in video transmission. Another analog scheme used in broadcast studios is Y`, R`-Y`, B`-Y` (used in Betacam and Mll) which is a component format. Y`, R`-Y`,B`-Y` maintains the color information of RGB but in less space. From this, the digital component video specification, ITU-Rec. 601-4 (formerly CCIR Rec. 601) was based. The color space for Rec. 601 is symbolized as Y`CbCr. Digital video formats such as DV, Dl, Digital-S, etc., use Rec. 601 to define their color gamut. Digital composite video (for D2 tape) is digitized analog Y`UV and is seeing decreased use. Because so much information is contained in video, segments of any significant length usually require some form of data compression. All of the above mentioned analog video formats are a means of reducing the bandwidth of RGB video. Video bulk storage devices, such as digital disk recorders, usually store frames in Y`CbCr format, even if no other compression method is used. Computer graphics and computer animations originate in RGB format because RGB must be used to calculate lighting and shadows. But storage of long animations in RGB format is usually cost prohibitive and a 30 frame-per-second data rate of uncompressed RGB is beyond most computers. By taking advantage of certain aspects of the human visual system, true color 24-bit RGB video images can be compressed with minimal loss of visual information. For example, humans `see` more white-to-black (luminance) detail then red, green, or blue color detail. Also, the eye is most sensitive to green colors. Taking advantage of this, both composite and component video allocates more bandwidth for the luma (Y`) signal than the chroma signals. Y`611 is composed of 59% green`, 30% red`, and 11% blue` (prime symbol denotes gamma corrected colors). This luma signal also maintains compatibility with black and white television receivers. Component digital video converts R`G`B` signals (either from a camera or a computer) to a monochromatic brightness signal Y` (referred here as luma to distinguish it from the CIE luminance linear- light quantity), and two color difference signals Cb and Cr. These last two are the blue and red signals with the luma component subtracted out. As you know, computer graphic images are composed of red, green, and blue elements defined in a linear color space. Color monitors do not display RGB linearly. A linear RGB color space image must be gamma corrected to be displayed properly on a CRT. Gamma correction, which is approximately a 0.45 power function, must also be employed before converting an RGB image to video color space. Gamma correction is defined for video in the international standard: ITU-Rec. BT.709-4. The gamma correction transform is the same for red, green, and blue. The color coding standard for component digital video and high definition video symbolizes gamma corrected luma by Y`, the blue difference signal by Cb (Cb = B` -Y`), and the red color difference signal by Cr (Cr = R` - Y`). Component analog HDTV uses Y`PbPr. To reduce conversion errors, clip in R`G`B`, not in Y`CbCr space. View video on a video monitor, computer monitor phosphors are wrong. Use a large word size (double precision) to avoid warp around, the0232n round the results to values between 0 and 255. And finally, recall that multiplying two 8- bit numbers results in a 16-bit number, so values need to be clipped to 8-bits.

Gaunt, R.

1997-05-01T23:59:59.000Z

363

Small Space Heater Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Small Space Heater Basics Small Space Heater Basics Small Space Heater Basics August 19, 2013 - 10:38am Addthis Small space heaters, also called portable heaters, are typically used when the main heating system is inadequate or when central heating is too costly to install or operate. Space heater capacities generally range between 10,000 Btu to 40,000 Btu per hour. Common fuels used for this purpose are electricity, propane, natural gas, and kerosene. Although most space heaters rely on convection (the circulation of air in a room), some rely on radiant heating; that is, they emit infrared radiation that directly heats up objects and people that are within their line of sight. Combustion Space Heaters Space heaters are classified as vented and unvented, or "vent free." Unvented combustion units are not recommended for inside use, as they

364

Precipitation from Space: Advancing Earth System Science  

Science Conference Proceedings (OSTI)

Advances to space-based observing systems and data processing techniques have made precipitation datasets quickly and easily available via various data portals and widely used in Earth sciences. The increasingly lengthy time span of space-based ...

Paul A. Kucera; Elizabeth E. Ebert; F. Joseph Turk; Vincenzo Levizzani; Dalia Kirschbaum; Francisco J. Tapiador; Alexander Loew; M. Borsche

2013-03-01T23:59:59.000Z

365

Defining digital space through a visual language  

E-Print Network (OSTI)

Current approaches toward digital spaces mainly mimic the physical space that surrounds us. While this approach is valid in a wide range of applications and research, the goal of this thesis is to propose an alternative ...

Kilian, Axel, 1971-

2000-01-01T23:59:59.000Z

366

A WRINKLE IN SPACE Christopher Adam Cross  

E-Print Network (OSTI)

committee. ii #12;Abstract Christopher Adam Cross We explore notions of curvature of regular surfaces be made between distant points in space and time by curving space until the two points touch. I would

367

Cyber-Physical Challenges for Space Systems  

Science Conference Proceedings (OSTI)

Modern space systems necessarily have a tight coupling between onboard cyber (processing, communication) and physical (sensing, actuation) elements to survive the harsh extraterrestrial environment and successfully complete ambitious missions. This article ... Keywords: attitude control, communication, robotics, space systems

Andrew T. Klesh; James W. Cutler; Ella M. Atkins

2012-04-01T23:59:59.000Z

368

Solar space heating | Open Energy Information  

Open Energy Info (EERE)

heating heating Jump to: navigation, search (The following text is derived from the United States Department of Energy's description of solar space heating technology.)[1] Contents 1 Space Heating 2 Passive Solar Space Heating 3 Active Solar Space Heating 4 References Space Heating A solar space-heating system can consist of a passive system, an active system, or a combination of both. Passive systems are typically less costly and less complex than active systems. However, when retrofitting a building, active systems might be the only option for obtaining solar energy. Passive Solar Space Heating Passive solar space heating takes advantage of warmth from the sun through design features, such as large south-facing windows, and materials in the floors or walls that absorb warmth during the day and release that warmth

369

Mapping densities in a noisy state space  

E-Print Network (OSTI)

Weak noise smooths out fractals in a chaotic state space and introduces a maximum attainable resolution to its structure. The balance of noise and deterministic stretching/contraction in each neighborhood introduces local invariants of the dynamics that can be used to partition the state space. We study the local discrete-time evolution of a density in a two-dimensional hyperbolic state space, and use the asymptotic eigenfunctions for the noisy dynamics to formulate a new state space partition algorithm.

Domenico Lippolis

2013-03-05T23:59:59.000Z

370

National Aeronautics and Space Administration Technologies ...  

National Aeronautics and Space Administration Technologies Available for Licensing ... solar system and universe beyond; ... power, energy storage and conversion, ...

371

All Universal Coverings Are Spanier Spaces  

E-Print Network (OSTI)

In this paper, we study necessary and sufficient conditions for existence of categorical universal coverings using open covers of a given space $X$. In fact, we define several homotopy theoretic conditions which we then prove are equivalent to the existence of a categorical universal covering space. As an application, we show that all universal coverings of a connected and locally path connected space are Spanier spaces.

Pakdaman, Ali; Mashayekhy, Behrooz

2011-01-01T23:59:59.000Z

372

Atomic Power in Space: A History  

DOE R&D Accomplishments (OSTI)

"Atomic Power in Space," a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. Interplanetary space exploration successes and achievements have been made possible by this technology, for which there is no known substitue.

1987-03-00T23:59:59.000Z

373

Exploring indoor white spaces in metropolises  

Science Conference Proceedings (OSTI)

It is a promising vision to utilize white spaces, i.e., vacant VHF and UHF TV channels, to satisfy skyrocketing wireless data demand in both outdoor and indoor scenarios. While most prior works have focused on exploring outdoor white spaces, the indoor ... Keywords: TV white spaces, clustering algorithms, sensor placement

Xuhang Ying, Jincheng Zhang, Lichao Yan, Guanglin Zhang, Minghua Chen, Ranveer Chandra

2013-09-01T23:59:59.000Z

374

Space-Conditioning System Selection Guide  

Science Conference Proceedings (OSTI)

This handbook represents a single-source guide to the selection of space-conditioning equipment for commercial facilities. Written for the utility marketing representative, it provides information on these topics: heating, cooling, ventilation, and dehumidification requirements of commercial buildings; customer needs when selecting a space-conditioning system; and, the options among energy-efficient electric space-conditioning systems for commercial buildings.

1994-01-22T23:59:59.000Z

375

Efficient optimal design space characterization methodologies  

Science Conference Proceedings (OSTI)

One of the primary advantages of a high-level synthesis system is its ability to explore the design space. This paper presents several methodologies for design space exploration that compute all optimal tradeoff points for the combined ... Keywords: bounding, clock-length determination, design space exploration, efficient searching, high-level synthesis, module selection, scheduling

Stephen A. Blythe; Robert A. Walker

2000-07-01T23:59:59.000Z

376

On the design of potential collaboration spaces  

Science Conference Proceedings (OSTI)

In this paper, we introduce the concepts of Potential and Actual Collaboration Spaces. The former applies to the initial space where opportunities for collaboration are identified and an initial interaction is established, while the latter relates to ... Keywords: Doc2U, casual and informal interactions, potential collaboration awareness, potential collaboration spaces

Alberto L. Moran; Jesus Favela; Ana M. Martinez Enriquez; Dominique Decouchant

2004-05-01T23:59:59.000Z

377

Atomic power in space: A history  

Science Conference Proceedings (OSTI)

''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs.

Not Available

1987-03-01T23:59:59.000Z

378

State-space least mean square  

Science Conference Proceedings (OSTI)

In this paper, we present a generalized form of the well-known least mean square (LMS) filter. The proposed filter incorporates linear time-varying state-space model of the underlying environment and hence is termed as state-space LMS (SSLMS). This attribute ... Keywords: Adaptive filtering, SSLMS, State-space LMS, Tracking

Mohammad Bilal Malik; Muhammad Salman

2008-05-01T23:59:59.000Z

379

COTS-based applications in space avionics  

Science Conference Proceedings (OSTI)

The use of commercial electronic components is increasingly attractive for the space domain. This paper discusses the current degree of use of these components in space avionics, the selection and qualification phases to be successfully completed before ... Keywords: COTS, commercial electronic components, disruptive technology, fault-tolerant architectures, performance limitation, space avionics

Michel Pignol

2010-03-01T23:59:59.000Z

380

Earthwatch: The climate from space  

SciTech Connect

This concise textbook shows how observations from satellites can be used to derive variables important to the monitoring of the climate system. The aim of this book is not to provide a rigorous treatment of climate or of remote sensing and instrumentation, but to attempt to integrate the different disciplines at a level appropriate for undergraduate students of meteorology. The general topics covered are as follows: components of the climate system, basic physical laws (radiations and radiative transfer), current climate issues (greenhouse effect, ozone depletion, Southern Oscillations), remote sensing techniques, and operational principles of sensors aboard space platforms.

Harries, J.E.

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Free-space quantum cryptography  

Science Conference Proceedings (OSTI)

An experimental free-space quantum key distribution (QKD) system has been tested over an outdoor optical path of {approximately}1 km under nighttime conditions at Los Alamos National Laboratory. This system employs the Bennett 92 protocol; here the authors give a brief overview of this protocol, and describe the experimental implementation of it. An analysis of the system efficiency is presented, as well as a description of the error detection protocol, which employs a two-dimensional parity check scheme. Finally, the susceptibility of this system to eavesdropping by various techniques is determined. Possible applications include the rekeying of satellites in low earth orbit.

Hughes, R.J.; Buttler, W.T.; Kwiat, P.G.; Lamoreaux, S.K.; Morgan, G.L.; Nordholt, J.E.; Peterson, C.G.

1998-12-31T23:59:59.000Z

382

BigBOSS: The Ground-Based Stage IV BAO Experiment  

DOE Green Energy (OSTI)

The BigBOSS experiment is a proposed DOE-NSF Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with an all-sky galaxy redshift survey. The project is designed to unlock the mystery of dark energy using existing ground-based facilities operated by NOAO. A new 4000-fiber R=5000 spectrograph covering a 3-degree diameter field will measure BAO and redshift space distortions in the distribution of galaxies and hydrogen gas spanning redshifts from 0.2< z< 3.5. The Dark Energy Task Force figure of merit (DETF FoM) for this experiment is expected to be equal to that of a JDEM mission for BAO with the lower risk and cost typical of a ground-based experiment.

Schlegel, David; Bebek, Chris; Heetderks, Henry; Ho, Shirley; Lampton, Michael; Levi, Michael; Mostek, Nick; Padmanabhan, Nikhil; Perlmutter, Saul; Roe, Natalie; Sholl, Michael; Smoot, George; White, Martin; Dey, Arjun; Abraham, Tony; Jannuzi, Buell; Joyce, Dick; Liang, Ming; Merrill, Mike; Olsen, Knut; Salim, Samir

2009-04-01T23:59:59.000Z

383

Better bases for kernel spaces  

E-Print Network (OSTI)

In this article we investigate the feasibility of constructing stable, local bases for computing with kernels. In particular, we are interested in constructing families $(b_{\\xi})_{\\xi\\in\\Xi}$ that function as bases for kernel spaces $S(k,\\Xi)$ so that each basis function is constructed using very few kernels. In other words, each function $b_{\\zeta}(x) = \\sum_{\\xi\\in\\Xi} A_{\\zeta,\\xi} k(x,\\xi)$ is a linear combination of samples of the kernel with few nonzero coefficients $A_{\\zeta,\\xi}$. This is reminiscent of the construction of the B-spline basis from the family of truncated power functions. We demonstrate that for a large class of kernels (the Sobolev kernels as well as many kernels of polyharmonic and related type) such bases exist. In fact, the basis elements can be constructed using a combination of roughly $O(\\log N)^d$ kernels, where $d$ is the local dimension of the manifold and $N$ is the dimension of the kernel space (i.e. $N=#\\Xi$). Viewing this as a preprocessing step -- the construction of the...

Fuselier, E J; Narcowich, F J; Ward, J D; Wright, G B

2011-01-01T23:59:59.000Z

384

Interferometric imaging of the high-redshift radio galaxy, 4C60.07: An SMA, Spitzer and VLA study reveals a binary AGN/starburst  

E-Print Network (OSTI)

High-resolution submm imaging of the HzRG, 4C60.07, at z=3.8, has revealed two dusty components. Spitzer imaging shows that one of these components (B) is coincident with an extremely red AGN, offset by ~4" (~30 kpc) from the HzRG core. The other submm component (A) - resolved by our beam and devoid of emission at 3.6-8.0um - lies between B and the HzRG core. Since the HzRG was discovered via its young, steep-spectrum lobes and their creation was likely triggered by the interaction, we argue that we are witnessing an early-stage merger, prior to its eventual equilibrium state. The interaction is between the host galaxy of an actively-fueled BH, and a gas-rich starburst/AGN (B) marked by the compact submm component and coincident with broad CO emission. `A' is a plume of cold, dusty gas, associated with a narrow (~150 km/s) CO feature, and may represent a short-lived tidal structure. It has been claimed that HzRGs and SMGs differ only in the activity of their AGNs, but such complex submm morphologies are seen only rarely amongst SMGs. Our study has important implications: where a galaxy's gas is not aligned with its central BH, CO may be an unreliable probe of dynamical mass, affecting work on the co-assembly of BHs and spheroids. Our data support the picture wherein close binary AGN are induced by mergers. They also raise the possibility that some supposedly jet-induced starbursts may have formed co-evally with (yet independently of) the radio jets, both triggered by the same interaction. We note that the HzRG host would have gone unnoticed without its jets/companion, so there may be many other unseen BHs at high redshift, lost in the sea of ~5 x 10^8 similarly bright IRAC sources - sufficiently massive to drive a >10^27-W radio source, yet practically invisible unless actively fueled (abridged).

R. J. Ivison; G. E. Morrison; A. D. Biggs; Ian Smail; S. P. Willner; M. A. Gurwell; T. R. Greve; J. A. Stevens; M. L. N. Ashby

2008-08-15T23:59:59.000Z

385

Solar space heating | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Solar space heating (Redirected from - Solar Ventilation Preheat) Jump to: navigation, search (The following text is derived from the United States Department of Energy's description of solar space heating technology.)[1] Contents 1 Space Heating 2 Passive Solar Space Heating 3 Active Solar Space Heating 4 References Space Heating A solar space-heating system can consist of a passive system, an active system, or a combination of both. Passive systems are typically less costly and less complex than active systems. However, when retrofitting a building, active systems might be the only option for obtaining solar

386

Quantum L_p and Orlicz spaces  

E-Print Network (OSTI)

Let $\\A$ ($\\cM$) be a $C^*$-algebra (a von Neumann algebra respectively). By a quantum dynamical system we shall understand the pair $({\\A}, T)$ ($({\\cM}, T)$) where $T : {\\A} \\to {\\A}$ ($T : {\\cM} \\to {\\cM}$) is a linear, positive (normal respectively), and identity preserving map. In our lecture, we discuss how the techniques of quantum Orlicz spaces may be used to study quantum dynamical systems. To this end, we firstly give a brief exposition of the theory of quantum dynamical systems in quantum $L_p$ spaces. Secondly, we describe the Banach space approach to quantization of classical Orlicz spaces. We will discuss the necessity of the generalization of $L_p$-space techniques. Some emphasis will be put on the construction of non-commutative Orlicz spaces. The question of lifting dynamical systems defined on von Neumann algebra to a dynamical system defined in terms of quantum Orlicz space will be discussed.

L. E. Labuschagne; W. A. Majewski

2009-02-25T23:59:59.000Z

387

Before House Committee on Science, Space, and Technology | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Space, and Technology Before House Committee on Science, Space, and Technology Before House Committee on Science, Space, and Technology By: Peter Lyons Subject: Assessing America's...

388

Before House Committee on Science, Space and Technology | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Space and Technology Before House Committee on Science, Space and Technology Before House Committee on Science, Space and Technology By: Secretary Steven Chu Subject: FY 2013...

389

Before the House Committee on Science, Space and Technology ...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the House Committee on Science, Space and Technology Before the House Committee on Science, Space and Technology Statement Before the Committee on Science, Space and Technology,...

390

Survivable pulse power space radiator  

DOE Patents (OSTI)

A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

Mims, J.; Buden, D.; Williams, K.

1988-03-11T23:59:59.000Z

391

Data structure as topological spaces  

E-Print Network (OSTI)

Abstract. In this paper, we propose a topological metaphor for computations: computing consists in moving through a path in a data space and making some elementary computations along this path. This idea underlies an experimental declarative programming language called mgs. mgs introduces the notion of topological collection: a set of values organized by a neighborhood relationship. The basic computation step in mgs relies on the notion of path: a path C is substituted for a path B in a topological collection A. This step is called a transformation and several features are proposed to control the transformation applications. By changing the topological structure of the collection, the underlying computational model is changed. Thus, mgs enables a unified view on several computational mechanisms. Some of them are initially inspired by biological or chemical processes (Gamma and the CHAM, Lindenmayer systems, Paun systems and cellular automata).

Jean-louis Giavitto; Olivier Michel

2002-01-01T23:59:59.000Z

392

Space Power Systems | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactor Technologies » Space Power Systems Reactor Technologies » Space Power Systems Space Power Systems Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration. Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration. The Department of Energy (DOE) and its predecessors have provided radioisotope power systems that have safely enabled deep space exploration and national security missions for five decades. Radioisotope power systems (RPSs) convert the heat from the decay of the radioactive isotope plutonium-238 (Pu-238) into electricity. RPSs are capable of producing heat and electricity under the harsh conditions

393

Space reactors - past, present, and future  

SciTech Connect

In the 1990s and beyond, advanced-design nuclear reactors could represent the prime source of both space power and propulsion. Many sophisticated military and civilian space missions of the future will require first kilowatt and then megawatt levels of power. This paper reviews key technology developments that accompanied past US space nuclear power development efforts, describes on-going programs, and then explores reactor technologies that will satisfy megawatt power level needs and beyond.

Buden, D.; Angelo, J.

1983-01-01T23:59:59.000Z

394

Moduli spaces of PU(2)-monopoles  

E-Print Network (OSTI)

The goal of this article was the S^1-equivariant transversality-problem and the compactification-problem for the moduli spaces of (perturbed) PU(2)-monopoles. A substantially improved version entitled "Moduli spaces of PU(2)-monopoles (revised version)" which gives simpler, clearer proofs of the transversality results, has been published on arxiv in June 99 and appeared in Asian J. Math, see Moduli spaces of PU(2)-Monopoles, Asian J. Math. Vol. 4, No. 2 (2000), 391-436.

Andrei Teleman

1997-02-07T23:59:59.000Z

395

Upgrading Below-Grade Spaces: Assessing Priorities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Below-Grade Spaces: Below-Grade Spaces: Assessing Priorities Sam Breidenbach [Cold climate bias] Gap-Balancing risk and homeowner expectations * Managing risk and challenges for contractors - Moisture, mold and liability - Durability/Sustainability - Design/build vs. owner's architect - Contract language to reduce liability - Aligning technical details with specific situations - Below grade spaces are business opportunities - Selling and Competition Gap-Balancing risk and homeowner expectations * Homeowner Expectations and Priorities - Focused on "house beautiful" until technical failure occurs - Health related issues - Opportunity to conserve energy - Cost vs. value-"inexpensive additional space" - Expectations not aligned with physical realities.

396

Models for multimegawatt space power systems  

SciTech Connect

This report describes models for multimegawatt, space power systems which Sandia's Advanced Power Systems Division has constructed to help evaluate space power systems for SDI's Space Power Office. Five system models and models for associated components are presented for both open (power system waste products are exhausted into space) and closed (no waste products) systems: open, burst mode, hydrogen cooled nuclear reactor -- turboalternator system; open, hydrogen-oxygen combustion turboalternator system; closed, nuclear reactor powered Brayton cycle system; closed, liquid metal Rankine cycle system; and closed, in-core, reactor therminonic system. The models estimate performance and mass for the components in each of these systems. 17 refs., 8 figs., 15 tabs.

Edenburn, M.W.

1990-06-01T23:59:59.000Z

397

Section D: SPACE HEATING - Energy Information Administration  

U.S. Energy Information Administration (EIA)

2001 Residential Energy Consumption Survey Form EIA-457A (2001)--Household Questionnaire OMB No.: 1905-0092, Expiring February 29, 2004 19 Section D: SPACE HEATING

398

National Aeronautics and Space Administration Technology ...  

National Aeronautics and Space Administration Technology Marketing Summaries. Here you’ll find marketing summaries for technologies available for licensing from the ...

399

Wider benefits of Space Science & Exploration  

E-Print Network (OSTI)

, batteries, fuel cells, supercapacitors (nuclear) · High impact technologies · Miniature systems · Facilities power sources Deep space missions Improved weather forecasting Climate monitoring Vehicle systems

Anand, Mahesh

400

User interfaces in space science instrumentation .  

E-Print Network (OSTI)

??This thesis examines user interaction with instrumentation in the specific context of space science. It gathers together existing practice in machine interfaces with a look… (more)

McCalden, A.J.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Perspectives in Fundamental Physics in Space  

E-Print Network (OSTI)

We discuss the fundamental principles underlying the current physical theories and the prospects of further improving their knowledge through experiments in space.

Orfeu Bertolami; Clovis Jacinto de Matos; Jean Christophe Grenouilleau; Olivier Minster; Sergio Volonte

2004-05-07T23:59:59.000Z

402

Testbed Environment for Space Situational Awareness (TESSA)  

TESSA is a parallelized discrete event simulation for large-scale modeling and simulation of space events in a high performance computing environment.

403

Moduli spaces of PU(2)-monopoles  

E-Print Network (OSTI)

We study the S^1-equivariant transversality-problem and the compactification-problem for the moduli spaces of (perturbed) PU(2)-monopoles.

Andrei Teleman

1997-02-07T23:59:59.000Z

404

Space-time thermodynamics of the glass transition  

E-Print Network (OSTI)

Space-time Thermodynamics of the Glass Transition Maurobehavior in terms of a thermodynamics of trajectory space.

Merolle, Mauro; Garrahan, Juan P.; Chandler, David

2005-01-01T23:59:59.000Z

405

Chaotic eigenfunctions in phase space  

E-Print Network (OSTI)

We study individual eigenstates of quantized area-preserving maps on the 2-torus which are classically chaotic. In order to analyze their semiclassical behavior, we use the Bargmann-Husimi representations for quantum states, as well as their stellar parametrization, which encodes states through a minimal set of points in phase space (the constellation of zeros of the Husimi density). We rigorously prove that a semiclassical uniform distribution of Husimi densities on the torus entails a similar equidistribution for the corresponding constellations. We deduce from this property a universal behavior for the phase patterns of chaotic Bargmann eigenfunctions, which reminds of the WKB approximation for eigenstates of integrable systems (though in a weaker sense). In order to obtain more precise information on ``chaotic eigenconstellations", we then model their properties by ensembles of random states, generalizing former results on the 2-sphere to the torus geometry. This approach yields statistical predictions for the constellations, which fit quite well the chaotic data. We finally observe that specific dynamical information, e.g. the presence of high peaks (like scars) in Husimi densities, can be recovered from the knowledge of a few long-wavelength Fourier coefficients, which therefore appear as valuable order parameters at the level of individual chaotic eigenfunctions.

S. Nonnenmacher; A. Voros

1997-11-15T23:59:59.000Z

406

Is Interstellar Space Travel Possible?  

E-Print Network (OSTI)

It is shown that space travel, even in the most distant future, will remain confined to our own planetary system, and a similar conclusion will hold forth for any other civilization, no matter how advanced it might be, unless those extra-terrestrial species have life spans order of magnitude longer than ours. Even in such a case it is unlikely that they will travel much farther than their immediate stellar neighbourhood, as each such excursion will exhaust the resources of their home planet so much that those will dwindle rather fast and there might not be much left for the further scientific and technological advancements. So the science-fiction fancy of a "Galactic Empire" may ever remain in our fantasies only. And as for the mythical UFOs, whose quiet appearances do get reported in the press once in a while, recent explorations have shown no evidence that any such thing could have an origination within our own solar system itself. And a "quiet trip" back and forth from a distant star is almost impossible a...

Singal, Tanmay

2013-01-01T23:59:59.000Z

407

Towards a routing framework in ad hoc space networks  

Science Conference Proceedings (OSTI)

A routing framework called Space Gateway Routing (SGR) is proposed for routing through Autonomous Regions (ARs) in ad hoc space networks. SGR has two integral parts: External SGR (ESGR) and Interior SGR (ISGR). ESGR ... Keywords: ad hoc networks, autonomous regions, contact allocation, data delivery, inter-region message scheduling, remote control messages, space communications, space gateway routing, space missions, space networks

Chao Chen; Zesheng Chen

2010-12-01T23:59:59.000Z

408

THE GREENLAND FLOW DISTORTION EXPERIMENT  

Science Conference Proceedings (OSTI)

Greenland has a major influence on the atmospheric circulation of the North Atlantic–western European region, dictating the location and strength of mesoscale weather systems around the coastal seas of Greenland and directly influencing synoptic-...

I. A. Renfrew; G. N. Petersen; S. Outten; D. Sproson; G. W. K. Moore; C. Hay; T. Ohigashi; S. Zhang; J. E. Kristjánsson; I. Føre; H. Ólafsson; S. L. Gray; E. A. Irvine; K. Bovis; P. R. A. Brown; R. Swinbank; T. Haine; A. Lawrence; R. S. Pickart; M. Shapiro; A. Woolley

2008-09-01T23:59:59.000Z

409

Influence of Cooling on Distortion  

Science Conference Proceedings (OSTI)

Table 11   Factors that influence the cooling intensity of liquid quenchants...the vapor pressure is, the more difficult the

410

Distortion Representation of Forecast Errors  

Science Conference Proceedings (OSTI)

Forecast error is decomposed into three components, termed displacement error, amplitude error, mid residual error, respectively. Displacement error measures how much of the forecast error can be accounted for by moving the forecast to best fit ...

Ross N. Hoffman; Zheng Liu; Jean-Francois Louis; Christopher Grassoti

1995-09-01T23:59:59.000Z

411

Reclaiming residual space from elevated transport infrastructure : time, space, and activity under the Chicago Brown Line  

E-Print Network (OSTI)

This thesis studies the non-transport functions of the residual space generated by elevated transport infrastructure and its relationship with abutting neighborhoods The space under the Chicago Brown Line, among all other ...

Su, Jing, S.M. Massachusetts Institute of Technology

2005-01-01T23:59:59.000Z

412

Design principles for the development of space technology maturation laboratories aboard the International Space Station  

E-Print Network (OSTI)

This thesis formulates seven design principles for the development of laboratories which utilize the International Space Station (ISS) to demonstrate the maturation of space technologies. The principles are derived from ...

Saenz Otero, Alvar, 1975-

2005-01-01T23:59:59.000Z

413

Building a time- and space-partitioned architecture for the next generation of space vehicle avionics  

Science Conference Proceedings (OSTI)

Future space systems require innovative computing system architectures, on account of their size, weight, power consumption, cost, safety and maintainability requisites. The AIR (ARINC 653 in Space Real-Time Operating System) architecture answers the ...

José Rufino; João Craveiro; Paulo Verissimo

2010-10-01T23:59:59.000Z

414

Optimized Shielding for Space Radiation Protection  

Science Conference Proceedings (OSTI)

Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and ...

Wilson J. W.; Cucinotta F. A.; Kim M-H. Y.; Schimmerling W.

2000-05-01T23:59:59.000Z

415

Electrostatic Climber for Space Elevator and Launcher  

E-Print Network (OSTI)

Author details research on the new, very prospective, electrostatic Space Elevator climber based on a new electrostatic linear engine previously offered at the 42nd Joint Propulsion Conference (AIAA-2006-5229) and published in AEAT, Vol.78, No.6, 2006, pp. 502-508. The electrostatic climber discussed can have any speed (and braking), the energy for climber movement is delivered by a lightweight high-voltage line into a Space Elevator-holding cable from Earth electric generator. This electric line also can be used for delivery electric energy to a Geosynchronous Space Station. At present, the best solution of the climber problem (announced by NASA as one important awarding problem of Space Elevator) is problematic. Author also shows the linear electrostatic engine may be used as realistic power space launcher at the present time. Two projects illustrate these new devices. Key words: Space elevator, Electrostatic climber for space elevator, Electrostatic space launcher, Electrostatic accelerator. This work is presented as paper AIAA-2007-5838 for 43 Joint Propulsion Conference, Cincinnati, Ohio, USA, 9-11 July, 2007,

A. Bolonkin

2007-05-14T23:59:59.000Z

416

TV white-space for smart grid  

Science Conference Proceedings (OSTI)

Inability to obtain frequency spectrum for meeting the surge in demand for wireless solutions has been a worldwide problem. The recent advancement in TV White Space (TVWS), which uses frequency spectrum opportunistically when the incumbent users are ... Keywords: TV white-space, advanced metering infrastructure, cognitive radio, smart grid

Ser Wah Oh; Francois Chin; See Gim Kerk

2011-10-01T23:59:59.000Z

417

State space representation of routing flexibility  

Science Conference Proceedings (OSTI)

This paper describes a state space representation for sequencing and routing flexibility in manufacturing systems. Routing flexibility is represented using five different stages as follows: (i) Precedence Graph of Operations; (ii) State Transition Graph ... Keywords: Flexible manufacturing systems, Routing flexibility, Sequencing flexibility, State space representation

Leonardo Rosa Rohde; Denis Borenstein

2005-12-01T23:59:59.000Z

418

Gravity in Complex Hermitian Space-Time  

E-Print Network (OSTI)

A generalized theory unifying gravity with electromagnetism was proposed by Einstein in 1945. He considered a Hermitian metric on a real space-time. In this work we review Einstein's idea and generalize it further to consider gravity in a complex Hermitian space-time.

Ali H. Chamseddine

2006-10-09T23:59:59.000Z

419

Space directed coils for biological objectives  

Science Conference Proceedings (OSTI)

There are given different constructions of electromagnetic coils for using in biomedicine. There are developed constructions of space directed coils for increasing and decreasing the growth of cells in biology and medicine. Keywords: biological objectives, coils, decreasing, growth, increasing, space-directed

V. I. Vlastopulo

2010-07-01T23:59:59.000Z

420

Modular Reconfigurable Robots in Space Applications  

Science Conference Proceedings (OSTI)

Robots used for tasks in space have strict requirements. Modular reconfigurable robots have a variety of attributes that are well suited to these conditions, including: serving as many different tools at once (saving weight), packing into compressed ... Keywords: locomotion, modular, robot, self-reconfigurable, snake robot, space

Mark Yim; Kimon Roufas; David Duff; Ying Zhang; Craig Eldershaw; Sam Homans

2003-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Beta decays with momentum space Majorana spinors  

E-Print Network (OSTI)

We construct and apply to beta decays a truly neutral local quantum field that is entirely based upon momentum space Majorana spinors. We make the observation that theory with momentum space Majorana spinors of real C parities is equivalent to Dirac's theory. For imaginary C parities, the neutrino mass can drop from the single beta decay trace and reappear in 0\

M. Kirchbach; C. Compean; L. Noriega

2004-11-24T23:59:59.000Z

422

Machine learning in space: extending our reach  

Science Conference Proceedings (OSTI)

We introduce the challenge of using machine learning effectively in space applications and motivate the domain for future researchers. Machine learning can be used to enable greater autonomy to improve the duration, reliability, cost-effectiveness, and ... Keywords: Autonomy, Machine learning applications, Space missions

Amy Mcgovern; Kiri L. Wagstaff

2011-09-01T23:59:59.000Z

423

Quantum Mechanics and Multiply Connected Spaces  

E-Print Network (OSTI)

t is well known that the difference between Quantum Mechanics and Classical Theory appears most crucially in the non Classical spin half of the former theory and the Wilson-Sommerfelt quantization rule. We argue that this is symptomatic of the fact that Quantum Theory is actually a theory in multiply connected space while Classical Theory operates in simply connected space.

B. G. Sidharth

2006-05-16T23:59:59.000Z

424

Mutual information aspects of scale space images  

Science Conference Proceedings (OSTI)

In image registration, mutual information is a well-performing measure based on principles of uncertainty. Similarly, in image analysis the Gaussian scale space, based on minimal assumptions of the image, is used to derive intrinsic properties of an ... Keywords: Entropy, Image analysis, Image structure, Multiresolution, Mutual information, Registration, Scale space

A. Kuijper

2004-12-01T23:59:59.000Z

425

Lab celebrates 50 years in space  

NLE Websites -- All DOE Office Websites (Extended Search)

celebrates 50 years in space celebrates 50 years in space Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit Lab celebrates 50 years in space National security missions and pure research December 1, 2013 Lab celebrates 50 years in space Lab's instruments have helped detect possible nuclear weapon detonations and led to fundamental scientific discoveries. Contacts Community Programs Office Director Kurt Steinhaus Email Editor Linda Anderman Email Not only does 2013 mark the Lab's 70th anniversary, it also marks the 50th anniversary of its first mission into space. During those five decades, it's been involved in 206 launches-only a few other organizations in the world can claim more-that began with the goal of helping monitor compliance with the 1963 Partial Test Ban Treaty through

426

Space nuclear power: a strategy for tomorrow  

SciTech Connect

Energy: reliable, portable, abundant and low cost will be a most critical factor, perhaps the sine qua non, for the unfolding of man's permanent presence in space. Space-based nuclear power, in turn, is a key technology for developing such space platforms and the transportation systems necessary to service them. A strategy for meeting space power requirements is the development of a 100-kW(e) nuclear reactor system for high earth orbit missions, transportation from Shuttle orbits to geosynchronous orbit, and for outer planet exploration. The component technology for this nuclear power plant is now underway at the Los Alamos National Laboratory. As permanent settlements are established on the Moon and in space, multimegawatt power plants will be needed. This would involve different technology similar to terrestrial nuclear power plants.

Buden, D.; Angelo, J. Jr.

1981-01-01T23:59:59.000Z

427

TREES AND BRANCHES IN BANACH SPACES  

E-Print Network (OSTI)

Abstract. An infinite dimensional notion of asymptotic structure is considered. This notion is developed in terms of trees and branches on Banach spaces. Every countably infinite countably branching tree T of a certain type on a space X is presumed to have a branch with some property. It is shown that then X can be embedded into a space with an FDD (Ei) so that all normalized sequences in X which are almost a skipped blocking of (Ei) have that property. As an application of our work we prove that if X is a separable reflexive Banach space and for some 1 0, there exists a finite codimensional subspace of X which C 2 + ? embeds into the ?p sum of finite dimensional spaces. 1.

E. Odell; Th. Schlumprecht

2000-01-01T23:59:59.000Z

428

Twistors and antipodes in de Sitter space  

E-Print Network (OSTI)

We develop the basics of twistor theory in de Sitter space, up to the Penrose transform for free massless fields. We treat de Sitter space as fundamental, as one does for Minkowski space in conventional introductions to twistor theory. This involves viewing twistors as spinors of the de Sitter group SO(4,1). When attached to a spacetime point, such a twistor can be reinterpreted as a local SO(3,1) Dirac spinor. Our approach highlights the antipodal map in de Sitter space, which gives rise to doublings in the standard relations between twistors and spacetime. In particular, one can generate a field with both handedness signs from a single twistor function. Such fields naturally live on antipodally-identified de Sitter space dS_4/Z_2, which has been put forward as the ideal laboratory for quantum gravity with positive cosmological constant.

Neiman, Yasha

2013-01-01T23:59:59.000Z

429

Radiation Effects in the Space Telecommunications Environment  

SciTech Connect

Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space.

Fleetwood, Daniel M.; Winokur, Peter S.

1999-05-17T23:59:59.000Z

430

Medical Applications of Space Light-Emitting Diode Technology--Space Station and Beyond  

SciTech Connect

Space light-emitting diode (LED) technology has provided medicine with a new tool capable of delivering light deep into tissues of the body, at wavelengths which are biologically optimal for cancer treatment and wound healing. This LED technology has already flown on Space Shuttle missions, and shows promise for wound healing applications of benefit to Space Station astronauts.

Whelan, H.T.; Houle, J.M.; Donohoe, D.L.; Bajic, D.M.; Schmidt, M.H.; Reichert, K.W.; Weyenberg, G.T.; Larson, D.L.; Meyer, G.A.; Caviness, J.A.

1999-06-01T23:59:59.000Z

431

Space Logistics Modeling and Simulation Analysis using SpaceNet: Four Application Cases  

E-Print Network (OSTI)

The future of space exploration will not be limited to sortie-style missions to single destinations. Even in present exploration taking place at the International Space Station in low-Earth orbit, logistics is complicated by flights arriving from five launch sites on Earth. The future challenges of space logistics given complex campaigns of interconnected missions in deep space will require innovative tools to aid planning and conceptual design. This paper presents a modeling framework to evaluate the propulsive and logistics feasibility of space exploration from the macro-logistics perspective, which covers the delivery of elements and resources to support demands generated during exploration. The modeling framework is implemented in a versatile and unifying software tool, SpaceNet, for general space exploration scenario analysis. Four space exploration scenarios are presented as application cases to highlight the applicability of the framework across vastly different scenarios. The first case investigates the resupply of the International Space Station between 2010 and 2015 using 77 missions combining NASA, European Space Agency, Japanese Space Agency, Russian Space Agency, and commercial space transportation. The second case models a lunar outpost build-up consisting of 17 flights to achieve continuous human presence over eight years. The third case models and evaluates a conceptual sortie-style mission to a near-Earth object, 1999 AO10. Finally, the fourth case models a flexible path type human exploration in the vicinity of Mars using a combination of human and tele-operated exploration. Taken together these cases demonstrate the challenges and logistical requirements of future human space exploration campaigns during the period from 2010-2050 and illustrate the ability of SpaceNet to model and simulate the feasibility of meeting these requirements. I.

Paul T. Grogan; Howard K. Yue; Olivier L. De Weck

2011-01-01T23:59:59.000Z

432

Geothermal Energy: Residential Space Heating  

DOE Green Energy (OSTI)

The purpose of this study, which was carried out under the auspices of the DGRST, was to determine the best way to use geothermal hot water for residential space heating. It quickly became apparent that the type of heating apparatus used in the housing units was most important and that heat pumps could be a valuable asset, making it possible to extract even more geothermal heat and thus substantially improve the cost benefit of the systems. Many factors play a significant role in this problem. Therefore, after a first stage devoted to analyzing the problem through a manual method which proved quite useful, the systematic consideration of all important aspects led us to use a computer to optimize solutions and process a large number of cases. The software used for this general study can also be used to work out particular cases: it is now available to any interested party through DGRST. This program makes it possible to: (1) take climatic conditions into account in a very detailed manner, including temperatures as well as insolation. 864 cases corresponding to 36 typical days divided into 24 hours each were chosen to represent the heating season. They make it possible to define the heating needs of any type of housing unit. (2) simulate and analyze the behavior in practice of a geothermal heating system when heat is extracted from the well by a simple heat exchanger. This simulation makes it possible to evaluate the respective qualities of various types of heating apparatus which can be used in homes. It also makes it possible to define the best control systems for the central system and substations and to assess quite accurately the presence of terminal controls, such as radiators with thermostatically controlled valves. (3) determine to what extent the addition of a heat pump makes it possible to improve the cost benefit of geothermal heating. When its average characteristics and heating use conditions (price, coefficient of performance, length of utilization, electrical rates, etc.) are taken into account, the heat pump should not be scaled for maximum heating power. Consequently, the program considers several possible sizes, with different installation schemes, and selects for each case the value which corresponds to the lowest cost of heating.

None

1977-03-01T23:59:59.000Z

433

HUBBLE SPACE TELESCOPE NARROWBAND SEARCH FOR EXTENDED Ly{alpha} EMISSION AROUND TWO z > 6 QUASARS  

Science Conference Proceedings (OSTI)

We search for extended Ly{alpha} emission around two z > 6 quasars, SDSS J1030+0524 (z = 6.309) and SDSS J1148+5251 (z = 6.419) using Wide Field Camera 3 narrowband filters on board the Hubble Space Telescope. For each quasar, we collected two deep, narrowband images, one sampling the Ly{alpha} line+continuum at the quasar redshifts and one of the continuum emission redward of the line. After carefully modeling the point-spread function, we find no evidence for extended Ly{alpha} emission. These observations set 2{sigma} limits of L(Ly{alpha}, extended) rates typically inferred from (rest-frame) far-infrared measurements of z {approx} 6 quasars, these limits are well below the intrinsic bright Ly{alpha} emission expected from the recombination of gas photoionized by the quasars or by the star formation in the host galaxies, and point toward significant Ly{alpha} suppression or dust attenuation. However, small extinction values have been observed along the line of sight to the nuclei, thus reddening has to be coupled with other mechanisms for Ly{alpha} suppression (e.g., resonance scattering). No Ly{alpha} emitting companions are found, down to a 5{sigma} sensitivity of {approx}1 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} arcsec{sup -2} (surface brightness) and {approx}5 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} (assuming point sources).

Decarli, Roberto; Walter, Fabian; Yang Yujin; Hennawi, Joseph F.; Rix, Hans-Walter; Venemans, Bram P. [Max-Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Carilli, Chris L. [NRAO, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States); Fan Xiahoui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Kurk, Jaron [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Riechers, Dominik [Astronomy Department, Caltech, 1200 East California boulevard, Pasadena, CA 91125 (United States); Strauss, Michael A., E-mail: decarli@mpia.de [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)

2012-09-10T23:59:59.000Z

434

The Hardy Space $H^1$ on Non-homogeneous Metric Spaces  

E-Print Network (OSTI)

Let $({\\mathcal X}, d, \\mu)$ be a metric measure space and satisfy the so-called upper doubling condition and the geometrical doubling condition. In this paper, we introduce the atomic Hardy space $H^1(\\mu)$ and prove that its dual space is the known space ${\\rm RBMO}(\\mu)$ in this context. Using this duality, we establish a criterion for the boundedness of linear operators from $H^1(\\mu)$ to any Banach space. As an application of this criterion, we obtain the boundedness of Calder\\'on--Zygmund operators from $H^1(\\mu)$ to $L^1(\\mu)$.

Hytönen, Tuomas; Yang, Dongyong

2010-01-01T23:59:59.000Z

435

Hubble Space Telescope Imaging of the Circumnuclear Environments of the CfA Seyfert Galaxies: Nuclear Spirals and Fueling  

E-Print Network (OSTI)

We present archival Hubble Space Telescope images of the nuclear regions of 43 of the 46 Seyfert galaxies found in the volume-limited, spectroscopically-complete CfA Redshift Survey sample. Using an improved method of image contrast enhancement, we create detailed high-quality structure maps that allow us to study the distributions of dust, star clusters, and emission-line gas in the circumnuclear regions (100-1000 pc scales) and in the associated host galaxy. Essentially all of these Seyfert galaxies have circumnuclear dust structures with morphologies ranging from grand-design two-armed spirals to chaotic dusty disks. In most Seyferts there is a clear physical connection between the nuclear dust spirals on hundreds of parsec scales and large-scale bars and spiral arms in the host galaxies proper. These connections are particularly striking in the interacting and barred galaxies. Such structures are predicted by numerical simulations of gas flows in barred and interacting galaxies, and may be related to the fueling of AGN by matter inflow from the host galaxy disks. We see no significant differences in the circumnuclear dust morphologies of Seyfert 1s and 2s, and very few Seyfert 2 nuclei are obscured by large-scale dust structures in the host galaxies. If Seyfert 2s are obscured Seyfert 1s, then the obscuration must occur on smaller scales than those probed by HST.

Richard W. Pogge; Paul Martini

2002-01-11T23:59:59.000Z

436

MEASURING THE SOLAR RADIUS FROM SPACE DURING THE 2003 AND 2006 MERCURY TRANSITS  

Science Conference Proceedings (OSTI)

The Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory observed the transits of Mercury on 2003 May 7 and 2006 November 8. Contact times between Mercury and the solar limb have been used since the seventeenth century to derive the Sun's size but this is the first time that high-quality imagery from space, above the Earth's atmosphere, has been available. Unlike other measurements, this technique is largely independent of optical distortion. The true solar radius is still a matter of debate in the literature as measured differences of several tenths of an arcsecond (i.e., about 500 km) are apparent. This is due mainly to systematic errors from different instruments and observers since the claimed uncertainties for a single instrument are typically an order of magnitude smaller. From the MDI transit data we find the solar radius to be 960.''12 {+-} 0.''09 (696, 342 {+-} 65 km). This value is consistent between the transits and consistent between different MDI focus settings after accounting for systematic effects.

Emilio, M. [Observatorio Astronomico-Departamento de Geociencias, Universidade Estadual de Ponta Grossa, Parana (Brazil); Kuhn, J. R.; Scholl, I. F. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI 96822 (United States); Bush, R. I., E-mail: memilio@uepg.br, E-mail: kuhn@ifa.hawaii.edu, E-mail: ifscholl@hawaii.edu, E-mail: rock@sun.stanford.edu [Hansen Experimental Physics Laboratory (HEPL), Stanford University, Stanford, CA 94305 (United States)

2012-05-10T23:59:59.000Z

437

Illumination of interior spaces by bended hollow light guides: Application of the theoretical light propagation method  

SciTech Connect

To ensure comfort and healthy conditions in interior spaces the thermal, acoustics and daylight factors of the environment have to be considered in the building design. Due to effective energy performance in buildings the new technology and applications also in daylight engineering are sought such as tubular light guides. These allow the transport of natural light into the building core reducing energy consumption. A lot of installations with various geometrical and optical properties can be applied in real buildings. The simplest set of tubular light guide consists of a transparent cupola, direct tube with high reflected inner surface and a ceiling cover or diffuser redistributing light into the interior. Such vertical tubular guide is often used on flat roofs. When the roof construction is inclined a bend in the light guide system has to be installed. In this case the cupola is set on the sloped roof which collects sunlight and skylight from the seen part of the sky hemisphere as well as that reflected from the ground and opposite facades. In comparison with the vertical tube some additional light losses and distortions of the propagated light have to be expected in bended tubular light guides. Recently the theoretical model of light propagation was already published and its applications are presented in this study solving illuminance distributions on the ceiling cover interface and further illuminance distribution on the working plane in the interior. (author)

Darula, Stanislav; Kocifaj, Miroslav; Kittler, Richard [ICA, Slovak Academy of Sciences, Bratislava (Slovakia); Kundracik, Frantisek [Department of Experimental Physics, FMPI, Comenius University, Bratislava (Slovakia)

2010-12-15T23:59:59.000Z

438

Using standard Internet Protocols and applications in space  

Science Conference Proceedings (OSTI)

This paper discusses approaches for using standard Internet technologies to meet the communication needs of future space missions. It summarizes work done by the Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC since 1997. That ... Keywords: Internet in space, Internet space missions, Space communication protocols, Space shuttle STS-107, Spacecraft networking

Keith Hogie; Ed Criscuolo; Ron Parise

2005-04-01T23:59:59.000Z

439

Space-Time Insight | Open Energy Information  

Open Energy Info (EERE)

Space-Time Insight Space-Time Insight Jump to: navigation, search Name Space-Time Insight Address 45680 Northport Loop East Place Fremont, California Zip 94538 Sector Efficiency Product SpaceTime Awareness Server Year founded 2008 Number of employees 11-50 Website http://www.spacetimeinsight.co Coordinates 37.4923832°, -121.9532879° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.4923832,"lon":-121.9532879,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

440

Vortex tracking in scale-space  

Science Conference Proceedings (OSTI)

Scale-space techniques have become popular in computer vision for their capability to access the multiscale information inherently contained in images. We show that the field of flow visualization can benefit from these techniques, too, yielding more ...

Dirk Bauer; Ronald Peikert

2002-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "redshift space distortions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Social catalysts : embracing communication in mediated spaces  

E-Print Network (OSTI)

Mediated communication between public spaces is a relatively new concept. One current example of this interaction is video conferencing among people within the same organization. Large scale video-conferencing walls have ...

Karahalios, Kyratso G., 1972-

2004-01-01T23:59:59.000Z

442

Dutch Space BV | Open Energy Information  

Open Energy Info (EERE)

Space BV Space BV Jump to: navigation, search Name Dutch Space BV Place Leiden, Netherlands Zip 2333 Sector Solar Product Leiden-based supplier of subsystems for the European space industry, including the production of solar arrays for spacecraft. Coordinates 52.15457°, 4.49463° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":52.15457,"lon":4.49463,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

443

Securing Public Space [Awards Jury Commentaries  

E-Print Network (OSTI)

suited to the EDRA/Places awards. Yet—except for one entry,absent from this year’s awards cycle. Those who design,Vale / Securing Public Space Awards Jury Commentaries Places

Vale, Lawrence J

2005-01-01T23:59:59.000Z

444

Scatterometer Data Interpretation: Measurement Space and Inversion  

Science Conference Proceedings (OSTI)

The geophysical interpretation of the radar measurements from the ERS-1 scatterometer, called ?0, is considered. An important tool in the interpretation of the data is the visualization of the triplets of radar backscatter in measurement space. ...

Ad Stoffelen; David Anderson

1997-12-01T23:59:59.000Z

445

Climate Monitoring from Space: Asynoptic Sampling Considerations  

Science Conference Proceedings (OSTI)

Monitoring climate variability from space is considered from the standpoint of satellite sampling. Asynoptic sampling leads to well-defined limits in spatial and temporal resolution which are violated by behavior involving sufficiently small ...

Murry L. Salby

1989-09-01T23:59:59.000Z

446

Reinterpretation of space in a networked community  

E-Print Network (OSTI)

One of the most significant reasons why architects dwell on the design of a space is because we believe that the physical environment will influence social and interpersonal relationships. Recognizing the limitations in ...

Park, Kat Suejung, 1973-

2003-01-01T23:59:59.000Z

447

SloanSpace- DSpace file transfer component  

E-Print Network (OSTI)

This thesis demonstrates how to use Web services to integrate course management systems with digital repositories. We present a component that provides interoperation between SloanSpace, a course management system, and ...

Cuevas, Genevieve T

2005-01-01T23:59:59.000Z

448

Spacing innovation and learning in design organizations  

E-Print Network (OSTI)

The main research question of this thesis is the following: What is the relationship between spaces and innovation in the context of design organizations such as IDEO, the MIT Media Lab and Design Continuum? This thesis ...

García Herrera, Cristóbal, 1974-

2004-01-01T23:59:59.000Z

449

Open Space Stewardship Program 2013 Celebration  

Energy.gov (U.S. Department of Energy (DOE))

Students in grades K through 12 are involved in authentic environmental research on properties in their own communities, fostering a sense of ownership and responsibility for open space within...

450

Kinetic modeling of electrodynamic space tethers  

E-Print Network (OSTI)

Electrodynamic space tethers provide propellant-less orbit boosting and de-orbiting of Low Earth Orbit (LEO) satellites. On the one hand, when driven by a current, their interaction with the Earth's magnetic field creates ...

Deux, Jean-Marie A

2005-01-01T23:59:59.000Z

451

State-Space Modeling for Atmospheric Pollution  

Science Conference Proceedings (OSTI)

Two different aspect concerning the state-space modeling for atmospheric pollution are dealt with separately in this paper: (i) the treatment of the advection-diffusion equation and (ii) the use of time series analysis.

E. Hernández; F. Martín; F. Valero

1991-06-01T23:59:59.000Z

452

Cargo revenue management for space logistics  

E-Print Network (OSTI)

This thesis covers the development of a framework for the application of revenue management, specifically capacity control, to space logistics for use in the optimization of mission cargo allocations, which in turn affect ...

Armar, Nii A

2009-01-01T23:59:59.000Z

453

Effects as functions on projective Hilbert space  

E-Print Network (OSTI)

The set of effect operators in a complex Hilbert space can be injectively embedded into the set of functions from the set of one-dimensional projections to the real interval [0,1]. Properties of this injection are investigated.

P. Busch; S. P. Gudder

2013-03-26T23:59:59.000Z

454

Generalized integrability conditions and target space geometry  

E-Print Network (OSTI)

In some higher dimensional nonlinear field theories integrable subsectors with infinitely many conservation laws have been identified by imposing additional integrability conditions. Originally, the complex eikonal equation was chosen as integrability condition, but recently further generalizations have been proposed. Here we show how these new integrability conditions may be derived from the geometry of the target space and, more precisely, from the Noether currents related to a certain class of target space transformations.

C. Adam; J. Sanchez-Guillen

2005-08-01T23:59:59.000Z

455

Flying on Sun Shine: Sailing in Space  

SciTech Connect

On January 20th, 2011, NanoSail-D succes