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1

GLAST Observatory Renamed for Fermi, Reveals Entire Gamma-Ray Sky |  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of Energy Power.pdf11-161-LNG | Department of Energy Freeport LNGEnergy

2

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope  

ScienceCinema (OSTI)

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008.  In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Isabelle Grenier

2010-01-08T23:59:59.000Z

3

Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas  

E-Print Network [OSTI]

Fermi gases, collections of fermions such as neutrons and electrons, are found throughout nature, from solids to neutron stars. Interacting Fermi gases can form a superfluid or, for charged fermions, a superconductor. We ...

Ku, Mark Jen-Hao

4

NEW FERMI-LAT EVENT RECONSTRUCTION REVEALS MORE HIGH-ENERGY GAMMA RAYS FROM GAMMA-RAY BURSTS  

SciTech Connect (OSTI)

Based on the experience gained during the four and a half years of the mission, the Fermi-LAT Collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet finalized, we can test the improvements in the new event reconstruction with the special case of the prompt phase of bright gamma-ray bursts (GRBs), where the signal-to-noise ratio is large enough that loose selection cuts are sufficient to identify gamma rays associated with the source. Using the new event reconstruction, we have re-analyzed 10 GRBs previously detected by the Large Area Telescope (LAT) for which an X-ray/optical follow-up was possible and found four new gamma rays with energies greater than 10 GeV in addition to the seven previously known. Among these four is a 27.4 GeV gamma ray from GRB 080916C, which has a redshift of 4.35, thus making it the gamma ray with the highest intrinsic energy ({approx}147 GeV) detected from a GRB. We present here the salient aspects of the new event reconstruction and discuss the scientific implications of these new high-energy gamma rays, such as constraining extragalactic background light models, Lorentz invariance violation tests, the prompt emission mechanism, and the bulk Lorentz factor of the emitting region.

Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Baldini, L. [Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bregeon, J.; Pesce-Rollins, M.; Sgro, C.; Tinivella, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Chekhtman, A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Cohen-Tanugi, J. [Laboratoire Univers et Particules de Montpellier, Universite Montpellier 2, CNRS/IN2P3, F-34095 Montpellier (France); Drlica-Wagner, A.; Omodei, N.; Rochester, L. S.; Usher, T. L. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Granot, J. [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Ra'anana 43537 (Israel); Longo, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Razzaque, S. [Department of Physics, University of Johannesburg, Auckland Park 2006 (South Africa); Zimmer, S., E-mail: melissa.pesce.rollins@pi.infn.it, E-mail: nicola.omodei@stanford.edu, E-mail: granot@openu.ac.il [Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden)

2013-09-01T23:59:59.000Z

5

Remembering Fermi  

SciTech Connect (OSTI)

A combination of the discovery of nuclear fission and the circumstances of the 2nd World War brought Enrico Fermi to Chicago, where he led the team that produced the first controlled, self-sustained nuclear chain reaction. Following the war in 1945 Chancellor Hutchins, William Zachariasen, and Walter Bartky convinced Fermi to accept a professorship at the University of Chicago, where the Institute for Nuclear Studies was established. Fermi served as the leading figure in surely the greatest collection of scientists the world has ever seen. Fermi's tenure at Chicago was cut short by his death in 1954. My talk will concentrate on the years 1945-54. Examples of his research notebooks, his speeches, his teaching, and his correspondence will be discussed.

Cronin, James (Enrico Fermi Institute, University of Chicago) [Enrico Fermi Institute, University of Chicago

2005-03-30T23:59:59.000Z

6

Building Address Locations -Assumes entire  

E-Print Network [OSTI]

Building Address Locations - Assumes entire building unless noted Designation Submit through* 560, 4 BU Crosstown Center 801 Massachusetts Ave Floor 1, 2 BMC BCD Building 800 Harrison Avenue BCD BMC Biosquare III 670 Albany Floors 2, 3, 6, 7 BMC Biosquare III 670 Albany Floors 1, 4, 5, 8 BU Building

Guenther, Frank

7

Fermi Observations of Gamma-ray Bursts  

SciTech Connect (OSTI)

The gamma-ray emission mechanism of Gamma-ray bursts (GRBs) are still unknown. Fermi Gamma-ray Space Telescope successfully detected high-energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high-energy emission. These new observational results are driving many theoretical implications, such as leptonic, hadronic and afterglow origin. The highest energy photon detected by Fermi gives a constraint on the bulk Lorentz factor of the ultra-relativistic jets of GRBs. The impact of the Fermi GRB observations extends not only to the GRB-related issues but also to the outside GRB physics, such as quantum gravity and model of the extra galactic background light.

Ohno, Masanori [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

2010-10-15T23:59:59.000Z

8

Michigan Nuclear Profile - Fermi  

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

Fermi" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

9

Analysing the Entire Wikipedia History with Database Supported Haskell  

E-Print Network [OSTI]

Analysing the Entire Wikipedia History with Database Supported Haskell George Giorgidze1 , Torsten the entire Wikipedia history. DSH is a novel high-level database query facility allowing for the for on our experience of using Database Supported Haskell (DSH) [4] for analysing the entire history

Grust, Torsten

10

A notable family of entire intrinsic minimal graph...  

E-Print Network [OSTI]

to C1(O). This notion of C2 surface obviously includes the entire intrinsic graphs ...... F. Serra Cassano, Surface measures in Carnot-Carathéodory spaces, Calc.

2006-09-09T23:59:59.000Z

11

Ultracold Fermi gas with repulsive interactions  

E-Print Network [OSTI]

This thesis presents results from experiments of ultracold atomic Fermi gases with repulsive interaction. Itinerant ferromagnetism was studied by simulating the Stoner model with a strongly interacting Fermi gas of ultracold ...

Lee, Ye-Ryoung

2012-01-01T23:59:59.000Z

12

Extremely Correlated Fermi Liquids B. Sriram Shastry  

E-Print Network [OSTI]

Extremely Correlated Fermi Liquids B. Sriram Shastry Physics Department, University of California the theory of an extremely correlated Fermi liquid with U ! 1. This liquid has an underlying auxiliary Fermi liquid Green's function that is further caparisoned by extreme correlations. The theory leads to two

California at Santa Cruz, University of

13

Entirely passive heat pipe apparatus capable of operating against gravity  

DOE Patents [OSTI]

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 meters and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, Daniel R. (Santa Fe, NM)

1982-01-01T23:59:59.000Z

14

Enrico Fermi and the Dolomites  

E-Print Network [OSTI]

Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the next generations, in particular in the first half of the XX century, and the group of via Panisperna was directly connected: Edoardo Amaldi, the son of the mathematician Ugo sr., rented at least during two summers, in 1925 and in 1949, and in the winter of 1960, a house in San Vito di Cadore, and almost every year in the Dolomites; Enrico Fermi was a frequent guest. Many important steps in modern physics, in particular the development of the Fermi-Dirac statistics and the Fermi theory of beta decay, are related to scientific discussions held in the region of the Dolomites.

Giovanni Battimelli; Alessandro De Angelis

2014-07-15T23:59:59.000Z

15

Fermi Timing and Synchronization System  

SciTech Connect (OSTI)

The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.

Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F.X.; Kim, J.; Chen, J.; Ilday, F.O.; Ludwig, F.; Winter, A.; Ferianis, M.; Danailov, M.; D'Auria, G.

2006-07-19T23:59:59.000Z

16

Fermi liquid theory for high temperature superconductors  

SciTech Connect (OSTI)

In this article the Fermi liquid theory of metals is discussed starting from Luttinger's theorem. The content of Luttinger's Theorem and its implications for microscopic theories of high temperature superconductors are discussed. A simple quasi-2d Fermi liquid theory is introduced and some of its properties are calculated. It is argued that a number of experiments on YBa/sub 2/Cu/sub 3/O/sub 6+x/, x > 0.5, strongly suggest the existence of a Fermi surface and thereby a Fermi liquid normal state. 25 refs., 1 fig.

Bedell, K.S.

1988-01-01T23:59:59.000Z

17

PROSPECTS FOR GRB SCIENCE WITH THE FERMI LARGE AREA TELESCOPE  

SciTech Connect (OSTI)

The Large Area Telescope (LAT) instrument on the Fermi mission will reveal the rich spectral and temporal gamma-ray burst (GRB) phenomena in the >100 MeV band. The synergy with Fermi's Gamma-ray Burst Monitor detectors will link these observations to those in the well explored 10-1000 keV range; the addition of the >100 MeV band observations will resolve theoretical uncertainties about burst emission in both the prompt and afterglow phases. Trigger algorithms will be applied to the LAT data both onboard the spacecraft and on the ground. The sensitivity of these triggers will differ because of the available computing resources onboard and on the ground. Here we present the LAT's burst detection methodologies and the instrument's GRB capabilities.

Band, D. L. [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Axelsson, M. [Stockholm Observatory, Albanova, SE-106 91 Stockholm (Sweden); Baldini, L.; Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Battelino, M. [Department of Physics, Royal Institute of Technology (KTH), AlbaNova, SE-106 91 Stockholm (Sweden); Bissaldi, E. [Max-Planck Institut fuer extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany); Bogaert, G. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Bonnell, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chiang, J.; Do Couto e Silva, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94305 (United States); Cohen-Tanugi, J. [Laboratoire de Physique Theorique et Astroparticules, Universite Montpellier 2, CNRS/IN2P3, Montpellier (France); Connaughton, V. [University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Cutini, S. [Agenzia Spaziale Italiana (ASI) Science Data Center, I-00044 Frascati (Roma) (Italy); De Palma, F. [Dipt. di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy); Dingus, B. L. [Los Alamos National Lab., Los Alamos, NM 87545 (United States); Fishman, G. [NASA Marshall Space Flight Center, Huntsville, AL 35805 (United States)], E-mail: nicola.omodei@pi.infn.it (and others)

2009-08-20T23:59:59.000Z

18

Prospects for GRB Science with the Fermi Large Area Telescope  

E-Print Network [OSTI]

The LAT instrument on the Fermi mission will reveal the rich spectral and temporal gamma-ray burst phenomena in the > 100 MeV band. The synergy with Fermi's GBM detectors will link these observations to those in the well explored 10-1000 keV range; the addition of the > 100 MeV band observations will resolve theoretical uncertainties about burst emission in both the prompt and afterglow phases. Trigger algorithms will be applied to the LAT data both onboard the spacecraft and on the ground. The sensitivity of these triggers will differ because of the available computing resources onboard and on the ground. Here we present the LAT's burst detection methodologies and the instrument's GRB capabilities.

Band, D L; Baldini, L; Barbiellini, G; Baring, M G; Bastieri, D; Battelino, M; Bellazzini, R; Bissaldi, E; Bogaert, G; Bonnel, J; Chiang, J; Cohen-Tanugi, J; Connaughton, V; Cutini, S; de Palma, F; Dingus, B L; Silva, E do Couto e; Fishman, G; Galli, A; Gehrels, N; Giglietto, N; Granot, J; Guiriec, S; Hughes, R E; Kamae, T; Komin, N; Kühn, F; Kuss, M; Longo, F; Lubrano, P; Kippen, R M; Mazziotta, M N; McEnery, J E; McGlynn, S; Moretti, E; Nakamori, T; Norris, J P; Ohno, M; Olivo, M; Omodei, N; Pelassa, V; Piron, F; Preece, R; Razzano, M; Russell, J J; Ryde, F; Parkinson, P M Saz; Scargle, J D; Sgrň, C; Shimokawabe, T; Smith, P D; Spandre, G; Spinelli, P; Stamatikos, M; Winer, B L; Yamazaki, R

2009-01-01T23:59:59.000Z

19

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mail ShareRed CrossAn Iridate with Fermi Arcs An Iridate

20

High-Tc superconductivity in entirely end-bonded multi-walled carbon nanotubes  

E-Print Network [OSTI]

We report that entirely end-bonded multi-walled carbon nanotubes (MWNTs) can show superconductivity with the transition temperature Tc as high as 12K that is approximately 40-times larger than those reported in ropes of single-walled nanotubes. We find that emergence of this superconductivity is very sensitive to junction structures of Au electrode/MWNTs. This reveals that only MWNTs with optimal numbers of electrically activated shells, which are realized by the end-bonding, can allow the superconductivity due to inter shell effects.

I. Takesue; J. Haruyama; N. Kobayashi; S. Chiashi; S. Maruyama; T. Sugai; H. Shinohara

2005-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

atomic fermi gas: Topics by E-print Network  

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

atomic Fermi gases. G. M. Bruun 2002-10-29 4 Fermi excitations in a trapped atomic Fermi gas with a molecular Bose condensate Condensed Matter (arXiv) Summary: We discuss the...

22

Generalized charge-screening in relativistic Thomas–Fermi model  

SciTech Connect (OSTI)

In this paper, we study the charge shielding within the relativistic Thomas-Fermi model for a wide range of electron number-densities and the atomic-number of screened ions. A generalized energy-density relation is obtained using the force-balance equation and taking into account the Chandrasekhar's relativistic electron degeneracy pressure. By numerically solving a second-order nonlinear differential equation, the Thomas-Fermi screening length is investigated, and the results are compared for three distinct regimes of the solid-density, warm-dense-matter, and white-dwarfs (WDs). It is revealed that our nonlinear screening theory is compatible with the exponentially decaying Thomas-Fermi-type shielding predicted by the linear response theory. Moreover, the variation of relative Thomas-Fermi screening length shows that extremely dense quantum electron fluids are relatively poor charge shielders. Calculation of the total number of screening electrons around a nucleus shows that there is a position of maximum number of screening localized electrons around the screened nucleus, which moves closer to the point-like nucleus by increase in the plasma number density but is unaffected due to increase in the atomic-number value. It is discovered that the total number of screening electrons, (N{sub s}?r{sub TF}{sup 3}/r{sub d}{sup 3} where r{sub TF} and r{sub d} are the Thomas-Fermi and interparticle distance, respectively) has a distinct limit for extremely dense plasmas such as WD-cores and neutron star crusts, which is unique for all given values of the atomic-number. This is equal to saying that in an ultrarelativistic degeneracy limit of electron-ion plasma, the screening length couples with the system dimensionality and the plasma becomes spherically self-similar. Current analysis can provide useful information on the effects of relativistic correction to the charge screening for a wide range of plasma density, such as the inertial-confined plasmas and compact stellar objects.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)

2014-10-15T23:59:59.000Z

23

Expansion of a Fermi gas interacting with a Bose-Einstein condensate  

E-Print Network [OSTI]

We study the expansion of an atomic Fermi gas interacting attractively with a Bose-Einstein condensate. We find that the interspecies interaction affects dramatically both the expansion of the Fermi gas and the spatial distribution of the cloud in trap. We observe indeed a slower evolution of the radial-to-axial aspect ratio which reveals the importance of the mutual attraction between the two samples during the first phase of the expansion. For large atom numbers, we also observe a bimodal momentum distribution of the Fermi gas, which reflects directly the distribution of the mixture in trap. This effect allows us to extract information on the dynamics of the system at the collapse.

F. Ferlaino; E. de Mirandes; G. Roati; G. Modugno; M. Inguscio

2003-12-10T23:59:59.000Z

24

Continuous transitions between composite Fermi liquid and Landau Fermi liquid: A route to fractionalized Mott insulators  

E-Print Network [OSTI]

One of the most successful theories of a non-Fermi-liquid metallic state is the composite Fermi-liquid (CFL) theory of the half-filled Landau level. In this paper, we study continuous quantum phase transitions out of the ...

Barkeshli, Maissam

25

Study of microwave/gamma-ray properties for Fermi-LAT bright AGNs  

E-Print Network [OSTI]

Blazars are a small fraction of all extragalactic sources but, unlike other objects, they are strong emitters across the entire electromagnetic spectrum. Recent data in the microwave region of the electromagnetic spectrum have become available to allow for systematic studies of blazars over large cosmological volumes. This frequency band is indeed particularly suited for the selection of blazars since at these frequencies the contamination from radio extended components with steep spectra is no longer present and the emission from the accretion process is negligible. During the first 3 months of scientific operations Fermi-LAT detected 106 bright, high-galactic latitude (| b |> 10 deg) AGNs with high significance. In this study we investigate the possible relations between the microwave and the gamma-ray emissions for Fermi-LAT detected AGNs belonging to WMAP 5th year bright source catalog.

Gasparrini, D; Giommi, P; Pittori, C; Colafrancesco, S

2009-01-01T23:59:59.000Z

26

Soliton trains in Bose-Fermi mixtures  

E-Print Network [OSTI]

We theoretically consider the formation of bright solitons in a mixture of Bose and Fermi degenerate gases. While we assume the forces between atoms in a pure Bose component to be effectively repulsive, their character can be changed from repulsive to attractive in the presence of fermions provided the Bose and Fermi gases attract each other strongly enough. In such a regime the Bose component becomes a gas of effectively attractive atoms. Hence, generating bright solitons in the bosonic gas is possible. Indeed, after a sudden increase of the strength of attraction between bosons and fermions (realized by using a Feshbach resonance technique or by firm radial squeezing of both samples) soliton trains appear in the Bose-Fermi mixture.

T. Karpiuk; M. Brewczyk; S. Ospelkaus-Schwarzer; K. Bongs; M. Gajda; K. Rzazewski

2004-04-14T23:59:59.000Z

27

2013 Annual Planning Summary for the FERMI Site Office  

Broader source: Energy.gov [DOE]

The ongoing and projected Environmental Assessments and Environmental Impact Statements for 2013 and 2014 within the FERMI Site Office.

28

Theory of ultracold atomic Fermi gases  

SciTech Connect (OSTI)

The physics of quantum degenerate atomic Fermi gases in uniform as well as in harmonically trapped configurations is reviewed from a theoretical perspective. Emphasis is given to the effect of interactions that play a crucial role, bringing the gas into a superfluid phase at low temperature. In these dilute systems, interactions are characterized by a single parameter, the s-wave scattering length, whose value can be tuned using an external magnetic field near a broad Feshbach resonance. The BCS limit of ordinary Fermi superfluidity, the Bose-Einstein condensation (BEC) of dimers, and the unitary limit of large scattering length are important regimes exhibited by interacting Fermi gases. In particular, the BEC and the unitary regimes are characterized by a high value of the superfluid critical temperature, on the order of the Fermi temperature. Different physical properties are discussed, including the density profiles and the energy of the ground-state configurations, the momentum distribution, the fraction of condensed pairs, collective oscillations and pair-breaking effects, the expansion of the gas, the main thermodynamic properties, the behavior in the presence of optical lattices, and the signatures of superfluidity, such as the existence of quantized vortices, the quenching of the moment of inertia, and the consequences of spin polarization. Various theoretical approaches are considered, ranging from the mean-field description of the BCS-BEC crossover to nonperturbative methods based on quantum Monte Carlo techniques. A major goal of the review is to compare theoretical predictions with available experimental results.

Giorgini, Stefano; Pitaevskii, Lev P.; Stringari, Sandro [Dipartimento di Fisica, Universita di Trento and CNR-INFM BEC Center, I-38050 Povo, Trento (Italy); Dipartimento di Fisica, Universita di Trento and CNR-INFM BEC Center, I-38050 Povo, Trento, Italy and Kapitza Institute for Physical Problems, ul. Kosygina 2, 117334 Moscow (Russian Federation); Dipartimento di Fisica, Universita di Trento and CNR-INFM BEC Center, I-38050 Povo, Trento (Italy)

2008-10-15T23:59:59.000Z

29

Genuine tripartite entanglement in the non-interacting Fermi gas  

E-Print Network [OSTI]

We study genuine tripartite entanglement shared among the spins of three localized fermions in the non-interacting Fermi gas at zero temperature. Firstly, we prove analytically with the aid of entanglement witnesses that in a particular configuration the three fermions are genuinely tripartite entangled. Then various three-fermion configurations are investigated in order to quantify and calculate numerically the amount of genuine tripartite entanglement present in the system. Further we give a lower and an upper limit to the maximum diameter of the three-fermion configuration below which genuine tripartite entanglement exists and find that this distance is comparable with the maximum separation between two entangled fermions. The upper and lower limit turn to be very close to each other indicating that the applied witness operator is well suited to reveal genuine tripartite entanglement in the collection of non-interacting fermions.

T. Vértesi

2007-01-31T23:59:59.000Z

30

FermiGrid - experience and future plans  

SciTech Connect (OSTI)

Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid and the WLCG. FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the Open Science Grid (OSG), EGEE and the Worldwide LHC Computing Grid Collaboration (WLCG). Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure--the successes and the problems.

Chadwick, K.; Berman, E.; Canal, P.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Timm, S.; Yocum, D.; /Fermilab

2007-09-01T23:59:59.000Z

31

Comments on Fermi Liquid from Holography  

E-Print Network [OSTI]

We investigate the signatures of Fermi liquid formation in the N=4 super Yang-Mills theory coupled to fundamental hypermultiplet at nonvanishing chemical potential for the global U(1) vector symmetry. At strong 't Hooft coupling the system can be analyzed in terms of the D7 brane dynamics in AdS_5 x S^5 background. The phases with vanishing and finite charge density are separated at zero temperature by a quantum phase transition. In case of vanishing hypermultiplet mass, Karch, Son and Starinets discovered a gapless excitation whose speed equals the speed of sound. We find that this zero sound mode persists to all values of the hypermultiplet mass, and its speed vanishes at the point of phase transition. The value of critical exponent and the ratio of the velocities of zero and first sounds are consistent with the predictions of Landau Fermi liquid theory at strong coupling.

Manuela Kulaxizi; Andrei Parnachev

2008-10-13T23:59:59.000Z

32

Comments on Fermi Liquid from Holography  

E-Print Network [OSTI]

We investigate the signatures of Fermi liquid formation in the N=4 super Yang-Mills theory coupled to fundamental hypermultiplet at nonvanishing chemical potential for the global U(1) vector symmetry. At strong 't Hooft coupling the system can be analyzed in terms of the D7 brane dynamics in AdS_5 x S^5 background. The phases with vanishing and finite charge density are separated at zero temperature by a quantum phase transition. In case of vanishing hypermultiplet mass, Karch, Son and Starinets discovered a gapless excitation whose speed equals the speed of sound. We find that this zero sound mode persists to all values of the hypermultiplet mass, and its speed vanishes at the point of phase transition. The value of critical exponent and the ratio of the velocities of zero and first sounds are consistent with the predictions of Landau Fermi liquid theory at strong coupling.

Kulaxizi, Manuela

2008-01-01T23:59:59.000Z

33

Nuclear response beyond the Fermi gas model  

E-Print Network [OSTI]

The Fermi gas model, while providing a reasonable qualitative description of the continuum nuclear response, does not include the effects of dynamical nucleon-nucleon correlations in the initial and final states, that have long been recognized to play a critical role in specific kinematical regions. We review a many-body approach in which these effects are consistently taken into account and discuss the results of a calculation of the quasielastic neutrino-oxygen cross section as an illustrative example.

Omar Benhar

2003-07-14T23:59:59.000Z

34

The free states-related Fermi pocket of cuprate superconductors  

E-Print Network [OSTI]

To stress the effect of the pairing position deviating from the Fermi level, we must investigate the pairs in the wave vector space, and then we use the dynamic equation to study some correlation functions. This article shows that the Fermi pocket is related to the effect of free electron states on the ARPES experiment. This also leads us to understand why the Fermi arc appears in Bi2212 while the Fermi pocket appears in Bi2201 with the valence bandwidth and the work function known for them.

Tian De Cao

2010-07-13T23:59:59.000Z

35

Local Fermi gas in inclusive muon capture from nuclei  

E-Print Network [OSTI]

We compare local Fermi gas and shell model in muon capture in nuclei in order to estimate the effect of finite nuclear size in low energy weak reactions.

J. E. Amaro; J. Nieves; M. Valverde; C. Maieron

2006-05-20T23:59:59.000Z

36

Investigation of the deformed fermi surfaces  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 viii LIST OF FIGURES FIGURE Page 1 Gap of Sarma?s solution III with N(0)V=0.3, ?T = 1k BT = 1000/?BCS 6 2 Energy ofSarma?s solution III with N(0)V=0.3, ?T = 1k BT = 1000/?BCS 6 3 A rough picture of fermi surfaces of FF states... relative to the chemical potential ??. This Hamiltonian reduces to the corresponding one in 4 the BCS theory if h ? ?BH is set to zero. As in the BCS theory, which is for an s-wave superconductor, Sarma assumed: Vkk? = ? ?? ?? V if |?k| < planckover2pi1?D...

Lu, Jianxu

2009-05-15T23:59:59.000Z

37

Fermi LAT Observations of LS 5039  

SciTech Connect (OSTI)

The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent with the binary period, with the emission being modulated with a period of 3.903 {+-} 0.005 days; the first detection of this modulation at GeV energies. The light curve is characterized by a broad peak around superior conjunction in agreement with inverse Compton scattering models. The spectrum is represented by a power law with an exponential cutoff, yielding an overall flux (100 MeV-300 GeV) of 4.9 {+-} 0.5(stat) {+-} 1.8(syst) x 10{sup -7} photon cm{sup -2} s{sup -1}, with a cutoff at 2.1 {+-} 0.3(stat) {+-} 1.1(syst) GeV and photon index {Gamma} = 1.9 {+-} 0.1(stat) {+-} 0.3(syst). The spectrum is observed to vary with orbital phase, specifically between inferior and superior conjunction. We suggest that the presence of a cutoff in the spectrum may be indicative of magnetospheric emission similar to the emission seen in many pulsars by Fermi.

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Washington U., Seattle /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /DAPNIA, Saclay /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U. /Stockholm U., OKC /DAPNIA, Saclay /NASA, Goddard /CSST, Baltimore /SLAC /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC /Grenoble Observ. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U.; /more authors..

2012-03-29T23:59:59.000Z

38

ABJM theory as a Fermi gas  

E-Print Network [OSTI]

The partition function on the three-sphere of many supersymmetric Chern-Simons-matter theories reduces, by localization, to a matrix model. We develop a new method to study these models in the M-theory limit, but at all orders in the 1/N expansion. The method is based on reformulating the matrix model as the partition function of an ideal Fermi gas with a non-trivial, one-particle quantum Hamiltonian. This new approach leads to a completely elementary derivation of the N^{3/2} behavior for ABJM theory and N=3 quiver Chern-Simons-matter theories. In addition, the full series of 1/N corrections to the original matrix integral can be simply determined by a next-to-leading calculation in the WKB or semiclassical expansion of the quantum gas, and we show that, for several quiver Chern-Simons-matter theories, it is given by an Airy function. This generalizes a recent result of Fuji, Hirano and Moriyama for ABJM theory. It turns out that the semiclassical expansion of the Fermi gas corresponds to a strong coupling expansion in type IIA theory, and it is dual to the genus expansion. This allows us to calculate explicitly non-perturbative effects due to D2-brane instantons in the AdS background.

Marcos Marino; Pavel Putrov

2012-03-14T23:59:59.000Z

39

Fermi Large Area Telescope Third Source Catalog  

E-Print Network [OSTI]

We present the third Fermi Large Area Telescope source catalog (3FGL) of sources in the 100~MeV--300~GeV range. Based on the first four years of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the 2FGL catalog, the 3FGL catalog incorporates twice as much data as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources above 4 sigma significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 232 sources are considered as identifie...

,

2015-01-01T23:59:59.000Z

40

Dust acoustic solitary and shock excitations in a Thomas-Fermi magnetoplasma  

SciTech Connect (OSTI)

The linear and nonlinear properties of dust-acoustic waves are investigated in a collisionless Thomas-Fermi magnetoplasma, whose constituents are electrons, ions, and negatively charged dust particles. At dust time scale, the electron and ion number densities follow the Thomas-Fermi distribution, whereas the dust component is described by the classical fluid equations. A linear dispersion relation is analyzed to show that the wave frequencies associated with the upper and lower modes are enhanced with the variation of dust concentration. The effect of the latter is seen more strongly on the upper mode as compared to the lower mode. For nonlinear analysis, we obtain magnetized Korteweg-de Vries (KdV) and Zakharov-Kuznetsov (ZK) equations involving the dust-acoustic solitary waves in the framework of reductive perturbation technique. Furthermore, the shock wave excitations are also studied by allowing dissipation effects in the model, leading to the Korteweg-de Vries-Burgers (KdVB) and ZKB equations. The analysis reveals that the dust-acoustic solitary and shock excitations in a Thomas-Fermi plasma are strongly influenced by the plasma parameters, e.g., dust concentration, dust temperature, obliqueness, magnetic field strength, and dust fluid viscosity. The present results should be important for understanding the solitary and shock excitations in the environments of white dwarfs or supernova, where dust particles can exist.

Rahim, Z.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)

2014-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

The first full orbit of Eta Carinae seen by Fermi  

E-Print Network [OSTI]

The binary system eta Carinae has completed its first 5.54y orbit since the beginning of science operation of the Fermi Large Area Telescope (LAT). We are now able to investigate the high-energy gamma-ray source at the position of eta Carinae over its full orbital period. By this, we can address and confirm earlier predictions for temporal and spectral variability. Newer versions of the LAT datasets, instrument response functions and background models allow for a more accurate analysis. Therefore it is important to re-evaluate the previously analyzed time period along with the new data to further constrain location, spectral shape, and flux time history of the gamma-ray source. We confirm earlier predictions of increasing flux values above 10 GeV toward the next periastron passage. For the most recent part of the data sample, flux values as high as those before the first periastron passage in 2008 are recorded. A comparison of spectral energy distributions around periastron and apastron passages reveals stron...

Reitberger, K; Reimer, O; Takahashi, H

2015-01-01T23:59:59.000Z

42

Momentum sharing in imbalanced Fermi systems  

E-Print Network [OSTI]

The atomic nucleus is composed of two different kinds of fermions, protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe and 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few body systems to neutron stars and may also be observable experimentally in two-spin state, ultra-cold atomic gas systems.

O. Hen; M. Sargsian; L. B. Weinstein; E. Piasetzky; H. Hakobyan; D. W. Higinbotham; M. Braverman; W. K. Brooks; S. Gilad; K. P. Adhikari; J. Arrington; G. Asryan; H. Avakian; J. Ball; N. A. Baltzell; M. Battaglieri; A. Beck; S. May-Tal Beck; I. Bedlinskiy; W. Bertozzi; A. Biselli; V. D. Burkert; T. Cao; D. S. Carman; A. Celentano; S. Chandavar; L. Colaneri; P. L. Cole; V. Crede; A. DAngelo; R. De Vita; A. Deur; C. Djalali; D. Doughty; M. Dugger; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; G. Fedotov; S. Fegan; T. Forest; B. Garillon; M. Garcon; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; F. X. Girod; J. T. Goetz; R. W. Gothe; K. A. Griffioen; M. Guidal; L. Guo; K. Hafidi; C. Hanretty; M. Hattawy; K. Hicks; M. Holtrop; C. E. Hyde; Y. Ilieva; D. G. Ireland; B. I. Ishkanov; E. L. Isupov; H. Jiang; H. S. Jo; K. Joo; D. Keller; M. Khandaker; A. Kim; W. Kim; F. J. Klein; S. Koirala; I. Korover; S. E. Kuhn; V. Kubarovsky; P. Lenisa; W. I. Levine; K. Livingston; M. Lowry; H. Y. Lu; I. J. D. MacGregor; N. Markov; M. Mayer; B. McKinnon; T. Mineeva; V. Mokeev; A. Movsisyan; C. Munoz Camacho; B. Mustapha; P. Nadel-Turonski; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; L. L. Pappalardo; R. Paremuzyan; K. Park; E. Pasyuk; W. Phelps; S. Pisano; O. Pogorelko; J. W. Price; S. Procureur; Y. Prok; D. Protopopescu; A. J. R. Puckett; D. Rimal; M. Ripani; B. G. Ritchie; A. Rizzo; G. Rosner; P. Rossi; P. Roy; F. Sabatie; D. Schott; R. A. Schumacher; Y. G. Sharabian; G. D. Smith; R. Shneor; D. Sokhan; S. S. Stepanyan; S. Stepanyan; P. Stoler; S. Strauch; V. Sytnik; M. Taiuti; S. Tkachenko; M. Ungaro; A. V. Vlassov; E. Voutier; D. Watts; N. K. Walford; X. Wei; M. H. Wood; S. A. Wood; N. Zachariou; L. Zana; Z. W. Zhao; X. Zheng; I. Zonta

2014-11-29T23:59:59.000Z

43

Momentum sharing in imbalanced Fermi systems  

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

The atomic nucleus is composed of two different kinds of fermions, protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe and 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few body systems to neutron stars and may also be observable experimentally in two-spin state, ultra-cold atomic gas systems.q

Hen, O.; Sargsian, M.; Weinstein, L. B.; Piasetzky, E.; Hakobyan, H.; Higinbotham, D. W.; Braverman, M.; Brooks, W. K.; Gilad, S.; Adhikari, K. P.; Arrington, J.; Asryan, G.; Avakian, H.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Beck, A.; Beck, S M -T; Bedlinskiy, I.; Bertozzi, W.; Biselli, A.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Colaneri, L.; Cole, P. L.; Crede, V.; D'Angelo, A.; De Vita, R.; Deur, A.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Fedotov, G.; Fegan, S.; Forest, T.; Garillon, B.; Garcon, M.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Girod, F. X.; Goetz, J. T.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkanov, B. I.; Isupov, E. L.; Jiang, H.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Koirala, S.; Korover, I.; Kuhn, S. E.; Kubarovsky, V.; Lenisa, P.; Levine, W. I.; Livingston, K.; Lowry, M.; Lu, H. Y.; MacGregor, I. J.; Markov, N.; Mayer, M.; McKinnon, B.; Mineeva, T.; Mokeev, V.; Movsisyan, A.; Camacho, C. M.; Mustapha, B.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Phelps, W.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rizzo, A.; Rosner, G.; Roy, P.; Rossi, P.; Sabatie, F.; Schott, D.; Schumacher, R. A.; Sharabian, Y. G.; Smith, G. D.; Shneor, R.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tkachenko, S.; Ungaro, M.; Vlassov, A. V.; Voutier, E.; Walford, N. K.; Wei, X.; Wood, M. H.; Wood, S. A.; Zachariou, N.; Zana, L.; Zhao, Z. W.; Zheng, X.; Zonta, I.

2014-10-30T23:59:59.000Z

44

Calculating correlated color temperatures across the entire gamut of daylight and skylight chromaticities  

E-Print Network [OSTI]

Calculating correlated color temperatures across the entire gamut of daylight and skylight daylight and skylight spectra to test an equation that accurately maps CIE 1931 chromaticities x and y by daylight and skylight. © 1999 Optical Society of America OCIS codes: 010.1290, 330.1710, 330.1730. 1

Lee Jr., Raymond L.

45

OPTIMIZATION WITH ENERGY MANAGEMENT OF PV BATTERY STAND-ALONE SYSTEMS OVER THE ENTIRE LIFE CYCLE  

E-Print Network [OSTI]

of both the installed PV power and storage capacity (lead-acid battery technology for purposes). Keywords: Battery storage and control, Lifetime simulation, PV system. 1. INTRODUCTION Given the sizableOPTIMIZATION WITH ENERGY MANAGEMENT OF PV BATTERY STAND-ALONE SYSTEMS OVER THE ENTIRE LIFE CYCLE

Paris-Sud XI, Université de

46

Entirely passive heat-pipe apparatus capable of operating against gravity  

DOE Patents [OSTI]

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, D.R.

1981-02-11T23:59:59.000Z

47

Fermi-surface reconstruction and the origin of high-temperature superconductivity.  

SciTech Connect (OSTI)

In crystalline lattices, the conduction electrons form waves, known as Bloch states, characterized by a momentum vector k. The defining characteristic of metals is the surface in momentum space that separates occupied from unoccupied states. This 'Fermi' surface may seem like an abstract concept, but it can be measured and its shape can have profound consequences for the thermal, electronic, and magnetic properties of a material. In the presence of an external magnetic field B, electrons in a metal spiral around the field direction, and within a semiclassical momentum-space picture, orbit around the Fermi surface. Physical properties, such as the magnetization, involve a sum over these orbits, with extremal orbits on the Fermi surface, i.e., orbits with minimal or maximal area, dominating the sum [Fig. 1(a)]. Upon quantization, the resulting electron energy spectrum consists of Landau levels separated by the cyclotron energy, which is proportional to the magnetic field. As the magnetic field causes subsequent Landau levels to cross through the Fermi energy, physical quantities, such as the magnetization or resistivity, oscillate in response. It turns out that the period of these oscillations, when plotted as a function of 1/B, is proportional to the area of the extremal orbit in a plane perpendicular to the applied field [Fig. 1(b)]. The power of the quantum oscillation technique is obvious: By changing the field direction, one can map out the Fermi surface, much like a blind man feeling an elephant. The nature and topology of the Fermi surface in high-T{sub c} cuprates has been debated for many years. Soon after the materials were discovered by Bednorz and Mueller, it was realized that superconductivity was obtained by doping carriers into a parent insulating state. This insulating state appears to be due to strong electronic correlations, and is known as a Mott insulator. In the case of cuprates, the electronic interactions force the electrons on the copper ion lattice into a d{sup 9} configuration, with one localized hole in the 3d shell per copper site. Given the localized nature of this state, it was questioned whether a momentum-space picture was an appropriate description of the physics of the cuprates. In fact, this question relates to a long-standing debate in the physics community: Since the parent state is also an antiferromagnet, one can, in principle, map the Mott insulator to a band insulator with magnetic order. In this 'Slater' picture, Mott physics is less relevant than the magnetism itself. It is therefore unclear which of the two, magnetism or Mott physics, is more fundamentally tied to superconductivity in the cuprates. After twenty years of effort, definitive quantum oscillations that could be used to map the Fermi surface were finally observed in a high-temperature cuprate superconductor in 2007. This and subsequent studies reveal a profound rearrangement of the Fermi surface in underdoped cuprates. The cause of the reconstruction, and its implication for the origin of high-temperature superconductivity, is a subject of active debate.

Norman, M. R.; Materials Science Division

2010-01-01T23:59:59.000Z

48

Sobre a viagem de Enrico Fermi ao Brasil em 1934  

E-Print Network [OSTI]

Enrico Fermi was one of the greater physicists of the XX century. In 1934, he gave several lectures in Brazil. Invited by Theodoro Ramos to work in S\\~ao Paulo, he preferred to stay in Rome and went to the USA in 1938. However, Fermi recommended Gleb Wataghin to come in his place. Wataghin made history in Brazil, becoming one of the first Professors of the future S\\~ao Paulo University. Besides his relevance to the History of Science, Fermi eventually leaved an indelible mark on the creation and institutionalization of national scientific research due to the indication of Wataghin. Despite this fact, very little is known about Fermi's trip to Brazil. This work tries to reconstruct the fullest possible steps of the famous Italian physicist in our lands.

Caruso, Francisco

2014-01-01T23:59:59.000Z

49

On the construction of Fermi-Walker transported frames  

E-Print Network [OSTI]

We consider tetrad fields as reference frames adapted to observers that move along arbitrary timelike trajectories in spacetime. By means of a local Lorentz transformation we can transform these frames into Fermi-Walker transported frames, which define a standard of non-rotation for accelerated observers. Here we present a simple prescription for the construction of Fermi-Walker transported frames out of an arbitrary set of tetrad fields.

J. W. Maluf; F. F. Faria

2008-04-15T23:59:59.000Z

50

First Ever STEREO Images of the Entire Sun These presentations give additional information on how STEREO's first ever  

E-Print Network [OSTI]

STEREO 360 1 First Ever STEREO Images of the Entire Sun These presentations give additional information on how STEREO's first ever views of the entire sun will advance the study of solar and space years the STEREO spacecrafts and SDO will be able to observe the entire 360 degrees of the Sun. Credit

Christian, Eric

51

Fermi/LAT broad emission line blazars  

E-Print Network [OSTI]

We study the broad emission line blazars detected in the gamma-ray band by the Large Area Telescope onboard the Fermi satellite and with the optical spectrum studied by Shaw et al. (2012, 2013). The observed broad line strength provides a measure of the ionizing luminosity of the accretion disk, while the gamma-luminosity is a proxy for the bolometric non-thermal beamed jet emission. The resulting sample, composed by 217 blazars, is the best suited to study the connection between accretion and jet properties. We compare the broad emission line properties of these blazars with those of radio-quiet and radio-loud quasars present in the Sloan Digital Sky Survey, to asses differences and similarities of the disc luminosity and the virial black hole mass. For most sources, we could derive the black hole mass by reproducing the IR-optical-UV data with a standard accretion disc spectrum, and we compared the black hole masses derived with the two methods. The distributions of the masses estimated in the two ways agre...

Ghisellini, G

2015-01-01T23:59:59.000Z

52

ENERGETIC FERMI/LAT GRB 100414A: ENERGETIC AND CORRELATIONS  

SciTech Connect (OSTI)

This study presents multi-wavelength observational results for energetic GRB 100414A with GeV photons. The prompt spectral fitting using Suzaku/WAM data yielded spectral peak energies of E{sup src}{sub peak} of 1458.7{sup +132.6}{sub -106.6} keV and E{sub iso} of 34.5{sup +2.0}{sub -1.8} Multiplication-Sign 10{sup 52} erg with z = 1.368. The optical afterglow light curves between 3 and 7 days were effectively fitted according to a simple power law with a temporal index of {alpha} = -2.6 {+-} 0.1. The joint light curve with earlier Swift/UVOT observations yields a temporal break at 2.3 {+-} 0.2 days. This was the first Fermi/LAT detected event that demonstrated the clear temporal break in the optical afterglow. The jet opening angle derived from this temporal break was 5.{sup 0}8, consistent with those of other well-observed long gamma-ray bursts (GRBs). The multi-wavelength analyses in this study showed that GRB 100414A follows E{sup src}{sub peak}-E{sub iso} and E{sup src}{sub peak}-E{sub {gamma}} correlations. The late afterglow revealed a flatter evolution with significant excesses at 27.2 days. The most straightforward explanation for the excess is that GRB 100414A was accompanied by a contemporaneous supernova. The model light curve based on other GRB-SN events is marginally consistent with that of the observed light curve.

Urata, Yuji; Tsai, Patrick P. [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Huang, Kuiyun [Academia Sinica Institute of Astronomy and Astrophysics, Taipei 106, Taiwan (China); Yamaoka, Kazutaka [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1, Fuchinobe, Sayamihara 229-8558 (Japan); Tashiro, Makoto S., E-mail: urata@astro.ncu.edu.tw [Department of Physics, Saitama University, Shimo-Okubo, Saitama 338-8570 (Japan)

2012-03-20T23:59:59.000Z

53

Emission vs Fermi coordinates: applications to relativistic positioning systems  

E-Print Network [OSTI]

A 4-dimensional relativistic positioning system for a general spacetime is constructed by using the so called "emission coordinates". The results apply in a small region around the world line of an accelerated observer carrying a Fermi triad, as described by the Fermi metric. In the case of a Schwarzschild spacetime modeling the gravitational field around the Earth and an observer at rest at a fixed spacetime point, these coordinates realize a relativistic positioning system alternative to the current GPS system. The latter is indeed essentially conceived as Newtonian, so that it necessarily needs taking into account at least the most important relativistic effects through Post-Newtonian corrections to work properly. Previous results concerning emission coordinates in flat spacetime are thus extended to this more general situation. Furthermore, the mapping between spacetime coordinates and emission coordinates is completely determined by means of the world function, which in the case of a Fermi metric can be explicitly obtained.

Donato Bini; Andrea Geralico; Matteo Luca Ruggiero; Angelo Tartaglia

2008-09-05T23:59:59.000Z

54

Exponential Fermi acceleration in general time-dependent billiards  

E-Print Network [OSTI]

It is shown, that under very general conditions, a generic time-dependent billiard, for which a phase-space of corresponding static (frozen) billiards is of the mixed type, exhibits the exponential Fermi acceleration in the adiabatic limit. The velocity dynamics in the adiabatic regime is represented as an integral over a path through the abstract space of invariant components of corresponding static billiards, where the paths are generated probabilistically in terms of transition-probability matrices. We study the statistical properties of possible paths and deduce the conditions for the exponential Fermi acceleration. The exponential Fermi acceleration and theoretical concepts presented in the paper are demonstrated numerically in four different time-dependent billiards.

Benjamin Batisti?

2014-04-07T23:59:59.000Z

55

Emergent Fermi surfaces, fractionalization and duality in supersymmetric QED  

E-Print Network [OSTI]

We study the physics of 3d supersymmetric abelian gauge theories (with small supersymmetry breaking perturbations) at finite density. Using mirror symmetry, which provides a natural generalization of the duality between the XY model and the abelian Higgs model but now including fermionic fields, we see many dynamical phenomena conjectured to be of relevance in condensed matter systems. In particular, we find examples of the emergence of a Fermi surface at low energies from hybridization of fermions localized at magnetic defects at high energies, as well as fractionalization of charged fermions into spinon-holon pairs with the concomitant appearance of emergent gauge fields. We also find dual descriptions for Fermi surfaces coupled to critical bosons, which give rise to non-Fermi liquids.

Anson Hook; Shamit Kachru; Gonzalo Torroba; Huajia Wang

2014-07-13T23:59:59.000Z

56

Gamma-Ray Emission in Dissipative Pulsar Magnetospheres: From Theory to Fermi Observations  

E-Print Network [OSTI]

We compute the patterns of $\\gamma$-ray emission due to curvature radiation in dissipative pulsar magnetospheres. Our ultimate goal is to construct macrophysical models that are able to reproduce the observed $\\gamma$-ray light-curve phenomenology recently published in the Second Fermi Pulsar Catalog. We apply specific forms of Ohm's law on the open field lines using a broad range for the macroscopic conductivity values that result in solutions ranging, from near-vacuum to near Force-Free. Using these solutions, we generate model $\\gamma$-ray light curves by calculating realistic trajectories and Lorentz factors of radiating particles, under the influence of both the accelerating electric fields and curvature radiation-reaction. We further constrain our models using the observed dependence of the phase-lags between the radio and $\\gamma$-ray emission on the $\\gamma$-ray peak-separation. We perform a statistical comparison of our model radio-lag vs peak-separation diagram and the one obtained for the Fermi standard pulsars. We find that for models of uniform conductivity over the entire open magnetic field line region, agreement with observations favors higher values of this parameter. We find, however, significant improvement in fitting the data with models that employ a hybrid form of conductivity; specifically, infinite conductivity interior to the light-cylinder and high but finite conductivity on the outside. In these models the $\\gamma$-ray emission is produced in regions near the equatorial current sheet but modulated by the local physical properties. These models have radio-lags near the observed values and statistically best reproduce the observed light-curve phenomenology. Additionally, these models produce GeV photon cut-off energies.

Constantinos Kalapotharakos; Alice K. Harding; Demosthenes Kazanas

2014-07-27T23:59:59.000Z

57

The Spectral Energy Distribution of Fermi bright blazars  

E-Print Network [OSTI]

(Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \\gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous Spectral Energy Distributions (SED) for 48 LBAS blazars.The SED of these gamma-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual Log $\

Abdo, A A; Ajello, M; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chaty, S; Chekhtman, A; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Colafrancesco, S; Cominsky, L R; Conrad, J; Costamante, L; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Silva, E do Couto e; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fuhrmann, L; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guillemot, L; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Healey, S E; Horan, D; Hughes, R E; Itoh, R; Jackson, M S; Johannesson, G; Johnson, A S; Johnson, W N; Kadler, M; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knodlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Max-Moerbeck, W; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F

2009-01-01T23:59:59.000Z

58

Fermi velocity renormalization and dynamical gap generation in graphene  

E-Print Network [OSTI]

We study the renormalization of the Fermi velocity by the long-range Coulomb interactions between the charge carriers in the Dirac-cone approximation for the effective low-energy description of the electronic excitations in graphene at half filling. Solving the coupled system of Dyson-Schwinger equations for the dressing functions in the corresponding fermion propagator with various approximations for the particle-hole polarization we observe that Fermi velocity renormalization effects generally lead to a considerable increase of the critical coupling for dynamical gap generation and charge-density wave formation at the semimetal-insulator transition.

C. Popovici; C. S. Fischer; L. von Smekal

2015-01-12T23:59:59.000Z

59

Gamma-ray Spectral Evolution of NGC1275 Observed with Fermi-LAT  

E-Print Network [OSTI]

We report on a detailed investigation of the high-energy gamma-ray emission from NGC\\,1275, a well-known radio galaxy hosted by a giant elliptical located at the center of the nearby Perseus cluster. With the increased photon statistics, the center of the gamma-ray emitting region is now measured to be separated by only 0.46' from the nucleus of NGC1275, well within the 95% confidence error circle with radius ~1.5'. Early Fermi-LAT observations revealed a significant decade-timescale brightening of NGC1275 at GeV photon energies, with a flux about seven times higher than the one implied by the upper limit from previous EGRET observations. With the accumulation of one-year of Fermi-LAT all-sky-survey exposure, we now detect flux and spectral variations of this source on month timescales, as reported in this paper. The average >100 MeV gamma-ray spectrum of NGC1275 shows a possible deviation from a simple power-law shape, indicating a spectral cut-off around an observed photon energy of E = 42.2+-19.6 GeV, with...

Kataoka, J; Cheung, C C; Tosti, G; Cavazzuti, E; Celotti, A; Nishino, S; Fukazawa, Y; Thompson, D J; McConville, W F

2010-01-01T23:59:59.000Z

60

POLARIZATION AND VARIATION OF NEAR-INFRARED LIGHT FROM FERMI/LAT {gamma}-RAY SOURCES  

SciTech Connect (OSTI)

We present the results of our follow-up observation program of {gamma}-ray sources detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. Twenty-six blazars and thirty-nine sources unidentified at other wavelengths were targeted at the Infrared Survey Facility 1.4 m telescope equipped with the SIRIUS/SIRPOL imager and polarimeter. H-band magnitudes of the blazars at the epoch of 2010 December-2011 February are presented, which reveal clear flux variation since the Two Micron All Sky Survey observations and can be useful data for variation analyses of these objects in longer periods. We also find that nearly half of the {gamma}-ray blazars are highly (>10%) polarized in near-infrared wavelengths. Combining the polarization and variation properties, most ({approx}90%) of the blazars are clearly distinguished from all other types of objects at high Galactic latitudes. On the other hand, we find only one highly polarized and/or variable object in the fields of unidentified sources. This object is a counterpart of the optical variable source PQV1 J131553.00-073302.0 and the radio source NVSS J131552-073301 and is a promising candidate of new {gamma}-ray blazars. From the measured polarization and variation statistics, we conclude that most of the Fermi/LAT unidentified sources are not likely similar types of objects to the known {gamma}-ray blazars.

Fujiwara, M.; Matsuoka, Y. [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Ienaka, N., E-mail: matsuoka@a.phys.nagoya-u.ac.jp [Institute of Astronomy, The University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015 (Japan)

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" from the National Library of EnergyBeta (NLEBeta).
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61

Investigation of collective radial expansion and stopping in heavy ion collisions at Fermi energies  

E-Print Network [OSTI]

Investigation of collective radial expansion and stopping in heavy ion collisions at Fermi energies in central Xe+Sn reactions at Fermi energies. Performing a comparison between the predictions central collisions at Fermi energies. However, considering the same central event selection

Boyer, Edmond

62

Uso del conocimiento de la arquitectura Fermi para mejorar el rendimiento en aplicaciones  

E-Print Network [OSTI]

Uso del conocimiento de la arquitectura Fermi para mejorar el rendimiento en aplicaciones CUDA Yuri arquitectura Fermi de NVIDIA introduce nuevos criterios a la hora de selec- cionar los tama~nos y la geometr arquitectura para aplicar adecua- damente t´ecnicas de optimizaci´on de c´odigo. Fermi [2] [3] [4] es la

Llanos, Diego R.

63

General Properties of Fermi/LAT Active Galactic Nuclei  

E-Print Network [OSTI]

The Second Catalog of Blazars and other Active Galactic Nuclei detected by the Fermi/LAT (2LAC) includes about 1100 sources, 886 of which comprise the Clean Sample. The general properties of the different populations of sources classified according to the strength of their emission lines (FSRQs, BL Lacs) or the estimated position of the synchrotron peak are reviewed.

Lott, B; Cutini, S; Gasparrini, D; Dermer, C D

2012-01-01T23:59:59.000Z

64

A method for Fermi energy measurements A. Tsukernik,a)  

E-Print Network [OSTI]

due to the built-in field, which converts the diffusive regime of transport into thermionic emission on the analysis of thermionic emission and diffusion over a barrier with a built-in charge. The method can cannot be employed for Fermi energy measurements. As a result, the temperature dependence of thermionic

Luryi, Serge

65

BCS-BEC Crossover and the Unitary Fermi Gas  

E-Print Network [OSTI]

The crossover from weak coupling Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) of tightly bound pairs, as a function of the attractive interaction in Fermi systems, has long been of interest to theoretical physicists. The past decade has seen a series of remarkable experimental developments in ultracold Fermi gases that has realized the BCS-BEC crossover in the laboratory, bringing with it fresh new insights into the very strongly interacting unitary regime in the middle of this crossover. In this review, we start with a pedagogical introduction to the crossover and then focus on recent progress in the strongly interacting regime. While our focus is on new theoretical developments, we also describe three key experiments that probe the thermodynamics, transport and spectroscopy of the unitary Fermi gas. We discuss connections between the unitary regime and other areas of physics -- quark-gluon plasmas, gauge-gravity duality and high temperature superconductivity -- and conclude with open questions about strongly interacting Fermi gases.

Mohit Randeria; Edward Taylor

2014-04-08T23:59:59.000Z

66

Gamma-ray Sky Observed with Fermi Large Area Telescope  

E-Print Network [OSTI]

detection reported Flare activity reported via ATel Gamma Ray Bursts reported via GCN Giant MC imageGamma-ray Sky Observed with Fermi Large Area Telescope RESCEU Symposium on Astroparticle Physics) Measure the photon direction Identification of the gamma-ray shower 36 planes of Si strip detectors (228 m

Yamamoto, Hirosuke

67

The role of Causality in Tunable Fermi Gas Condensates  

E-Print Network [OSTI]

We develop a new formalism for the description of the condensates of cold Fermi atoms whose speed of sound can be tuned with the aid of a narrow Feshbach resonance. We use this to look for spontaneous phonon creation that mimics spontaneous particle creation in curved space-time in Friedmann-Robertson-Walker and other model universes.

Jen-Tsung Hsiang; Chi-Yong Lin; Da-Shin Lee; Ray J. Rivers

2013-09-17T23:59:59.000Z

68

Nature of superfluidity in ultracold Fermi gases near Feshbach resonances  

SciTech Connect (OSTI)

We study the superfluid state of atomic Fermi gases using a BCS-Bose-Einstein-condensation crossover theory. Our approach emphasizes noncondensed fermion pairs which strongly hybridize with their (Feshbach-induced) molecular boson counterparts. These pairs lead to pseudogap effects above T{sub c} and non-BCS characteristics below. We discuss how these effects influence the experimental signatures of superfluidity.

Stajic, Jelena; Levin, K. [James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Milstein, J.N.; Holland, M.J. [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, Colorado 80309 (United States); Chen Qijin [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Chiofalo, M.L. [Classe di Scienze and INFM, Scuola Normale Superiore, Piazza dei Cavelieri 7, I-56126 Pisa (Italy)

2004-06-01T23:59:59.000Z

69

Absorption by cold Fermi atoms in a harmonic trap  

E-Print Network [OSTI]

We study the absorption spectrum for a strongly degenerate Fermi gas confined in a harmonic trap. The spectrum is calculated using both the exact summation and also the Thomas-Fermi (TF) approximation. In the latter case, relatively simple analytical expressions are obtained for the absorption lineshape at large number of trapped atoms. At zero temperature, the approximated lineshape is characterized by a $(1-z^2)^{5/2}$ dependence which agrees well with the exact numerical calculations. At non-zero temperature, the spectrum becomes broader, although remains non-Gaussian as long as the fermion gas is degenerate. The changes in the trap frequency for an electronically excited atom can introduce an additional line broadening.

Gediminas Juzeliunas; Marius Masalas

2000-11-10T23:59:59.000Z

70

Holographic non-Fermi liquid in a background magnetic field  

SciTech Connect (OSTI)

We study the effects of a nonzero magnetic field on a class of 2+1 dimensional non-Fermi liquids, recently found in [Hong Liu, John McGreevy, and David Vegh, arXiv:0903.2477.] by considering properties of a Fermionic probe in an extremal AdS{sup 4} black hole background. Introducing a similar fermionic probe in a dyonic AdS{sup 4} black hole geometry, we find that the effect of a magnetic field could be incorporated in a rescaling of the probe fermion's charge. From this simple fact, we observe interesting effects like gradual disappearance of the Fermi surface and quasiparticle peaks at large magnetic fields and changes in other properties of the system. We also find Landau level like structures and oscillatory phenomena similar to the de-Haas-van Alphen effect.

Basu, Pallab; He Jianyang; Mukherjee, Anindya; Shieh, Hsien-Hang [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada)

2010-08-15T23:59:59.000Z

71

Realization of SU(2)*SU(6) Fermi System  

E-Print Network [OSTI]

We report the realization of a novel degenerate Fermi mixture with an SU(2)*SU(6) symmetry in a cold atomic gas. We successfully cool the mixture of the two fermionic isotopes of ytterbium 171Yb with the nuclear spin I=1/2 and 173Yb with I=5/2 below the Fermi temperature T_ F as 0.46T_F for 171Yb and 0.54T_F for 173Yb. The same scattering lengths for different spin components make this mixture featured with the novel SU(2)*SU(6) symmetry. The nuclear spin components are separately imaged by exploiting an optical Stern-Gerlach effect. In addition, the mixture is loaded into a 3D optical lattice to implement the SU(2)*SU(6) Hubbard model. This mixture will open the door to the study of novel quantum phases such as a spinor Bardeen-Cooper-Schrieffer-like fermionic superfluid.

Taie, Shintaro; Sugawa, Seiji; Yamazaki, Rekishu; Tsujimoto, Takuya; Murakami, Ryo; Takahashi, Yoshiro

2010-01-01T23:59:59.000Z

72

The spectral problem of the ABJ Fermi gas  

E-Print Network [OSTI]

The partition function on the three-sphere of ABJ theory can be rewritten into a partition function of a non-interacting Fermi gas, with an accompanying one-particle Hamiltonian. We study the spectral problem defined by this Hamiltonian. We determine the exact WKB quantization condition, which involves quantities from refined topological string theory, and test it successfully against numerical calculations of the spectrum.

Johan Kallen

2014-07-02T23:59:59.000Z

73

THE FIRST FERMI-LAT GAMMA-RAY BURST CATALOG  

SciTech Connect (OSTI)

In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (?> 20 MeV) ?-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above ?20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model.

Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Asano, K. [Interactive Research Center of Science, Tokyo Institute of Technology, Meguro City, Tokyo 152-8551 (Japan); Axelsson, M. [Department of Astronomy, Stockholm University, SE-106 91 Stockholm (Sweden); Baldini, L. [Universitŕ di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d'Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bechtol, K.; Bloom, E. D. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bhat, P. N. [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Bissaldi, E. [Institut für Astro- und Teilchenphysik and Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, A-6020 Innsbruck (Austria); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Bonnell, J.; Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bouvier, A., E-mail: nicola.omodei@stanford.edu, E-mail: giacomov@slac.stanford.edu [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); and others

2013-11-01T23:59:59.000Z

74

CONSTRAINING THE HIGH-ENERGY EMISSION FROM GAMMA-RAY BURSTS WITH FERMI  

SciTech Connect (OSTI)

We examine 288 gamma-ray bursts (GRBs) detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field of view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no evidence for emission above 100 MeV. We report the photon flux upper limits in the 0.1-10 GeV range during the prompt emission phase as well as for fixed 30 s and 100 s integrations starting from the trigger time for each burst. We compare these limits with the fluxes that would be expected from extrapolations of spectral fits presented in the first GBM spectral catalog and infer that roughly half of the GBM-detected bursts either require spectral breaks between the GBM and LAT energy bands or have intrinsically steeper spectra above the peak of the {nu}F{sub {nu}} spectra (E{sub pk}). In order to distinguish between these two scenarios, we perform joint GBM and LAT spectral fits to the 30 brightest GBM-detected bursts and find that a majority of these bursts are indeed softer above E{sub pk} than would be inferred from fitting the GBM data alone. Approximately 20% of this spectroscopic subsample show statistically significant evidence for a cutoff in their high-energy spectra, which if assumed to be due to {gamma}{gamma} attenuation, places limits on the maximum Lorentz factor associated with the relativistic outflow producing this emission. All of these latter bursts have maximum Lorentz factor estimates that are well below the minimum Lorentz factors calculated for LAT-detected GRBs, revealing a wide distribution in the bulk Lorentz factor of GRB outflows and indicating that LAT-detected bursts may represent the high end of this distribution.

Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R.; Cameron, R. A.; Charles, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L.; Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Bouvier, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Brigida, M. [Dipartimento di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy); Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Caliandro, G. A., E-mail: jchiang@slac.stanford.edu, E-mail: kocevski@slac.stanford.edu, E-mail: moretti@particle.kth.se, E-mail: connauv@uah.edu, E-mail: valerie@nasa.gov, E-mail: michael.briggs@nasa.gov [Institut de Ciencies de l'Espai (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain); Collaboration: Fermi Large Area Telescope Team; Fermi Gamma-ray Burst Monitor Team; and others

2012-08-01T23:59:59.000Z

75

E-Print Network 3.0 - atic fermi egret Sample Search Results  

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

Gamma-ray Burst Monitor (GBM) - Large Area Telescope (LAT) The High... -Energy Gamma-ray Sky Bursts, blazars, pulsars, and more Fermi LAT Searches ... Source: Maryland at...

76

Dark matter annihilation and the PAMELA, FERMI, and ATIC anomalies  

SciTech Connect (OSTI)

If dark matter annihilation accounts for the tantalizing excess of cosmic ray electron/positrons, as reported by the PAMELA, ATIC, HESS, and FERMI observatories, then the implied annihilation cross section must be relatively large. This results, in the context of standard cosmological models, in very small relic dark matter abundances that are incompatible with astrophysical observations. We explore possible resolutions to this apparent conflict in terms of nonstandard cosmological scenarios; plausibly allowing for large cross sections, while maintaining relic abundances in accord with current observations.

El Zant, A. A.; Okada, H. [Centre for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No, 11837, Post Office Box 43 (Egypt); Khalil, S. [Centre for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No, 11837, Post Office Box 43 (Egypt); Department of Mathematics, Ain Shams University, Faculty of Science, Cairo, 11566 (Egypt)

2010-06-15T23:59:59.000Z

77

Detroit Edison's Fermi 1 - Preparation for Reactor Removal  

SciTech Connect (OSTI)

This paper is intended to provide information about the ongoing decommissioning tasks at Detroit Edison's Fermi 1 plant, and in particular, the work being performed to prepare the reactor for removal and disposal. In 1972 Fermi 1 was shutdown and the fuel returned to the Atomic Energy Commission. By the end of 1975, a retirement plan was prepared, the bulk sodium removed, and the plant placed in a safe store condition. The plant systems were left isolated with the sodium containing systems inert with carbon dioxide in an attempt to form a carbonate layer, thus passivating the underlying reactive sodium. In 1996, Detroit Edison determined to evaluate the condition of the plant and to make recommendations in relation to the Fermi 1 future plans. At the end of 1997 approval was obtained to remove the bulk asbestos and residual alkali-metals (i.e., sodium and sodium potassium (NaK)). In 2000, full nuclear decommissioning of the plant was approved. To date, the bulk asbestos insulation has been removed, and the only NaK remaining is located in six capillary instrument tubes. The remaining sodium is contained within the reactor, two of the three primary loops, and miscellaneous removed pipes and equipment to be processed. The preferred method for removing or reacting sodium at Fermi 1 is by injecting superheated steam into a heated, nitrogen inert system. The byproducts of this reaction are caustic sodium hydroxide, hydrogen gas, and heat. The decision was made to separate the three primary loops from the reactor for better control prior to processing each loop and the reactor separately. The first loop has already been processed. The main focus is now to process the reactor to allow removal and disposal of the Class C waste prior to the anticipated June 2008 closure of the Barnwell radioactive waste disposal facility located in South Carolina. Lessons learnt are summarized and concern: the realistic schedule and adherence to the schedule, time estimates, personnel accountability, back up or fill in work, work packages, condensation control, radiological contamination control, and organization of the waste stream.

Swindle, Danny [Sargent and Lundy Engineers, LLC, 55 E. Monroe Street, Chicago, IL 60603 (United States)

2008-01-15T23:59:59.000Z

78

Coherent state of a weakly interacting ultracold Fermi gas  

E-Print Network [OSTI]

We examine the weakly interacting atoms in an ultracold Fermi gas leading to a state of macroscopic coherence, from a theoretical perspective. It has been shown that this state can be described as a fermionic coherent state. These coherent states are the eigenstates of fermionic annihilation operators, the eigenvalues being anti-commuting numbers or Grassmann numbers. By exploiting the simple rules of Grassmann algebra and a close kinship between relations evaluated for more familiar bosonic fields and those for fermionic fields, we derive the thermodynamic limit, the spontaneous symmetry breaking and the quasi-particle spectrum of the fermionic system.

Arnab Ghosh; Sudarson Sekhar Sinha; Deb Shankar Ray

2013-04-04T23:59:59.000Z

79

Quantum thermodynamic fluctuations of a chaotic Fermi-gas model  

E-Print Network [OSTI]

We investigate the thermodynamics of a Fermi gas whose single-particle energy levels are given by the complex zeros of the Riemann zeta function. This is a model for a gas, and in particular for an atomic nucleus, with an underlying fully chaotic classical dynamics. The probability distributions of the quantum fluctuations of the grand potential and entropy of the gas are computed as a function of temperature and compared, with good agreement, with general predictions obtained from random matrix theory and periodic orbit theory (based on prime numbers). In each case the universal and non--universal regimes are identified.

P. Leboeuf; A. G. Monastra

2003-02-28T23:59:59.000Z

80

PHOTOMETRICALLY TRIGGERED KECK SPECTROSCOPY OF FERMI BL LACERTAE OBJECTS  

SciTech Connect (OSTI)

We report on Keck spectra of 10 Fermi blazars. J0622+3326, previously unobserved, is shown to be a flat-spectrum radio quasar at redshift z = 1.062. The others are known BL Lac type objects that have resisted previous attempts to secure redshifts. Using a photometric monitoring campaign with the 0.76 m Katzman Automatic Imaging Telescope at Lick Observatory, we identified epochs when the relativistic jet emission was fainter than usual, thus triggering the Keck spectroscopy. This strategy gives improved sensitivity to stars and ionized gas in the host galaxy, thereby providing improved redshift constraints for seven of these sources.

Shaw, Michael S.; Romani, Roger W. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States); Filippenko, Alexei V.; Cenko, S. Bradley; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2013-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

Enrico Fermi's Impact on Science - John Marburger Speech  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia NanoparticlesSmartAffects the Future EnergyEnolSpectrometryEnricoFermi

82

#k Fermi National Accelerator Laboratory FRRMILAEFPub-90/198-A  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNG IHDR€ÍSolar Energy41 (Dollars and Sense Committee)Energyk Fermi National

83

Investigation of the deformed fermi surfaces mechanism for pairing of two species of fermions with mismatched fermi surfaces  

E-Print Network [OSTI]

(Fulde and Ferrell) state, and give our reasons why we need to investigate the DFS(Deformed Fermi Surface) states for superconductor. In chapter II, we will find depairing(or blocking) regions of the the DFS state. In chapter III, we use a trial ground state wave... function to investigate the chemical potential and minimize the original Hamiltonian of S-wave superconductor. And some computer programs used in Chapter III are attached to the appendix. Chapter IV is the conclusion. B. BCS Theory In 1957, John Bardeen...

Lu, Jianxu

2008-10-10T23:59:59.000Z

84

Simulating strongly correlated electrons with a strongly interacting Fermi gas  

SciTech Connect (OSTI)

The quantum many-body physics of strongly-correlated fermions is studied in a degenerate, strongly- interacting atomic Fermi gas, first realized by our group with DOE support in 2002. This system, which exhibits strong spin pairing, is now widely studied and provides an important paradigm for testing predictions based on state-of-the-art many-body theory in fields ranging from nuclear matter to high temperature superfluidity and superconductivity. As the system is strongly interacting, both the superfluid and the normal fluid are nontrivial and of great interest. A central part of our program on Fermi gases is the connection between the study of thermodynamics, supported by DOE and the study of hydrodynamic transport, supported by NSF. This connection is especially interesting in view of a recent conjecture from the string theory community on the concept of nearly perfect normal fluids, which exhibit a minimum ratio of shear viscosity to entropy density in strongly-interacting, scale-invariant systems.

Thomas, John E. [North Carolina State University

2013-05-28T23:59:59.000Z

85

ccsd00000540 Production of Long-Lived Ultracold Li 2 Molecules from a Fermi gas  

E-Print Network [OSTI]

and sign of the scattering length. In bosonic samples, the collapse of Bose-Einstein condensates (BEC a Fermi gas J. Cubizolles 1 , T. Bourdel 1 , S. J. J. M. F. Kokkelmans 1 , G.V. Shlyapnikov 1;2;3 and C-bound Li2 molecules from a degenerate two component Fermi gas by sweeping a magnetic #12;eld across

86

PHYSICAL REVIEW A 87, 012703 (2013) Feshbach-molecule formation in a Bose-Fermi mixture  

E-Print Network [OSTI]

-degenerate Fermi gas of polar molecules would be an important step toward achieving novel quantum phases of matter molecules with a conversion efficiency as high as 45%. In the limit of fast magnetic sweeps and small of bosonic molecules from either Bose or Fermi gases. However, for quantum degenerate atom gas mixtures, we

Jin, Deborah

87

FermiQCD: A tool kit for parallel lattice QCD applications  

SciTech Connect (OSTI)

We present here the most recent version of FermiQCD, a collection of C++ classes, functions and parallel algorithms for lattice QCD, based on Matrix Distributed Processing. FermiQCD allows fast development of parallel lattice applications and includes some SSE2 optimizations for clusters of Pentium 4 PCs.

Di Pierro, Massimo

2002-03-01T23:59:59.000Z

88

Fermi Surface of Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory  

E-Print Network [OSTI]

Fermi Surface of ­Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 DC Field Facility User Program The fermi surface of ­Uranium has been measured surface of alpha-uranium at ambient pressure, Phys. Rev. B Rapid Commun., 80, 241101 (2009). B//c-axis B

Weston, Ken

89

In-medium effects for nuclear matter in the Fermi energy domain D. Durand,1  

E-Print Network [OSTI]

In-medium effects for nuclear matter in the Fermi energy domain O. Lopez,1 D. Durand,1 G. Lehaut,1 of nuclear reactions in the Fermi energy domain. I. INTRODUCTION Transport properties in nuclear matter energy domain, transport features should exhibit the in- terplay between mean-field (nuclear degrees

Boyer, Edmond

90

Implication of Tsallis entropy in the Thomas–Fermi model for self-gravitating fermions  

SciTech Connect (OSTI)

The Thomas–Fermi approach for self-gravitating fermions is revisited within the theoretical framework of the q-statistics. Starting from the q-deformation of the Fermi–Dirac distribution function, a generalized Thomas–Fermi equation is derived. It is shown that the Tsallis entropy preserves a scaling property of this equation. The q-statistical approach to Jeans’ instability in a system of self-gravitating fermions is also addressed. The dependence of the Jeans’ wavenumber (or the Jeans length) on the parameter q is traced. It is found that the q-statistics makes the Fermionic system unstable at scales shorter than the standard Jeans length. -- Highlights: •Thomas–Fermi approach for self-gravitating fermions. •A generalized Thomas–Fermi equation is derived. •Nonextensivity preserves a scaling property of this equation. •Nonextensive approach to Jeans’ instability of self-gravitating fermions. •It is found that nonextensivity makes the Fermionic system unstable at shorter scales.

Ourabah, Kamel; Tribeche, Mouloud, E-mail: mouloudtribeche@yahoo.fr

2014-03-15T23:59:59.000Z

91

A Vlasov-Maxwell Solver to Study Microbunching Instability in the FERMI@ELETTRA First Bunch Compressor System  

E-Print Network [OSTI]

A Vlasov-Maxwell Solver to Study Microbunching Instability in the FERMI@ELETTRA First Bunch Compressor System

Bassi, G; Ellison, J A; Heinemann, K A

2008-01-01T23:59:59.000Z

92

Entire Complacency and Satisfaction  

E-Print Network [OSTI]

Posted originally on the Archive of Our Own at http://archiveofourown.org/works/37739. Rating: General Audiences Archive Warning: No Archive Warnings Apply Category: F/F Fandom: Mina de Malfois Character: Archivist12, Mina de Malfois - Character... be purchased in whatever country she was wandering through, and all of which cost a small fortune to procure and mail out. But anyway, I didn't know if I was just Arc's most frequent guest, or if we kind of almost lived together, until after I'd left fandom (I...

2009-12-24T23:59:59.000Z

93

Properties of Entire Functions  

E-Print Network [OSTI]

of our subject depends' The first three theorems will be stated without proof. THEOREM (1-1) (Identity theorem). If f(z) snd g(z) are analytic in a connected region R, and f(z) =' g(z) over a set of points M having a limit point in R, then f(z) = g(z... ) in RE mEOHEM (1-2). L*t (f ( 1) ( =1. 2, " ~ ) b q * of functions such that (1) f (z) (n=li2~ ~ ~ ~ ) is analytic in the region R, (2) the sequence converges uniformly to f(z) in RE Then f(z) is analytic in R, THEOREM (1-3) (Principle...

Hunkler, Richard F

1960-01-01T23:59:59.000Z

94

Exponential Decay and Fermi's Golden Rule from an Uncontrolled Quantum Zeno Effect  

E-Print Network [OSTI]

We modify the theory of the Quantum Zeno Effect to make it consistent with the postulates of quantum mechanics. This modification allows one, throughout a sequence of observations of an excited system, to address the nature of the observable and thereby to distinguish survival from non-decay, which is necessary whenever excited states are degenerate. As a consequence, one can determine which types of measurements can possibly inhibit the exponential decay of the system. We find that continuous monitoring taken as the limit of a sequence of ideal measurements will only inhibit decay in special cases, such as in well-controlled experiments. Uncontrolled monitoring of an unstable system, however, can cause exponentially decreasing non-decay probability at all times. Furthermore, calculating the decay rate for a general sequence of observations leads to a straightforward derivation of Fermi's Golden Rule, that avoids many of the conceptual difficulties normally encountered. When multiple decay channels are available, the derivation reveals how the total decay rate naturally partitions into a sum of the decay rates for the various channels, in agreement with observations. Continuous and unavoidable monitoring of an excited system by an uncontrolled environment may therefore be a mechanism by which to explain the exponential decay law.

P. W. Bryant

2014-10-14T23:59:59.000Z

95

Gamma-ray halo around the M31 galaxy as seen by the Fermi LAT  

E-Print Network [OSTI]

Theories of galaxy formation predict the existence of extended gas halo around spiral galaxies. If there are 10-100 nG magnetic fields at several ten kpc distances from the galaxies, extended galactic cosmic ray (CR) haloes could also exist. Galactic CRs could interact with the tenuous hot halo gas to produce observable $\\gamma$-rays. In this paper we have performed search for such a halo around the M31 galaxy -- the closest large spiral galaxy. Our analysis of 5.5 years of the Fermi LAT data revealed the presence of a spatially extended emission excess around M31. The data can be fitted using the simplest morphology of a uniformly bright circle. The best fit gave a 4.4$\\sigma$ significance for a $3^{\\circ}$ (40 kpc) halo with photon flux of $\\sim (1.9\\pm1.1)\\times 10^{-9} ~\\mathrm{cm^{-2}s^{-1}}$ and luminosity $(8.4\\pm4.6)\\times 10^{38} ~\\mathrm{erg~s^{-1}}$ in the energy range 0.3--100 GeV. The presence of such a halo compellingly shows that a 10-100 nG magnetic field should extend around M31 up to a 40 kp...

Pshirkov, M S; Postnov, K A

2015-01-01T23:59:59.000Z

96

Finite-size energy of non-interacting Fermi gases  

E-Print Network [OSTI]

We prove the asymptotics of the difference of the ground-state energies of two non-interacting $N$-particle Fermi gases on the half line of length $L$ in the thermodynamic limit up to order $1/L$. We are particularly interested in subdominant terms proportional to $1/L$, called finite-size energy. In the nineties Affleck and co-authors [Aff97, ZA97, AL94] claimed that the finite-size energy equals the decay exponent occuring in Anderson's orthogonality catastrophe. It turns out that the finite-size energy depends on the details of the thermodynamic limit and typically also includes a linear term in the scattering phase shift.

Martin Gebert

2014-06-14T23:59:59.000Z

97

Effective interaction approach to the Fermi hard-sphere system  

E-Print Network [OSTI]

The formalism based on correlated basis functions and the cluster expansion technique has been recently employed to derive an effective interaction from a realistic nuclear hamiltonian. To gauge the reliability of this scheme, we perform a systematic comparison between the results of its application to the Fermi hard-sphere system and the predictions obtained from low-density expansions, as well as from other many-body techniques. The analysis of a variety of properties, including the ground state energy, the effective mass and the momentum distribution, shows that the effective interaction approach is remarkably accurate, thus suggesting that it may be employed to achieve a consistent description of the structure and dynamics of nuclear matter in the density region relevant to astrophysical applications.

Angela Mecca; Alessandro Lovato; Omar Benhar; Artur Polls

2014-10-31T23:59:59.000Z

98

On the thermalization of the $?$-Fermi-Pasta-Ulam system  

E-Print Network [OSTI]

We study theoretically the original $\\alpha$-Fermi-Pasta-Ulam (FPU) system with $N=16,32$ and $64$ masses connected by a nonlinear quadratic spring. Our approach is based on resonant wave-wave interaction theory. We show that the route to thermalization consists of three stages. The first one is associated with non-resonant three-wave interactions. At this short time scale, the dynamics is reversible; this stage coincides with the observation of recurrent phenomena in numerical simulations of the $\\alpha$-FPU. On a larger time scale, exact four-wave resonant interactions start to take place; however, we find that all quartets are isolated, preventing a full mixing of energy in the spectrum and thermalization. The last stage corresponds to six-wave resonant interactions. Those are responsible for the energy equipartition recently observed in numerical simulations. A key role in our finding is played by the {\\it Umklapp} (flip over) resonant interactions, typical of discrete systems.

Miguel Onorato; Lara Vozella; Davide Proment; Yuri V. Lvov

2014-02-07T23:59:59.000Z

99

High-Energy Neutrinos in Light of Fermi-LAT  

E-Print Network [OSTI]

The production of high-energy astrophysical neutrinos is tightly linked to the emission of hadronic gamma-rays. I will discuss the recent observation of TeV to PeV neutrinos by the IceCube Cherenkov telescope in the context of gamma-ray astronomy. The corresponding energy range of hadronic gamma-rays is not directly accessible by extragalactic gamma-ray astronomy due to interactions with cosmic radiation backgrounds. Nevertheless, the isotropic sub-TeV gamma-ray background observed by the Fermi Large Area Telescope (LAT) contains indirect information from secondary emission produced in electromagnetic cascades and constrains hadronic emission scenarios. On the other hand, observation of PeV gamma-rays would provide a smoking-gun signal for Galactic emission. In general, the cross-correlation of neutrino emission with (extended) Galactic and extragalactic gamma-ray sources will serve as the most sensitive probe for a future identification of neutrino sources.

Ahlers, Markus

2015-01-01T23:59:59.000Z

100

SLAC All Access: Fermi Gamma-ray Space Telescope  

ScienceCinema (OSTI)

Three hundred and fifty miles overhead, the Fermi Gamma-ray Space Telescope silently glides through space. From this serene vantage point, the satellite's instruments watch the fiercest processes in the universe unfold. Pulsars spin up to 700 times a second, sweeping powerful beams of gamma-ray light through the cosmos. The hyperactive cores of distant galaxies spew bright jets of plasma. Far beyond, something mysterious explodes with unfathomable power, sending energy waves crashing through the universe. Stanford professor and KIPAC member Roger W. Romani talks about this orbiting telescope, the most advanced ever to view the sky in gamma rays, a form of light at the highest end of the energy spectrum that's created in the hottest regions of the universe.

Romani, Roger

2014-06-24T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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.


101

FERMI LARGE AREA TELESCOPE OBSERVATIONS OF GRB 110625A  

SciTech Connect (OSTI)

Gamma-ray bursts (GRBs) that emit photons at GeV energies form a small but significant population of GRBs. However, the number of GRBs whose GeV-emitting period is simultaneously observed in X-rays remains small. We report {gamma}-ray observations of GRB 110625A using Fermi's Large Area Telescope in the energy range 100 MeV-20 GeV. Gamma-ray emission at these energies was clearly detected using data taken between 180 s and 580 s after the burst, an epoch after the prompt emission phase. The GeV light curve differs from a simple power-law decay, and probably consists of two emission periods. Simultaneous Swift X-Ray Telescope observations did not show flaring behaviors as in the case of GRB 100728A. We discuss the possibility that the GeV emission is the synchrotron self-Compton radiation of underlying ultraviolet flares.

Tam, P. H. T.; Kong, A. K. H. [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fan Yizhong, E-mail: phtam@phys.nthu.edu.tw [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2012-08-01T23:59:59.000Z

102

PROBING CURVATURE EFFECTS IN THE FERMI GRB 110920  

SciTech Connect (OSTI)

Curvature effects in gamma-ray bursts (GRBs) have long been a source of considerable interest. In a collimated relativistic GRB jet, photons that are off-axis relative to the observer arrive at later times than on-axis photons and are also expected to be spectrally softer. In this work, we invoke a relatively simple kinematic two-shell collision model for a uniform jet profile and compare its predictions to GRB prompt-emission data for observations that have been attributed to curvature effects such as the peak-flux-peak-frequency relation, i.e., the relation between the ?F{sub ?} flux and the spectral peak, E{sub pk} in the decay phase of a GRB pulse, and spectral lags. In addition, we explore the behavior of pulse widths with energy. We present the case of the single-pulse Fermi GRB 110920 as a test for the predictions of the model against observations.

Shenoy, A.; Maximon, L. C.; Dhuga, K. S.; Parke, W. C.; Maclachlan, G. A.; Eskandarian, Ali [Department of Physics, The George Washington University, Washington, DC 20052 (United States); Sonbas, E. [Department of Physics, University of Adiyaman, 02040 Adiyaman (Turkey); Dermer, C. [Space Science Division, Code 7653, Naval Research Laboratory, Washington, DC 20375 (United States); Bhat, P. N. [CSPAR, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Hakkila, J. [Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States); Ukwatta, T. N., E-mail: ashwinsp469@gmail.com [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

2013-11-20T23:59:59.000Z

103

Fermi GBM Observations of Terrestrial Gamma-ray Flashes  

SciTech Connect (OSTI)

Terrestrial Gamma-ray Flashes are short pulses of energetic radiation associated with thunderstorms and lightning. While the Gamma-ray Burst Monitor (GBM) on Fermi was designed to observe gamma-ray bursts, its large BGO detectors are excellent for observing TGFs. Using GBM, TGF pulses are seen to either be symmetrical or have faster rise time than fall times. Some TGFs are resolved into double, partially overlapping pulses. Using ground-based radio observations of lightning from the World Wide Lightning Location Network (WWLLN), TGFs and their associated lightning are found to be simultaneous to {approx_equal}40 {mu} s. The lightning locations are typically within 300 km of the sub-spacecraft point.

Briggs, Michael S. [CSPAR, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States)

2011-09-21T23:59:59.000Z

104

Kolmogorov Complexity, String Information, Panspermia and the Fermi Paradox  

E-Print Network [OSTI]

Bit strings rather than byte files can be a mode of transmission both for intelligent signals and for travels of extraterrestrial life. Kolmogorov complexity, i.e. the minimal length of a binary coded string completely defining a system, can then, due to its universality, become a key concept in the strategy of the search of extraterrestrials. Evaluating, for illustration, the Kolmogorov complexity of the human genome, one comes to an unexpected conclusion that a low complexity compressed string - analog of Noah's ark - will enable the recovery of the totality of terrestrial life. The recognition of bit strings of various complexity up to incompressible Martin-L\\"{o}f random sequences, will require a different strategy for the analysis of the cosmic signals. The Fermi paradox "Where is Everybody?" can be viewed under in the light of such information panspermia, i.e. a Universe full of traveling life streams.

V. G. Gurzadyan

2005-09-26T23:59:59.000Z

105

Fermi Normal Coordinates and Fermion Curvature Couplings in General Relativity  

E-Print Network [OSTI]

We study gravitational curvature effects in circular and radial geodesics in static, spherically symmetric space-times, using Fermi normal coordinates. We first set up these coordinates in the general case, and then use this to study effective magnetic fields due to gravitational curvature in the exterior and interior Schwarzschild, Janis-Newman-Winicour, and Bertrand space-times. We show that these fields can be large for specific parameter values in the theories, and thus might have observational significance. We discuss the qualitative differences of the magnetic field for vacuum space-times and for those seeded by matter. We estimate the magnitude of these fields in realistic galactic scenarios and discuss their possible experimental relevance. Gravitational curvature corrections to the Hydrogen atom spectrum for these space-times are also discussed briefly.

Anshuman Dey; Abhisek Samanta; Tapobrata Sarkar

2014-03-18T23:59:59.000Z

106

GRB 110709A, 111117A, AND 120107A: FAINT HIGH-ENERGY GAMMA-RAY PHOTON EMISSION FROM FERMI-LAT OBSERVATIONS AND DEMOGRAPHIC IMPLICATIONS  

SciTech Connect (OSTI)

Launched on 2008 June 11, the Large Area Telescope (LAT) instrument on board the Fermi Gamma-ray Space Telescope has provided a rare opportunity to study high-energy photon emission from gamma-ray bursts (GRBs). Although the majority of such events (27) have been identified by the Fermi-LAT Collaboration, four were uncovered by using more sensitive statistical techniques. In this paper, we continue our earlier work by finding three more GRBs associated with high-energy photon emission, GRB 110709A, 111117A, and 120107A. To systematize our matched filter approach, a pipeline has been developed to identify these objects in nearly real time. GRB 120107A is the first product of this analysis procedure. Despite the reduced threshold for identification, the number of GRB events has not increased significantly. This relative dearth of events with low photon number prompted a study of the apparent photon number distribution. We find an extremely good fit to a simple power law with an exponent of -1.8 {+-} 0.3 for the differential distribution. As might be expected, there is a substantial correlation between the number of lower energy photons detected by the Gamma-ray Burst Monitor (GBM) and the number observed by LAT. Thus, high-energy photon emission is associated with some but not all of the brighter GBM events. Deeper studies of the properties of the small population of high-energy emitting bursts may eventually yield a better understanding of these entire phenomena.

Zheng Weikang; Akerlof, Carl W.; McKay, Timothy A. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Pandey, Shashi B. [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263129 (India); Zhang Binbin [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Zhang Bing [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States); Sakamoto, Takanori, E-mail: zwk@umich.edu [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-01T23:59:59.000Z

107

Fermi-Boltzmann statistics of neutrinos and relativistic effective degrees of freedom  

E-Print Network [OSTI]

We investigate the effect of the presence of non-pure fermionic neutrinos on the relativistic effective degrees of freedom in the early universe. The statistics of neutrinos is transformed continuously from Fermi-Dirac to Maxwell-Boltzmann statistics. We find that the relativistic degrees of freedom decreases with the deviation from pure Fermi-Dirac statistics of neutrinos if there are constant and large lepton asymmetries. Additionally, we confirm that the change of the statistics of neutrinos from Fermi-Dirac to Maxwell-Boltzmann is not sufficient to cover the excess of the effective number of neutrinos.

Jun Iizuka; Teruyuki Kitabayashi

2014-11-22T23:59:59.000Z

108

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High EnergyEliane SJuly 2007Fermi NationalFermiFermi

109

Search for evidence of cosmic ray acceleration by supernova Remnant Kes 41 using the Fermi LAT  

E-Print Network [OSTI]

The analysis presented in this paper incorporated photon events received during the full run time of the Fermi Gamma Space Telescope (FGST) Large Area Telescope (LAT) to date. By studying the [gamma]y emission of the ...

Joubert, Timothy Robert

2013-01-01T23:59:59.000Z

110

Fermi-Energy-Dependent Structural Deformation of Chiral Single-Wall Carbon Nanotubes  

E-Print Network [OSTI]

In this work, we use an extended tight-binding approach for calculating the Fermi-energy dependence of the structural deformation of chiral single-wall carbon nanotubes (SWNTs). We show that, in general, nanotube strains ...

Vieira, Bruno G.?M.

111

Nonadiabatic phenomenology in small Fermi energy superconductors L. Pietronero a,b  

E-Print Network [OSTI]

Nonadiabatic phenomenology in small Fermi energy superconductors L. Pietronero a,b , E. Cappelluti hypothesis is of fundamental importance in the standard electron­phonon phenomenology, since it not only

Cappelluti, Emmanuele

112

Beam energy spread in FERMI@elettra gun and linac induced by intrabeam scattering  

E-Print Network [OSTI]

spread in FERMI@elettra gun and linac induced by intrabeamcathode area in the electron guns know in the literature asmost visible within the electron gun where the electron beam

Zholents, Alexander A

2008-01-01T23:59:59.000Z

113

Realization of effective super Tonks-Girardeau gases via strongly attractive one-dimensional Fermi gases  

SciTech Connect (OSTI)

A significant feature of the one-dimensional super Tonks-Girardeau gas is its metastable gas-like state with a stronger Fermi-like pressure than for free fermions which prevents a collapse of atoms. This naturally suggests a way to search for such strongly correlated behavior in systems of interacting fermions in one dimension. We thus show that the strongly attractive Fermi gas without polarization can be effectively described by a super Tonks-Girardeau gas composed of bosonic Fermi pairs with attractive pair-pair interaction. A natural description of such super Tonks-Girardeau gases is provided by Haldane generalized exclusion statistics. In particular, they are equivalent to ideal particles obeying more exclusive statistics than Fermi-Dirac statistics.

Chen Shu; Yin Xiangguo; Guan Liming [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Guan Xiwen [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Batchelor, M. T. [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Mathematical Sciences Institute, Australian National University, Canberra ACT 0200 (Australia)

2010-03-15T23:59:59.000Z

114

Estimating the energy of stitching together the Maxwell and Fermi neutron spectra  

SciTech Connect (OSTI)

The energy of stitching together the Maxwell and Fermi spectra is estimated on the basis of experimental data and the results of calculations carried out using the MCU-RFFI and MCU-5 codes.

Ionov, V. S., E-mail: ivs2010@vver.kiae.ru; Marin, S. V. [National Research Center Kurchatov Institute (Russian Federation)

2014-12-15T23:59:59.000Z

115

Improved Measurement of the Muon Lifetime and Determination of the Fermi Constant  

E-Print Network [OSTI]

The MuLan collaboration has measured the lifetime of the positve muon to a precision of 1.0 parts per million. The Fermi constant is determined to a precision of 0.6 parts per million.

P. T. Debevec

2011-08-22T23:59:59.000Z

116

Deuterium-Tritium Pulse Propulsion with Hydrogen as Propellant and the Entire Spacecraft as a Gigavolt Capacitor for Ignition  

E-Print Network [OSTI]

A deuterium-tritium (DT) nuclear pulse propulsion concept for fast interplanetary transport is proposed utilizing almost all the energy for thrust and without the need for a large radiator: 1. By letting the thermonuclear micro-explosion take place in the center of a liquid hydrogen sphere with the radius of the sphere large enough to slow down and absorb the neutrons of the DT fusion reaction, heating the hydrogen to a fully ionized plasma at a temperature of ~ 105 K. 2. By using the entire spacecraft as a magnetically insulated gigavolt capacitor, igniting the DT micro-explosion with an intense GeV ion beam discharging the gigavolt capacitor, possible if the space craft has the topology of a torus.

Winterberg, Friedwardt

2012-01-01T23:59:59.000Z

117

Deuterium-Tritium Pulse Propulsion with Hydrogen as Propellant and the Entire Spacecraft as a Gigavolt Capacitor for Ignition  

E-Print Network [OSTI]

A deuterium-tritium (DT) nuclear pulse propulsion concept for fast interplanetary transport is proposed utilizing almost all the energy for thrust and without the need for a large radiator: 1. By letting the thermonuclear micro-explosion take place in the center of a liquid hydrogen sphere with the radius of the sphere large enough to slow down and absorb the neutrons of the DT fusion reaction, heating the hydrogen to a fully ionized plasma at a temperature of ~ 105 K. 2. By using the entire spacecraft as a magnetically insulated gigavolt capacitor, igniting the DT micro-explosion with an intense GeV ion beam discharging the gigavolt capacitor, possible if the space craft has the topology of a torus.

Friedwardt Winterberg

2012-07-31T23:59:59.000Z

118

Fermi-LAT Observation of Supernova Remnant S147  

SciTech Connect (OSTI)

We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) x 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 x 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with prominent H{alpha} filaments of S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. Reacceleration of pre-existing CRs and subsequent adiabatic compression in the filaments is sufficient to provide the required energy density of high-energy protons.

Katsuta, J.; Uchiyama, Y.; Tanaka, T.; /SLAC /KIPAC, Menlo Park; Tajima, H.; /SLAC /KIPAC, Menlo Park /Nagoya U., Solar-Terrestrial Environ. Lab.; Bechtol, K.; Funk, S.; Lande, J.; /SLAC /KIPAC, Menlo Park; Ballet, J.; /AIM, Saclay; Hanabata, Y.; /Hiroshima U.; Lemoine-Goumard, M.; /CENBG, Gradignan; Takahashi, T.; /JAXA, Sagamihara

2012-08-17T23:59:59.000Z

119

Experiences with string matching on the Fermi Architecture  

SciTech Connect (OSTI)

String matching is at the core of many real-world applications, such as security, bioinformatic, data mining. All these applications requires the ability to match always growing data sets against large dictionaries effectively, fastly and possibly in real time. Unfortunately, string matching is a computationally intensive procedure which poses significant challenges on current software and hardware implementations. Graphic Processing Units (GPU) have become an interesting target for such high-throughput applications, but the algorithms and the data structures need to be redesigned to be parallelized and adapted to the underlining hardware, coping with the limitations imposed by these architectures. In this paper we present an efficient implementation of the Aho-Corasick string matching algorithm on GPU, showing how we progressively redesigned the algorithm and the data structures to fit on the architecture. We then evaluate the implementation on single and multiple Tesla C2050 (T20 ``Fermi'' based) boards, comparing them to the previous Tesla C1060 (T10 based) solutions and equivalent multicore implementations on x86 CPUs. We discuss the various tradeoffs of the different architectures.

Tumeo, Antonino; Secchi, Simone; Villa, Oreste

2011-02-25T23:59:59.000Z

120

Finite-temperature study of Bose-Fermi superfluid mixtures  

SciTech Connect (OSTI)

Ultracold atom experiments offer the unique opportunity to study mixing of different types of superfluid states. Our interest is in superfluid mixtures comprising of particles with different statistics--Bose and Fermi. Such scenarios occur naturally, for example, in dense quantum chromodynamics (QCD) matter. Interestingly, cold atomic experiments are performed in traps with finite spatial extent, thus critically destabilizing the occurrence of various homogeneous phases. Critical to this analysis is the understanding that the trapped system can undergo phase separation, resulting in a unique situation where phase transition in either species (bosons or fermions) can overlap with the phase separation between possible phases. In the present work, we illustrate how this intriguing interplay manifests in an interacting two-species atomic mixture--one bosonic and another fermionic with two spin components--within a realistic trap configuration. We further show that such interplay of transitions can render the nature of the ground state to be highly sensitive to the experimental parameters and the dimensionality of the system.

Ramachandhran, B.; Pu, H. [Department of Physics and Astronomy, and Rice Quantum Institute, Rice University, Houston, Texas 77005 (United States); Bhongale, S. G. [Department of Physics and Astronomy, and Rice Quantum Institute, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, George Mason University, MS 3F3, Fairfax, Virginia 22030 (United States)

2011-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" from the National Library of EnergyBeta (NLEBeta).
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121

Multi-wavelength Emission from the Fermi Bubble III. Stochastic (Fermi) Re-Acceleration of Relativistic Electrons Emitted by SNRs  

E-Print Network [OSTI]

We analyse the model of stochastic re-acceleration of electrons, which are emitted by supernova remnants (SNRs) in the Galactic Disk and propagate then into the Galactic halo, in order to explain the origin on nonthermal (radio and gamma-ray) emission from the Fermi Bubbles (FB). We assume that the energy for re-acceleration in the halo is supplied by shocks generated by processes of star accretion onto the central black hole. Numerical simulations show that regions with strong turbulence (places for electron re-acceleration) are located high up in the Galactic Halo about several kpc above the disk. The energy of SNR electrons that reach these regions does not exceed several GeV because of synchrotron and inverse Compton energy losses. At appropriate parameters of re-acceleration these electrons can be re-accelerated up to the energy 10E12 eV which explains in this model the origin of the observed radio and gamma-ray emission from the FB. However although the model gamma-ray spectrum is consistent with the Fe...

Cheng, K S; Dogiel, V A; Ko, C M

2015-01-01T23:59:59.000Z

122

Fermi Discovery of Gamma-Ray Emission from NGC 1275  

SciTech Connect (OSTI)

We report the discovery of high-energy (E > 100 MeV) {gamma}-ray emission from NGC 1275, a giant elliptical galaxy lying at the center of the Perseus cluster of galaxies, based on observations made with the Large Area Telescope (LAT) of the Fermi Gamma-ray Space Telescope. The positional center of the {gamma}-ray source is only {approx}3{prime} away from the NGC 1275 nucleus, well within the 95% LAT error circle of {approx}5{prime}. The spatial distribution of {gamma}-ray photons is consistent with a point source. The average flux and power-law photon index measured with the LAT from 2008 August 4 to 2008 December 5 are F{sub {gamma}} = (2.10 {+-} 0.23) x 10{sup -7} ph (>100 MeV) cm{sup -2} s{sup -1} and {Gamma} = 2.17 {+-} 0.05, respectively. The measurements are statistically consistent with constant flux during the four-month LAT observing period. Previous EGRET observations gave an upper limit of F{sub {gamma}} < 3.72 x 10{sup -8} ph (>100 MeV) cm{sup -2} s{sup -1} to the {gamma}-ray flux from NGC 1275. This indicates that the source is variable on timescales of years to decades, and therefore restricts the fraction of emission that can be produced in extended regions of the galaxy cluster. Contemporaneous and historical radio observations are also reported. The broadband spectrum of NGC 1275 is modeled with a simple one-zone synchrotron/synchrotron self-Compton model and a model with a decelerating jet flow.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Asano, K.; /Tokyo Inst. Tech.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /SISSA, Trieste /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /ASDC, Frascati /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U.; /more authors..

2009-05-15T23:59:59.000Z

123

Milagro Observations of TeV Emission from Galactic Sources in the Fermi Bright Source List  

E-Print Network [OSTI]

We present the result of a search of Milagro sky map for spatial correlations with sources from a subset of the recent Fermi Bright Source List (BSL). The BSL consists of the 205 most significant sources detected above 100 MeV by the Fermi Large Area Telescope. We select sources based on their categorization in the BSL, taking all confirmed or possible Galactic sources in the field of view of Milagro. Of the 34 Fermi sources selected, 14 are observed by Milagro at a significance of 3 standard deviations or more. We conduct this search with a new analysis which employs newly-optimized gamma-hadron separation and utilizes the full 8-year Milagro dataset. Milagro is sensitive to gamma rays above 1 TeV and these results extend the observation of these sources far above the Fermi energy band. With the new analysis and additional data, TeV emission is definitively observed associated with the Fermi pulsar J2229.0+6114, in the the Boomerang Pulsar Wind Nebula (PWN). Furthermore, an extended region of TeV emission is...

Abdo, A A; Aune, T; Berley, D; Chen, C; Christopher, G E; DeYoung, T; Dingus, B L; Ellsworth, R W; González, M M; Goodman, J A; Hays, E; Hoffman, C M; Huentemeyer, P H; Kolterman, B E; Linnemann, J T; McEnery, J E; Morgan, T; Mincer, A I; Némethy, P; Pretz, J; Ryan, J M; Parkinson, P M Saz; Shoup, A; Sinnis, G; Smith, A J; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

2009-01-01T23:59:59.000Z

124

The structure of a Mesozoic basin beneath the Lake Tana area, Ethiopia, revealed by magnetotelluric imaging  

E-Print Network [OSTI]

The structure of a Mesozoic basin beneath the Lake Tana area, Ethiopia, revealed by magnetotelluric of Mines, Addis Ababa, Ethiopia c Geological Survey of Ethiopia, Addis Ababa, Ethiopia Received 18 April 2006 Abstract The northwestern Plateau of Ethiopia is almost entirely covered with extensive Tertiary

125

Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars  

E-Print Network [OSTI]

We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and gamma-ray bands. Our unique data set has allowed us to demonstrate that the selection method strongly influences the results, producing biases that cannot be ignored. Almost all the BL Lac objects have been detected by Fermi-LAT, whereas ~40% of the flat-spectrum radio quasars (FSRQs) in the radio, soft X-ray, and hard X-ray selected samples are still below the gamma-ray detection limit even after integrating 27 months of Fermi-LAT data. The radio to sub-mm spectral slope of blazars is quite flat up to ~70GHz, above which it steepens to ~-0.65. BL Lacs have significantly flatter spectra than FSRQs at higher frequencies. The distribution of the rest-frame synchrotron peak frequency (\

Giommi, P; Lahteenmaki, A; Thompson, D J; Capalbi, M; Cutini, S; Gasparrini, D; Gonzalez-Nuevo, J; Leon-Tavares, J; Lopez-Caniego, M; Mazziotta, M N; Monte, C; Perri, M; Raino, S; Tosti, G; Tramacere, A; Verrecchia, F; Aller, H D; Aller, M F; Angelakis, E; Bastieri, D; Berdyugin, A; Bonaldi, A; Bonavera, L; Burigana, C; Burrows, D N; Buson, S; Cavazzuti, E; Chincarini, G; Colafrancesco, S; Costamante, L; Cuttaia, F; D'Ammando, F; de Zotti, G; Frailis, M; Fuhrmann, L; Galeotta, S; Gargano, F; Gehrels, N; Giglietto, N; Giordano, F; Giroletti, M; Keihanen, E; King, O; Krichbaum, T P; Lasenby, A; Lavonen, N; Lawrence, C R; Leto, C; Lindfors, E; Mandolesi, N; Massardi, M; Max-Moerbeck, W; Michelson, P F; Mingaliev, M; Natoli, P; Nestoras, I; Nieppola, E; Nilsson, K; Partridge, B; Pavlidou, V; Pearson, T J; Procopio, P; Rachen, J P; Readhead, A; Reeves, R; Reimer, A; Reinthal, R; Ricciardi, S; Richards, J; Riquelme, D; Saarinen, J; Sajina, A; Sandri, M; Savolainen, P; Sievers, A; Sillanpaa, A; Sotnikova, Y; Stevenson, M; Tagliaferri, G; Takalo, L; Tammi, J; Tavagnacco, D; Terenzi, L; Toffolatti, L; Tornikoski, M; Trigilio, C; Turunen, M; Umana, G; Ungerechts, H; Villa, F; Wu, J; Zacchei, A; Zensus, J A; Zhou, X

2011-01-01T23:59:59.000Z

126

Emergent quantum criticality, Fermi surfaces, and AdS{sub 2}  

SciTech Connect (OSTI)

Gravity solutions dual to d-dimensional field theories at finite charge density have a near-horizon region, which is AdS{sub 2}xR{sup d-1}. The scale invariance of the AdS{sub 2} region implies that at low energies the dual field theory exhibits emergent quantum critical behavior controlled by a (0+1)-dimensional conformal field theories (CFT). This interpretation sheds light on recently-discovered holographic descriptions of Fermi surfaces, allowing an analytic understanding of their low-energy excitations. For example, the scaling behavior near the Fermi surfaces is determined by conformal dimensions in the emergent IR CFT. In particular, when the operator is marginal in the IR CFT, the corresponding spectral function is precisely of the ''marginal Fermi liquid'' form, postulated to describe the optimally doped cuprates.

Faulkner, Thomas; Liu Hong; Vegh, David [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); McGreevy, John [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); KITP, Santa Barbara, California 93106 (United States)

2011-06-15T23:59:59.000Z

127

2FHL: The second Catalog of hard {\\it Fermi}-LAT sources  

E-Print Network [OSTI]

The {\\it Fermi} Large Area Telescope (LAT) has been routinely gathering science data since August 2008, surveying the full sky every three hours. The first Fermi-LAT catalog of sources detected above 10 GeV (1FHL) relied on three years of data to characterize the $>$10 GeV sky. The improved acceptance and point-spread function of the new Pass 8 event reconstruction and classification together with six years of observations now available allow the detection and characterization of sources directly above 50 GeV. This closes the gap between ground-based Cherenkov telescopes, which have excellent sensitivity but small fields of view and short duty cycles, and all-sky observations at GeV energies from orbit. In this contribution we present the second catalog of hard Fermi-LAT sources detected at $>$50\\,GeV.

Ajello, M; Gasparrini, D; Cutini, S

2015-01-01T23:59:59.000Z

128

Quantum mechanics in phase space: First order comparison between the Wigner and the Fermi function  

E-Print Network [OSTI]

The Fermi g_F(x,p) function provides a phase space description of quantum mechanics conceptually different from that based on the the Wigner function W(x,p). In this paper, we show that for a peaked wave packet the g_F(x,p)=0 curve approximately corresponds to a phase space contour level of the Wigner function and provides a satisfactory description of the wave packet's size and shape. Our results show that the Fermi function is an interesting tool to investigate quantum fluctuations in the semiclassical regime.

G. Benenti; G. Strini

2009-09-08T23:59:59.000Z

129

Natural orbits of atomic Cooper pairs in a nonuniform Fermi gas  

E-Print Network [OSTI]

We examine the basic mode structure of atomic Cooper pairs in an inhomogeneous Fermi gas. Based on the properties of Bogoliubov quasi-particle vacuum, the single particle density matrix and the anomalous density matrix share the same set of eigenfunctions. These eigenfunctions correspond to natural pairing orbits associated with the BCS ground state. We investigate these orbits for a Fermi gas in a spherical harmonic trap, and construct the wave function of a Cooper pair in the form of Schmidt decomposition. The issue of spatial quantum entanglement between constituent atoms in a pair is addressed.

Y. H. Pong; C. K. Law

2006-05-08T23:59:59.000Z

130

The Search for Dark Matter with the Fermi Gamma Ray Space Telescope  

SciTech Connect (OSTI)

The Fermi Gamma-Ray Space Telescope has been scanning the gamma ray sky since it was launched by NASA in June 2008 and has a mission lifetime goal of 10 years. Largely due to our particle physics heritage, one of the main physics topics being studied by the Fermi LAT Collaboration is the search for dark matter via indirect detection. My talk will review the progress of these studies, something on how the LAT detector enables them, and expectations for the future. I will discuss both gamma-ray and (electron + positron) searches for dark matter, and some resulting theoretical implications.

Bloom, Elliott (SLAC) [SLAC

2011-03-30T23:59:59.000Z

131

The Enrico Fermi Award Homepage | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 Industrial CarbonArticlesHuman ResourcesScienceHome The Enrico Fermi Award Fermi

132

Sensitivity of the FERMI Detectors to Gamma-Ray Bursts from Evaporating Primordial Black Holes (PBHs)  

E-Print Network [OSTI]

Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. The Fermi Gamma-ray Space Telescope observatory offers increased sensitivity to the gamma-ray bursts produced by PBHs with an initial mass of $\\sim 5\\times 10^{14}$ g expiring today. PBHs are candidate progenitors of unidentified Gamma-Ray Bursts (GRBs) that lack X-ray afterglow. We propose spectral lag, which is the temporal delay between the high and low energy pulses, as an efficient method to identify PBH evaporation events with the Fermi Large Area Telescope (LAT).

T. N. Ukwatta; Jane H. MacGibbon; W. C. Parke; K. S. Dhuga; S. Rhodes; A. Eskandarian; N. Gehrels; L. Maximon; D. C. Morris

2010-03-23T23:59:59.000Z

133

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High EnergyEliane SJuly 2007Fermi NationalFermi

134

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadoreConnecticut Regions National Science2 FusionSCGF Home »FermiFermi

135

Reveal  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromisingStories »Submitter Resources AmesRetirement1

136

2009 Fermi Symposium, Washington, D.C., Nov. 2-5 1 Photon dispersion in causal sets  

E-Print Network [OSTI]

of light may be observable in Fermi time- and energy-tagged data on variable sources, such as gamma-ray by the Fermi Gamma Ray Space Telescope [1]. The expectation from general considerations [2] is that the scale bursts (GRB) and active galactic nuclei (AGN). We describe a method to compute the size of this effect

Simić, Slobodan N.

137

Quasiparticle spectrum and dynamical stability of an atomic Bose-Einstein condensate coupled to a degenerate Fermi gas  

E-Print Network [OSTI]

The quasiparticle excitations and dynamical stability of an atomic Bose-Einstein condensate coupled to a quantum degenerate Fermi gas of atoms at zero temperature is studied. The Fermi gas is assumed to be either in the normal state or to have undergone a phase transition to a superfluid state by forming Cooper pairs. The quasiparticle excitations of the Bose-Einstein condensate exhibit a dynamical instability due to a resonant exchange of energy and momentum with quasiparticle excitations of the Fermi gas. The stability regime for the bosons depends on whether the Fermi gas is in the normal state or in the superfluid state. We show that the energy gap in the quasiparticle spectrum for the superfluid state stabilizes the low energy energy excitations of the condensate. In the stable regime, we calculate the boson quasiparticle spectrum, which is modified by the fluctuations in the density of the Fermi gas.

C. P. Search; H. Pu; W. Zhang; P. Meystre

2001-12-20T23:59:59.000Z

138

Detection of significant cm to sub-mm band radio and gamma-ray correlated variability in Fermi bright blazars  

E-Print Network [OSTI]

The exact location of the gamma-ray emitting region in blazars is still controversial. In order to attack this problem we present first results of a cross-correlation analysis between radio (11 cm to 0.8 mm wavelength, F-GAMMA program) and gamma-ray (0.1-300 GeV) ~ 3.5 year light curves of 54 Fermi-bright blazars. We perform a source stacking analysis and estimate significances and chance correlations using mixed source correlations. Our results reveal: (i) the first highly significant multi-band radio and gamma-ray correlations (radio lagging gamma rays) when averaging over the whole sample, (ii) average time delays (source frame: 76+/-23 to 7+/-9 days), systematically decreasing from cm to mm/sub-mm bands with a frequency dependence tau_r,gamma (nu) ~ nu^-1, in good agreement with jet opacity dominated by synchrotron self-absorption, (iii) a bulk gamma-ray production region typically located within/upstream of the 3 mm core region (tau_3mm,gamma=12+/-8 days), (iv) mean distances between the region of gamma-...

Fuhrmann, L; Chiang, J; Angelakis, E; Zensus, J A; Nestoras, I; Krichbaum, T P; Ungerechts, H; Sievers, A; Pavlidou, V; Readhead, A C S; Max-Moerbeck, W; Pearson, T J

2014-01-01T23:59:59.000Z

139

Suzaku Observation of the Fermi Cygnus Cocoon: Search for a Signature of Young Cosmic-Ray Electrons  

E-Print Network [OSTI]

The origin of Galactic cosmic rays remains unconfirmed, but promising candidates for their sources are found in star-forming regions. We report a series of X-ray observations, with Suzaku, toward the nearby star-forming region of Cygnus X. They aim at comparing diffuse X-ray emissions on and off the $\\gamma$-ray cocoon of hard cosmic rays revealed by Fermi LAT. After excluding point sources and small-scale structures and subtracting the non-X-ray and cosmic X-ray backgrounds, the 2--10~keV X-ray intensity distribution is found to monotonically decrease with increasing Galactic latitude. This indicates that most of the extended emission detected by Suzaku originates from the Galactic ridge. In two observations, we derive upper limits of $3.4 \\times 10^{-8}~{\\rm erg~s^{-1}~cm^{-2}~sr^{-1}}$ and $1.3 \\times 10^{-8}~{\\rm erg~s^{-1}~cm^{-2}~sr^{-1}}$ to X-ray emission in the 2--10 keV range from the gamma-ray cocoon. These limits exclude the presence of cosmic-ray electrons with energies above about 50 TeV at a fl...

Mizuno, T; Takahashi, H; Hayashi, K; Yamazaki, R; Grenier, I; Tibaldo, L

2015-01-01T23:59:59.000Z

140

ccsd00001419, Coherence and correlation properties of a one-dimensional attractive Fermi gas  

E-Print Network [OSTI]

-dimensional attractive Fermi gas Iacopo Carusotto 1, 2 and Yvan Castin 1, #3; 1 Laboratoire Kastler Brossel, #19; Ecole approaches. The crossover to a condensate of pairs can be identi#12;ed as the #12;rst-order pair coherence atomic samples at temperatures well below the degeneracy temperature [1]. This suggests that atomic gases

Note: This page contains sample records for the topic "fermi reveals entire" 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

Fermi-level tuning of topological insulator thin films Masaki Aitani,1  

E-Print Network [OSTI]

Fermi-level tuning of topological insulator thin films Masaki Aitani,1 Yusuke Sakamoto,1 Toru Topological insulators are insulating materials but have metallic edge states with peculiar prop- erties properties of topological insulator ultrathin Bi2Te3 films by angle-resolved photoemission spectroscopy

Hasegawa, Shuji

142

Implementation of an iterative technique for a solution of the Thomas-Fermi equation  

E-Print Network [OSTI]

to Nonlinear Differential and Integral Equations, Dover, New York, 1962. 6. E. Fermi, Un metodo statistico par la determinazione de alcume proprieta dell' atome, Rend. Accad. Naz. del Lincei. cl. sci, fis. , mat. e nat. , 6 (1927), 602-607. 7. F...

Flagg, Raymond Calvert

1978-01-01T23:59:59.000Z

143

Logarithmic Fermi-liquid breakdown in NbFe2 M. Brando,1,  

E-Print Network [OSTI]

temperature dependence of the Sommerfeld coefficient = C/T of the specific heat capacity, C, over nearly two temperature dependences of the resistivity and of the heat capacity over extended ranges in temperatureLogarithmic Fermi-liquid breakdown in NbFe2 M. Brando,1, W. J. Duncan,1 D. Moroni-Klementowicz,1 C

Paris-Sud XI, Université de

144

Fermi National Accelerator Laboratory FERMILAB-Pub-99/354-E  

E-Print Network [OSTI]

Fermi National Accelerator Laboratory FERMILAB-Pub-99/354-E D0 The Isolated Photon Cross Section Purposes. #12;Fermilab-Pub-99 354-E The Isolated Photon Cross Section in pp Collisions at ps = 1.8 TeV B

145

Refining the associations of the Fermi Large Area Telescope Source Catalogs  

E-Print Network [OSTI]

The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) was released in February 2010 and the Fermi-LAT 2-Year Source Catalog (2FGL) appeared in April 2012, based on data from 24 months of operation. Since their releases, many follow up observations of unidentified gamma-ray sources (UGSs) were performed and new procedures to associate gamma-ray sources with potential counterparts at other wavelengths were developed. Here we review and characterize all the associations as published in the 1FGL and 2FGL catalog on the basis of multifrequency archival observations. In particular we located 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition we present new spectroscopic observations of 8 gamma-ray blazar candidates. Based on our investigations, we introduce a new counterpart category of "candidate associations" and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. We compare the 1FGL-assigned coun...

Massaro, F; Landoni, M; Paggi, A; Masetti, N; Giroletti, M; Otí-Floranes, H; Chavushyan, V; Jiménez-Bailón, E; Patińo-Álvarez, V; Digel, S W; Smith, Howard A; Tosti, G

2015-01-01T23:59:59.000Z

146

Extending the Fermi-LAT Data Processing Pipeline to the Grid  

E-Print Network [OSTI]

The Data Handling Pipeline ("Pipeline") has been developed for the Fermi Gamma-Ray Space Telescope (Fermi) Large Area Telescope (LAT) which launched in June 2008. Since then it has been in use to completely automate the production of data quality monitoring quantities, reconstruction and routine analysis of all data received from the satellite and to deliver science products to the collaboration and the Fermi Science Support Center. Aside from the reconstruction of raw data from the satellite (Level 1), data reprocessing and various event-level analyses are also reasonably heavy loads on the pipeline and computing resources. These other loads, unlike Level 1, can run continuously for weeks or months at a time. In addition it receives heavy use in performing production Monte Carlo tasks. The software comprises web-services that allow online monitoring and provides charts summarizing work flow aspects and performance information. The server supports communication with several batch systems such as LSF and BQS and recently also Sun Grid Engine and Condor. This is accomplished through dedicated job control services that for Fermi are running at SLAC and the other computing site involved in this large scale framework, the Lyon computing center of IN2P3. While being different in the logic of a task, we evaluate a separate interface to the Dirac system in order to communicate with EGI sites to utilize Grid resources, using dedicated Grid optimized systems rather than developing our own. (abstract abridged)

Stephan Zimmer; Luisa Arrabito; Tom Glanzman; Tony Johnson; Claudia Lavalley; Andrei Tsaregorodtsev

2012-12-17T23:59:59.000Z

147

The Fermi And Gamov-Teller {beta}-Decay Excitations Of The Scissors Mode 1+ States  

SciTech Connect (OSTI)

In this study, the allowed Gamov-Teller (GT) and Fermi {beta} transitions from 1+-state of the odd-odd nuclei to 1+-states are considered. Calculation of the {beta} transition matrix elements is performed in the phonon description and an analytical expressions for MF and MGT matrix elements are obtained for the first time.

Yildirm, Z.; Ertugral, F.; Kuliev, A. A. [Sakarya University, Physics Department, Adapazari (Turkey); Guliyev, E. [Institute of Physics, National Academy of Sciences, Baku (Azerbaijan)

2007-04-23T23:59:59.000Z

148

Thermodynamical approaches to efficient sympathetic cooling in ultracold Fermi-Bose atomic mixtures  

E-Print Network [OSTI]

mainly due to fundamental obstacles in adapting cooling techniques successfully used for bosonic species degeneracy. This issue has been circumvented by developing two cooling techniques, namely mutual evaporativeThermodynamical approaches to efficient sympathetic cooling in ultracold Fermi-Bose atomic mixtures

Presilla, Carlo

149

Large Fermi energy modulation in graphene transistors with high-pressure O{sub 2}-annealed Y{sub 2}O{sub 3} topgate insulators  

SciTech Connect (OSTI)

We demonstrate a considerable suppression of the low-field leakage through a Y{sub 2}O{sub 3} topgate insulator on graphene by applying high-pressure O{sub 2} at 100?atm during post-deposition annealing (HP-PDA). Consequently, the quantum capacitance measurement for the monolayer graphene reveals the largest Fermi energy modulation (E{sub F}?=??0.52?eV, i.e., the carrier density of ?2?×?10{sup 13}?cm{sup ?2}) in the solid-state topgate insulators reported so far. HP-PDA is the robust method to improve the electrical quality of high-k insulators on graphene.

Kanayama, Kaoru; Nagashio, Kosuke, E-mail: nagashio@material.t.u-tokyo.ac.jp; Nishimura, Tomonori; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2014-02-24T23:59:59.000Z

150

NREL researchers are the first to use a high-performance com-puting tool for a large-eddy simulation of an entire wind plant.  

E-Print Network [OSTI]

Denmark and Sweden and compared results with more than a year's worth of plant data.The simulated power at least 50% wastepaper, including 10% post consumer waste. NREL Develops Simulations forWind Plant Power-eddy simulation of an entire wind plant. Researchers at the National Renewable Energy Laboratory's (NREL) National

151

24th European Photovoltaic Solar Energy Conference, Hamburg, Germany, Sept. 2009 HIGLY PREDICTIVE MODELLING OF ENTIRE SI SOLAR CELLS FOR INDUSTRIAL APPLICATIONS  

E-Print Network [OSTI]

On leave from: Institute for Solar Energy Systems, Sun Yat-Sen University, 510006, Guangzhou, China24th European Photovoltaic Solar Energy Conference, Hamburg, Germany, Sept. 2009 1 HIGLY PREDICTIVE MODELLING OF ENTIRE SI SOLAR CELLS FOR INDUSTRIAL APPLICATIONS P.P. Altermatt,1,2 S. Steingrube,1,2 Y. Yang

152

Abstract--This paper revisits the possibility of controlling the power system entirely by means of price signals. It expands on  

E-Print Network [OSTI]

Abstract-- This paper revisits the possibility of controlling the power system entirely by means, be made to work with some caveats. Index Terms--Power system control, pricing, market design. I. An important extension of the work of Schweppe was provided by William Hogan, who in 1992 introduced

153

Quantum criticality and universal scaling of strongly attractive spin-imbalanced Fermi gases in a one-dimensional harmonic trap  

SciTech Connect (OSTI)

We investigate quantum criticality and universal scaling of strongly attractive Fermi gases confined in a one-dimensional harmonic trap. We demonstrate from the power-law scaling of the thermodynamic properties that current experiments on this system are capable of measuring universal features at quantum criticality, such as universal scaling and Tomonaga-Luttinger liquid physics. The results also provide insights on recent measurements of key features of the phase diagram of a spin-imbalanced atomic Fermi gas [Y. Liao et al., Nature (London) 467, 567 (2010)] and point to further study of quantum critical phenomena in ultracold atomic Fermi gases.

Yin Xiangguo; Chen Shu [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Guan Xiwen [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Batchelor, Murray T. [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Mathematical Sciences Institute, Australian National University, Canberra ACT 0200 (Australia)

2011-07-15T23:59:59.000Z

154

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

SciTech Connect (OSTI)

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

Dugger, Leanna; Profumo, Stefano [Department of Astronomy and Department of Physics, University of California Berkeley, 601 Campbell Hall, Berkeley, CA (United States); Jeltema, Tesla E., E-mail: greentee01@gmail.com, E-mail: tesla@ucolick.org, E-mail: profumo@scipp.ucsc.edu [UCO/Lick Observatories, 1156 High St., Santa Cruz, CA 95064 (United States)

2010-12-01T23:59:59.000Z

155

On the energy-momentum spectrum of a homogeneous Fermi gas  

E-Print Network [OSTI]

We consider translation invariant quantum systems in thermodynamic limit. We argue that their energy-momentum spectra should have shapes consistent with effective models involving quasiparticles. Our main example is second quantized homogeneous interacting Fermi gas in a large cubic box with periodic boundary conditions, at zero temperature. We expect that its energy-momentum spectrum has a positive energy gap and a positive critical velocity.

Jan Derezi?ski; Krzysztof A. Meissner; Marcin Napiórkowski

2012-06-01T23:59:59.000Z

156

Hybrid Monte Carlo with Wilson Dirac operator on the Fermi GPU  

E-Print Network [OSTI]

In this article we present our implementation of a Hybrid Monte Carlo algorithm for Lattice Gauge Theory using two degenerate flavours of Wilson-Dirac fermions on a Fermi GPU. We find that using registers instead of global memory speeds up the code by almost an order of magnitude. To map the array variables to scalars, so that the compiler puts them in the registers, we use code generators. Our final program is more than 10 times faster than a generic single CPU.

Abhijit Chakrabarty; Pushan Majumdar

2012-07-10T23:59:59.000Z

157

Hybrid Monte Carlo with Wilson Dirac operator on the Fermi GPU  

E-Print Network [OSTI]

In this article we present our implementation of a Hybrid Monte Carlo algorithm for Lattice Gauge Theory using two degenerate flavours of Wilson-Dirac fermions on a Fermi GPU. We find that using registers instead of global memory speeds up the code by almost an order of magnitude. To map the array variables to scalars, so that the compiler puts them in the registers, we use code generators. Our final program is more than 10 times faster than a generic single CPU.

Chakrabarty, Abhijit

2012-01-01T23:59:59.000Z

158

Spectral zeta function and non-perturbative effects in ABJM Fermi-gas  

E-Print Network [OSTI]

The exact partition function in ABJM theory on three-sphere can be regarded as a canonical partition function of a non-interacting Fermi-gas with an unconventional Hamiltonian. All the information on the partition function is encoded in the discrete spectrum of this Hamiltonian. We explain how (quantum mechanical) non-perturbative corrections in the Fermi-gas system appear from a spectral consideration. Basic tools in our analysis are a Mellin-Barnes type integral representation and a spectral zeta function. From a consistency with known results, we conjecture that the spectral zeta function in the ABJM Fermi-gas has an infinite number of "non-perturbative" poles, which are invisible in the semi-classical expansion of the Planck constant. We observe that these poles indeed appear after summing up perturbative corrections. As a consequence, the perturbative resummation of the spectral zeta function causes non-perturbative corrections to the grand canonical partition function. We also present another example as...

Hatsuda, Yasuyuki

2015-01-01T23:59:59.000Z

159

{pi} junction and spontaneous current state in a superfluid Fermi gas  

SciTech Connect (OSTI)

We discuss an idea to realize a spontaneous current in a superfluid Fermi gas. When a polarized Fermi superfluid (N{sub {up_arrow}}>N{sub {down_arrow}}, where N{sub {sigma}} is the number of atoms in the hyperfine state described by pseudospin {sigma}={up_arrow},{down_arrow}) is loaded onto a ring-shaped trap with a weak potential barrier, some excess atoms ({Delta}N=N{sub {up_arrow}}-N{sub {down_arrow}}) are localized around the barrier. As shown in our previous paper [T. Kashimura, S. Tsuchiya, and Y. Ohashi, Phys. Rev. A 82, 033617 (2010)], this polarized potential barrier works as a {pi} junction in the sense that the superfluid order parameter changes its sign across the barrier. Because of this, the phase of the superfluid order parameter outside the junction is shown to be twisted by {pi} along the ring, which naturally leads to a circulating supercurrent. While the ordinary supercurrent state is obtained as a metastable state, this spontaneous current state is shown to be more stable than the case with no current. Our results indicate that localized excess atoms would be useful for the manipulation of the superfluid order parameter in cold Fermi gases.

Kashimura, Takashi [Department of Physics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Tsuchiya, Shunji [Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); CREST (JST), 4-1-8 Honcho, Saitama 332-0012 (Japan); Ohashi, Yoji [Department of Physics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); CREST (JST), 4-1-8 Honcho, Saitama 332-0012 (Japan)

2011-07-15T23:59:59.000Z

160

New pulsars detected in gamma-rays with the Fermi-LAT  

E-Print Network [OSTI]

The Fermi Large Area Telescope (LAT) is a powerful pulsar detector, as demonstrated by the over one hundred objects in its second catalog of pulsars. Pass 8 is a new reconstruction and event selection strategy developed by the Fermi-LAT collaboration. Due to the increased acceptance at low energy, Pass 8 improves the pulsation detection sensitivity. Ten new pulsars rise above the 5 sigma threshold and are presented in this work, as well as one previously seen with the former Pass 7 reconstruction. More than 60$\\%$ of the known pulsars with spin-down power ($\\dot{E}$) greater than $10^{36}$ erg/s show pulsations in gamma-rays, as seen with the Fermi Large Area Telescope. Many non-detections of these energetic pulsars are thought to be a consequence of a high background level, or a large distance leading to a flux below the sensitivity limit of the instrument. The gamma-ray beams of the others probably miss the Earth. The new Pass 8 data now allows the detection of gamma ray pulsations from three of these high ...

Laffon, H; Guillemot, L

2015-01-01T23:59:59.000Z

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161

Analytical thermodynamics of a strongly attractive three-component Fermi gas in one dimension  

SciTech Connect (OSTI)

Ultracold three-component atomic Fermi gases in one dimension are expected to exhibit rich physics due to the presence of trions and different pairing states. Quantum phase transitions from the trion state into a paired phase and a normal Fermi liquid occur at zero temperature. We derive the analytical thermodynamics of strongly attractive three-component one-dimensional fermions with SU(3) symmetry via the thermodynamic Bethe ansatz method in unequal Zeeman splitting fields H{sub 1} and H{sub 2}. We find explicitly that for low temperature the system acts like either a two-component or a three-component Tomonaga-Luttinger liquid dependent on the system parameters. The phase diagrams for the chemical potential and specific heat are presented for illustrative values of the Zeeman splitting. We also demonstrate that crossover between different Tomonaga-Luttinger-liquid phases exhibit singular behavior in specific heat and entropy as the temperature tends to zero. Beyond Tomonaga-Luttinger-liquid physics, we obtain the equation of state which provides a precise description of universal thermodynamics and quantum criticality in three-component, strongly attractive Fermi gases.

He Peng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Yin Xiangguo; Wang Yupeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Guan Xiwen [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Batchelor, Murray T. [Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Mathematical Sciences Institute, Australian National University, Canberra ACT 0200 (Australia)

2010-11-15T23:59:59.000Z

162

MILAGRO OBSERVATIONS OF MULTI-TeV EMISSION FROM GALACTIC SOURCES IN THE FERMI BRIGHT SOURCE LIST  

SciTech Connect (OSTI)

We present the result of a search of the Milagro sky map for spatial correlations with sources from a subset of the recent Fermi Bright Source List (BSL). The BSL consists of the 205 most significant sources detected above 100 MeV by the Fermi Large Area Telescope. We select sources based on their categorization in the BSL, taking all confirmed or possible Galactic sources in the field of view of Milagro. Of the 34 Fermi sources selected, 14 are observed by Milagro at a significance of 3 standard deviations or more. We conduct this search with a new analysis which employs newly optimized gamma-hadron separation and utilizes the full eight-year Milagro data set. Milagro is sensitive to gamma rays with energy from 1 to 100 TeV with a peak sensitivity from 10 to 50 TeV depending on the source spectrum and declination. These results extend the observation of these sources far above the Fermi energy band. With the new analysis and additional data, multi-TeV emission is definitively observed associated with the Fermi pulsar, J2229.0+6114, in the Boomerang pulsar wind nebula (PWN). Furthermore, an extended region of multi-TeV emission is associated with the Fermi pulsar, J0634.0+1745, the Geminga pulsar.

Abdo, A. A.; Linnemann, J. T. [Department of Physics and Astronomy, Michigan State University, 3245 BioMedical Physical Sciences Building, East Lansing, MI 48824 (United States); Allen, B. T.; Chen, C. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Aune, T. [Santa Cruz Institute for Particle Physics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Berley, D.; Goodman, J. A. [Department of Physics, University of Maryland, College Park, MD 20742 (United States); Christopher, G. E.; Kolterman, B. E.; Mincer, A. I.; Nemethy, P. [Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); DeYoung, T. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Dingus, B. L.; Hoffman, C. M. [Group P-23, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Ellsworth, R. W. [Department of Physics and Astronomy, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Gonzalez, M. M. [Instituto de AstronomIa, Universidad Nacional Autonoma de Mexico, 04510 Mexico, D.F. (Mexico); Hays, E.; McEnery, J. E. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Huentemeyer, P. H. [Department of Physics, University of Utah, Salt Lake City, UT 84112 (United States); Morgan, T. [Department of Physics, University of New Hampshire, Morse Hall, Durham, NH 03824 (United States)] (and others)

2009-08-01T23:59:59.000Z

163

Determining the Appropriate Package and Transportation Methodology for the Detroit Edison, Fermi II Msrs and Associated Components  

SciTech Connect (OSTI)

During the spring of 2005, Detroit Edison, Enrico Fermi II Nuclear Power Station (Fermi) decided to disposition two MSRs and associated components scheduled for replacement in the spring of 2006 during the MSR Replacement Outage. Of concern to Fermi was the proper packaging and transportation methodology when dis-positioning a component measuring approximately 110' in length and 13' in diameter and weighing over 300 tons. Upon removal from the Turbine Deck the retired MSRs and associated components were turned over to the Rad Waste Group for packaging and final disposition. Fermi requested quotations from vendors to package, transport, and disposition the MSRs and associated components. However, multiple Vendors informed Fermi that the size and weight of the MSRs were questionable in passing permitting requirements and would require segmentation and volume reduction on site or at a waste processor. Fermi contracted with MHF Logistical Solutions (MHF-LS) based on their ability to receive clearances for shipping the MSRs in one piece via two heavy haul rail conveyances acting as a bolstered load with professionally engineered blocking and bracing configured to support the retired MSRs. (authors)

Weber, B. [Detroit Edison Company/Enrico Fermi II Nuclear Power Station, Newport, MI (United States); Dempsey, S. [MHF Logistical Solutions, Oak Ridge, TN (United States)

2007-07-01T23:59:59.000Z

164

Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission  

SciTech Connect (OSTI)

We report on a detailed investigation of the {gamma}-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reported detections of 3C 120 and 3C 111 in the GeV photon energy range; a detailed look at the temporal characteristics of the observed {gamma}-ray emission reveals in addition possible flux variability in both sources. No statistically significant {gamma}-ray detection of the other BLRGs was however found in the considered dataset. Though the sample size studied is small, what appears to differentiate 3C 111 and 3C 120 from the BLRGs not yet detected in {gamma}-rays is the particularly strong nuclear radio flux. This finding, together with the indications of the {gamma}-ray flux variability and a number of other arguments presented, indicate that the GeV emission of BLRGs is most likely dominated by the beamed radiation of relativistic jets observed at intermediate viewing angles. In this paper we also analyzed a comparison sample of high accretion-rate Seyfert 1 galaxies, which can be considered radio-quiet counterparts of BLRGs, and found none were detected in {gamma}-rays. A simple phenomenological hybrid model applied for the broad-band emission of the discussed radio-loud and radio-quiet type 1 active galaxies suggests that the relative contribution of the nuclear jets to the accreting matter is {ge} 1% on average for BLRGs, while {le} 0.1% for Seyfert 1 galaxies.

Kataoka, J.; /Waseda U., RISE; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.; Takahashi, Y.; /Waseda U., RISE; Cheung, C.C.; /Natl. Acad. Sci. /Naval Research Lab, Wash., D.C.; Hayashida, M.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; Grandi, P.; /Bologna Observ.; Burnett, T.H.; /Washington U., Seattle; Celotti, A.; /SISSA, Trieste; Fegan, S.J.; Fortin, P.; /Ecole Polytechnique; Maeda, K.; Nakamori, T.; /Waseda U., RISE; Taylor, G.B.; /New Mexico U.; Tosti, G.; /INFN, Perugia /Perugia U.; Digel, S.W.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; McConville, W.; /NASA, Goddard /Maryland U.; Finke, J.; /Naval Research Lab, Wash., D.C.; D'Ammando, F.; /IASF, Palermo /INAF, Rome

2012-06-07T23:59:59.000Z

165

approaches reveal single: Topics by E-print Network  

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

of the Large Area Telescope (LAT) on board the Fermi spacecraft in June 2008, the number of observed gamma-ray pulsars has increased dramatically. A large number of these are...

166

Gravity-analogy in one-dimensional ideal Fermi fluids and Burgers' equation  

E-Print Network [OSTI]

An hydrodynamic description of a one-dimensional flow of an ideal Fermi fluid is constructed from a semiclassical approximation. For an initially fully degenerate fluid, Euler and continuity hydrodynamic equations are dual to two uncoupled inviscid Burgers' equations. Yet the price for the initial simplicity of the description is paid by the complexity of non-linear instabilities towards possible turbulent evolutions. Nevertheless, it is shown that linear long-wavelength density perturbations on a stationary flow are generically stable. Consequently, linear sound obeys a wave equation with analogy to gravity. The results have applications for ultra-cold atomic gases.

Stefano Giovanazzi

2010-10-14T23:59:59.000Z

167

Superallowed Fermi transitions in RPA with a relativistic point-coupling energy functional  

E-Print Network [OSTI]

The self-consistent random phase approximation (RPA) approach with the residual interaction derived from a relativistic point-coupling energy functional is applied to evaluate the isospin symmetry-breaking corrections {\\delta}c for the 0+\\to0+ superallowed Fermi transitions. With these {\\delta}c values, together with the available experimental ft values and the improved radiative corrections, the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix is examined. Even with the consideration of uncertainty, the sum of squared top-row elements has been shown to deviate from the unitarity condition by 0.1% for all the employed relativistic energy functionals.

Z. X. Li; J. M. Yao; H. Chen

2011-04-11T23:59:59.000Z

168

Nuclear symmetry energy from the Fermi-energy difference in nuclei  

E-Print Network [OSTI]

The neutron-proton Fermi-energy difference and the correlation to nucleon separation energies for some magic nuclei are investigated with the Skyrme energy density functionals and nuclear masses, with which the nuclear symmetry energy at sub-saturation densities is constrained from 54 Skyrme parameter sets. The extracted nuclear symmetry energy at sub-saturation density of 0.11 fm$^{-3}$ is 26.2 $\\pm$ 1.0 MeV with 1.5 $\\sigma$ uncertainty. By further combining the neutron-skin thickness of 208Pb, ten Skyrme forces with slope parameter of 28energy around saturation densities.

Ning Wang; Li Ou; Min Liu

2013-03-15T23:59:59.000Z

169

Superscaling in Nuclei: A Search for Scaling Function Beyond the Relativistic Fermi Gas Model  

E-Print Network [OSTI]

We construct a scaling function $f(\\psi^{\\prime})$ for inclusive electron scattering from nuclei within the Coherent Density Fluctuation Model (CDFM). The latter is a natural extension to finite nuclei of the Relativistic Fermi Gas (RFG) model within which the scaling variable $\\psi^{\\prime}$ was introduced by Donnelly and collaborators. The calculations show that the high-momentum components of the nucleon momentum distribution in the CDFM and their similarity for different nuclei lead to quantitative description of the superscaling in nuclei. The results are in good agreement with the experimental data for different transfer momenta showing superscaling for negative values of $\\psi^{\\prime}$, including those smaller than -1.

A. N. Antonov; M. K. Gaidarov; D. N. Kadrev; M. V. Ivanov; E. Moya de Guerra; J. M. Udias

2004-02-25T23:59:59.000Z

170

Quantum lattice gas model of Fermi systems with relativistic energy relations  

E-Print Network [OSTI]

Presented are several example quantum computing representations of quantum systems with a relativistic energy relation. Basic unitary representations of free Dirac particles and BCS superconductivity are given. Then, these are combined into a novel unitary representation of a Fermi condensate superfluid. The modeling approach employs an operator splitting method that is an analytically closed-form product decomposition of the unitary evolution operator, applied in the high-energy limit. This allows the relativistic wave equations to be cast as unitary finite-difference equations. The split evolution operators (comprising separate kinetic and interaction energy evolution terms) serve as quantum lattice gas models useful for efficient quantum simulation.

Jeffrey Yepez

2013-07-12T23:59:59.000Z

171

Superscaling and Neutral Current Quasielastic Neutrino-Nucleus Scattering beyond the Relativistic Fermi Gas Model  

E-Print Network [OSTI]

The superscaling analysis is extended to include quasielastic (QE) scattering via the weak neutral current of neutrinos and antineutrinos from nuclei. The scaling function obtained within the coherent density fluctuation model (used previously in calculations of QE inclusive electron and charge-changing (CC) neutrino scattering) is applied to neutral current neutrino and antineutrino scattering with energies of 1 GeV from $^{12}$C with a proton and neutron knockout (u-channel inclusive processes). The results are compared with those obtained using the scaling function from the relativistic Fermi gas model and the scaling function as determined from the superscaling analysis (SuSA) of QE electron scattering.

A. N. Antonov; M. V. Ivanov; M. B. Barbaro; J. A. Caballero; E. Moya de Guerra; M. K. Gaidarov

2007-06-01T23:59:59.000Z

172

Techniques for targeted Fermi-GBM follow-up of gravitational-wave events  

E-Print Network [OSTI]

The Advanced LIGO and Advanced Virgo ground-based gravitational-wave detectors are projected to come online 2015-2016, reaching a final sensitivity sufficient to observe dozens of binary neutron star mergers per year by 2018. We present a fully-automated, targeted search strategy for prompt gamma-ray counterparts in offline Fermi-GBM data. The multi-detector method makes use of a detailed model response of the instrument, and benefits from time and sky location information derived from the gravitational-wave signal.

Lindy Blackburn; Michael S. Briggs; Jordan Camp; Nelson Christensen; Valerie Connaughton; Peter Jenke; John Veitch

2013-05-14T23:59:59.000Z

173

The Life of Enrico Fermi | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 Industrial CarbonArticlesHuman ResourcesScienceHome The Enrico Fermi AwardThe Life

174

Fermi Site Office CX Determinations | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 Industrial CarbonArticlesHumanJuneDocumentingFermi Site Office CX Determinations

175

2011 Annual Planning Summary for Fermi Site Office (FSO) | Department of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment( Sample of0225145750414.pdfDepartment ofMachinesEnergy Fermi

176

Iltt: Fermi National Accelerator Laboratory FERMILAB-Pub-75/44-THY  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. |Endecaheme c-Type|Iltt: Fermi National Accelerator

177

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High EnergyEliane SJuly 2007Fermi National

178

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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179

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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180

Fermi National Accelerator Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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181

Fermi LARGE AREA TELESCOPE DETECTION OF TWO VERY-HIGH-ENERGY (E > 100 GeV) ?-RAY PHOTONS FROM THE z = 1.1 BLAZAR PKS 0426–380  

SciTech Connect (OSTI)

We report the Fermi Large Area Telescope (LAT) detection of two very-high-energy (VHE, E > 100 GeV) ?-ray photons from the directional vicinity of the distant (redshift, z = 1.1) blazar PKS 0426–380. The null hypothesis that both the 134 and 122 GeV photons originate from unrelated sources can be rejected at the 5.5? confidence level. We therefore claim that at least one of the two VHE photons is securely associated with PKS 0426–380, making it the most distant VHE emitter known to date. The results are in agreement with recent Fermi-LAT constraints on the extragalactic background light (EBL) intensity, which imply a z ? 1 horizon for ? 100 GeV photons. The LAT detection of the two VHE ?-rays coincided roughly with flaring states of the source, although we did not find an exact correspondence between the VHE photon arrival times and the flux maxima at lower ?-ray energies. Modeling the ?-ray continuum of PKS 0426–380 with daily bins revealed a significant spectral hardening around the time of the first VHE event detection (LAT photon index ? ? 1.4) but on the other hand no pronounced spectral changes near the detection time of the second one. This combination implies a rather complex variability pattern of the source in ?-rays during the flaring epochs. An additional flat component is possibly present above several tens of GeV in the EBL-corrected Fermi-LAT spectrum accumulated over the ?8 month high state.

Tanaka, Y. T.; Mizuno, T. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Cheung, C. C.; Dermer, C. D. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States)] [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Inoue, Y. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)] [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Stawarz, ?. [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States)] [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Wood, D. L. [Praxis Inc., Alexandria, VA 22303 (United States)] [Praxis Inc., Alexandria, VA 22303 (United States); Chekhtman, A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States)] [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Fukazawa, Y.; Ohno, M. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Paneque, D. [Max-Planck-Institut für Physik, D-80805 München (Germany)] [Max-Planck-Institut für Physik, D-80805 München (Germany); Thompson, D. J., E-mail: ytanaka@hep01.hepl.hiroshima-u.ac.jp [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-11-01T23:59:59.000Z

182

Fermi Observations  

Office of Scientific and Technical Information (OSTI)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: Crystal structureComposite--FOR IMMEDIATE RELEASEEmissionsi

183

Spectral Studies of Flaring FSRQs at GeV Energies Using Pass 8 Fermi-LAT Data  

E-Print Network [OSTI]

Flat spectrum radio quasars (FSRQs) are bright active galactic nuclei surrounded by gas clouds within a UV-visible intense radiation field that form the so-called broad line region (BLR). These objects emit relativistic jets from a region close to the central supermassive black hole and through the BLR. The Fermi-Large Area Telescope (Fermi-LAT) is sensitive to gamma-ray photons from $\\sim$30 MeV to more than 300 GeV. We have performed spectral analysis of bright FSRQs in a 5.5 year (2008-2014) data sample collected by Fermi-LAT, using the new Pass 8 event selection and instrument response function. Also, our study of flaring episodes in a limited time range brings interesting results while compared to the full 5.5 year data samples.

Britto, Richard J G; Lott, Benoît

2015-01-01T23:59:59.000Z

184

Elastic constants and Fermi surface topology change in Calaverite AuTe{sub 2}: A density functional study  

SciTech Connect (OSTI)

Structural, elastic, electronic and Fermi surface studies of AuTe{sub 2} have been carried out by means of first principles calculations based on density functional theory. The calculated ground state properties agree well with the experiment. Fermi surface and elastic constants are predicted for the first time and from the calculated elastic constants we find the compound to be mechanically stable satisfying the stability criteria of monoclinic structure. In addition, we also find the c-axis to be more compressible than the other two which is also speculated from the present work. The metallic behaviour of this compound is confirmed from the electronic band structure calculation as we find the bands to cross the Fermi level (E{sub F}). In addition, we also observe a FS topology change under pressure which is also explained in the present work.

Gudelli, Vijay Kumar, E-mail: kanchana@iith.ac.in; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh (India)

2014-04-24T23:59:59.000Z

185

On-Shell Mediators and Top-Charm Dark Matter Models for the Fermi-LAT Galactic Center Excess  

E-Print Network [OSTI]

An excess in gamma-rays from the galactic center observed by the Fermi Large Area Telescope has been proposed as a possible signal of dark matter annihilation. Recently, the Fermi collaboration showed that systematic errors broaden the range of spectral shapes for this excess. We demonstrate fits to this range for (1) flavor-violating annihilations to top-charm pairs and (2) annihilations to on-shell bosonic mediators which decay to Standard Model quarks in a boosted frame. Annihilation of 40 - 100 GeV DM to pairs of spin-1 mediators provide a good fit to the Fermi-LAT spectrum with a normalization consistent with a thermal relic. Top-charm modes and annihilation to three pseudoscalar mediators can fit the spectral shape but typically require non-thermal annihilation cross sections.

Rajaraman, Arvind; Tanedo, Philip

2015-01-01T23:59:59.000Z

186

THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS  

SciTech Connect (OSTI)

This catalog summarizes 117 high-confidence ?0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

Abdo, A. A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Allafort, A.; Bloom, E. D.; Bottacini, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Universitŕ di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Belfiore, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bhattacharyya, B. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Universitŕ di Trieste, I-34127 Trieste (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M., E-mail: hartog@stanford.edu [Dipartimento di Fisica ''M. Merlin'' dell'Universitŕ e del Politecnico di Bari, I-70126 Bari (Italy); and others

2013-10-01T23:59:59.000Z

187

The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope  

E-Print Network [OSTI]

The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected with a test statistic (TS) greater than 25, using the first 4 years of data. The 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\\deg}), which is a 71% increase over the second catalog that was based on 2 years of data. There are 28 duplicate associations (two counterparts to the same gamma-ray source), thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. A very large majority of these AGNs (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their spectral properties, these sources are evenly split between FSRQs and BL~Lacs. The general properties of the 3LAC sample confirm previous findings from earlier catalogs, but some new subclasses (e.g., ...

Ackermann, M; Atwood, W; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Gonzalez, J; Bellazzini, R; Bissaldi, E; Blandford, R; Bloom, E; Bonino, R; Bottacini, E; Brandt, T; Bregeon, J; Britto, R; Bruel, P; Buehler, R; Buson, S; Caliandro, G; Cameron, R; Caragiulo, M; Caraveo, P; Casandjian, J; Cavazzuti, E; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L; Conrad, J; Cutini, S; D'Abrusco, R; D'Ammando, F; Angelis, A; Desiante, R; Digel, S; Venere, L; Drell, P; Favuzzi, C; Fegan, S; Ferrara, E; Finke, J; Focke, W; Franckowiak, A; Fuhrmann, L; Furniss, A; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I; Grove, J; Guiriec, S; Hewitt, J W; Hill, A; Horan, D; J'ohannesson, G; Johnson, A; Johnson, W; Kataoka, J; Kuss, M; Mura, G; Larsson, S; Latronico, L; Leto, C; Li, J; Li, L; Longo, F; Loparco, F; Lott, B; Lovellette, M; Lubrano, P; Madejski, G; Mayer, M; Mazziotta, M; McEnery, J; Michelson, P; Mizuno, T; Moiseev, A; Monzani, M; Morselli, A; Moskalenko, I; Murgia, S; Nuss, E; Ohno, M; Ohsugi, T; Ojha, R; Omodei, N; Orienti, M; Orlando, E; Paggi, A; Paneque, D; Perkins, J; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T; Rain`o, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Romani, R; Salvetti, D; Schaal, M; Schinzel, F; Schulz, A; Sgr`o, C; Siskind, E; Sokolovsky, K; Spada, F; Spandre, G; Spinelli, P; Stawarz, L; Suson, D; Takahashi, H; Takahashi, T; Tanaka, Y; Thayer, J; Thayer, J; Tibaldo, L; Torres, D; Torresi, E; Tosti, G; Troja, E; Uchiyama, Y; Vianello, G; Winer, B; Wood, K; Zimmer, S

2015-01-01T23:59:59.000Z

188

The Fermi blazars' divide based on the diagnostic of the SEDs peak frequencies  

E-Print Network [OSTI]

We have studied the quasi-simultaneous Spectral Energy Distributions (SED) of 48 LBAS blazars, detected within the three months of the LAT Bright AGN Sample (LBAS) data taking period, combining Fermi and Swift data with radio NIR-Optical and hard-X/gamma-ray data. Using these quasi-simultaneous SEDs, sampling both the low and the high energy peak of the blazars broad band emission, we were able to apply a diagnostic tool based on the estimate of the peak frequencies of the synchrotron (S) and Inverse Compton (IC) components. Our analysis shows a Fermi blazars' divide based on the peak frequencies of the SED. The robust result is that the Synchrotron Self Compton (SSC) region divides in two the plane were we plot the peak frequency of the synchrotron SED vs the typical Lorentz factor of the electrons most contributing to the synchrotron emission and to the inverse Compton process. Objects within or below this region, radiating likely via the SSC process, are high-frequency-peaked BL Lac object (HBL), or low/in...

Tramacere, A; Giommi, P; Mazziotta, N; Monte, C

2010-01-01T23:59:59.000Z

189

Localization of Gamma-Ray Bursts using the Fermi Gamma-Ray Burst Monitor  

E-Print Network [OSTI]

The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 Gamma-Ray Bursts (GRBs) since it began science operations in July, 2008. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope, INTEGRAL, and MAXI, or through triangulations from the InterPlanetary Network (IPN), to analyze the accuracy of GBM GRB localizations. We find that the reported statistical uncertainties on GBM localizations, which can be as small as 1 degree, underestimate the distance of the GBM positions to the true GRB locations and we attribute this to systematic uncertainties. The distribution of systematic uncertainties is well represented (68% confidence level) by a 3.7 degree Gaussian with a non-Gaussian tail that contains about 10% of GBM-detected GRBs and extends to approximately 14 degrees. A more complex model suggests that there is a dependence of the systematic uncertainty on the position of the GRB in spacecraft coordinates, with GRBs in the quadrants on the Y-axis better l...

Connaughton, V; Goldstein, A; Meegan, C A; Paciesas, W S; Preece, R D; Wilson-Hodge, C A; Gibby, M H; Greiner, J; Gruber, D; Jenke, P; Kippen, R M; Pelassa, V; Xiong, S; Yu, H -F; Bhat, P N; Burgess, J M; Byrne, D; Fitzpatrick, G; Foley, S; Giles, M M; Guiriec, S; van der Horst, A J; von Kienlin, A; McBreen, S; McGlynn, S; Tierney, D; Zhang, B -B

2014-01-01T23:59:59.000Z

190

VERITAS OBSERVATIONS OF SIX BRIGHT, HARD-SPECTRUM FERMI-LAT BLAZARS  

SciTech Connect (OSTI)

We report on VERITAS very high energy (VHE; E {>=} 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV upper limits are presented, along with contemporaneous Fermi observations and non-concurrent Swift UVOT and X-Ray Telescope data. The blazar broadband spectral energy distributions (SEDs) are assembled and modeled with a single-zone synchrotron self-Compton model. The SED built for each of the six blazars shows a synchrotron peak bordering between the intermediate- and high-spectrum-peak classifications, with four of the six resulting in particle-dominated emission regions.

Aliu, E.; Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T.; Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Boettcher, M. [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Cui, W. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Duke, C. [Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Falcone, A., E-mail: afurniss@ucsc.edu, E-mail: pafortin@cfa.harvard.edu, E-mail: deirdre@llr.in2p3.fr [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Collaboration: VERITAS Collaboration; and others

2012-11-10T23:59:59.000Z

191

ccsd-00000540(version1):1Aug2003 Production of Long-Lived Ultracold Li2 Molecules from a Fermi gas  

E-Print Network [OSTI]

samples, the collapse of Bose-Einstein condensates (BEC) for negative scattering length [4], solitonccsd-00000540(version1):1Aug2003 Production of Long-Lived Ultracold Li2 Molecules from a Fermi gas a degenerate two component Fermi gas by sweeping a magnetic field across a Feshbach resonance. The atom

Paris-Sud XI, Université de

192

The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission  

SciTech Connect (OSTI)

The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view (FoV), high-energy {gamma}-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. The LAT was built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. This paper describes the LAT, its preflight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4 x 4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 (x, y) tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an eight-layer hodoscopic configuration with a total depth of 8.6 radiation lengths, giving both longitudinal and transverse information about the energy deposition pattern. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large FoV (2.4 sr) and ensuring that most pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. Data obtained with the LAT are intended to (1) permit rapid notification of high-energy {gamma}-ray bursts and transients and facilitate monitoring of variable sources, (2) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (3) measure spectra from 20 MeV to more than 50 GeV for several hundred sources, (4) localize point sources to 0.3-2 arcmin, (5) map and obtain spectra of extended sources such as SNRs, molecular clouds, and nearby galaxies, (6) measure the diffuse isotropic {gamma}-ray background up to TeV energies, and (7) explore the discovery space for dark matter.

Atwood, W.B.; /UC, Santa Cruz; Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Anderson, B. /UC, Santa Cruz; Axelsson, M.; /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bartelt, J.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bederede, D.; /DAPNIA, Saclay; Bellardi, F.; /INFN, Pisa; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bignami, G.F.; /Pavia U.; Bisello, D.; /INFN, Padua /Padua U.; Bissaldi, E.; /Garching, Max Planck Inst., MPE; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Pisa /INFN, Pisa /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /INFN, Padua /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /Kalmar U. /Royal Inst. Tech., Stockholm /DAPNIA, Saclay /ASI, Rome /INFN, Pisa /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors.; ,

2009-05-15T23:59:59.000Z

193

Observations of MilkyWay Dwarf Spheroidal galaxies with the Fermi-LAT detector and  

SciTech Connect (OSTI)

We report on the observations of 14 dwarf spheroidal galaxies with the Fermi Gamma-Ray Space Telescope taken during the first 11 months of survey mode operations. The Fermi telescope, which is conducting an all-sky {gamma}-ray survey in the 20 MeV to >300 GeV energy range, provides a new opportunity to test particle dark matter models through the expected {gamma}-ray emission produced by pair annihilation of weakly interacting massive particles (WIMPs). Local Group dwarf spheroidal galaxies, the largest galactic substructures predicted by the cold dark matter scenario, are attractive targets for such indirect searches for dark matter because they are nearby and among the most extreme dark matter dominated environments. No significant {gamma}-ray emission was detected above 100 MeV from the candidate dwarf galaxies. We determine upper limits to the {gamma}-ray flux assuming both power-law spectra and representative spectra from WIMP annihilation. The resulting integral flux above 100 MeV is constrained to be at a level below around 10{sup -9} photons cm{sup -2}s{sup -1}. Using recent stellar kinematic data, the {gamma}-ray flux limits are combined with improved determinations of the dark matter density profile in 8 of the 14 candidate dwarfs to place limits on the pair annihilation cross-section ofWIMPs in several widely studied extensions of the standard model, including its supersymmetric extension and other models that received recent attention. With the present data, we are able to rule out large parts of the parameter space where the thermal relic density is below the observed cosmological dark matter density and WIMPs (neutralinos here) are dominantly produced non-thermally, e.g. in models where supersymmetry breaking occurs via anomaly mediation. The {gamma}-ray limits presented here also constrain some WIMP models proposed to explain the Fermi and PAMELA e{sup +}e{sup -} data, including low-mass wino-like neutralinos and models with TeV masses pair-annihilating into muon-antimuon pairs.

Abdo, A.A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T.H.; Buson, S.; Caliandro, G.A.; /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC /UC, Santa Cruz /INFN, Pisa /DAPNIA, Saclay /INFN, Trieste /Trieste U. /INFN, Padua /Padua U. /INFN, Perugia /Perugia U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /IASF, Milan /George Mason U. /NASA, Goddard

2010-05-26T23:59:59.000Z

194

Importance of the Fermi-surface topology to the superconducting state of the electron-doped pnictide Ba(Fe1-xCox)?As?  

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

We used angle-resolved photoemission spectroscopy and thermoelectric power to study the poorly explored, highly overdoped side of the phase diagram of Ba(Fe1-xCox)?As? high-temperature superconductor. Our data demonstrate that several Lifshitz transitions—topological changes of the Fermi surface—occur for large x. The central hole barrel changes to ellipsoids that are centered at Z at x~0.11 and subsequently disappear around x~0.2; changes in thermoelectric power occur at similar x values. Tc decreases and goes to zero around x~0.15—between the two Lifshitz transitions. Beyond x=0.2 the central pocket becomes electron-like and superconductivity does not exist. Our observations reveal the importance of the underlying Fermiology in electron-doped iron arsenides. We speculate that a likely necessary condition for superconductivity in these materials is the presence of the central hole pockets rather than nesting between central and corner pockets.

Liu, Chang; Palczewski, A. D.; Dhaka, R. S.; Kondo, Takeshi; Fernandes, R. M.; Mun, E. D.; Hodovanets, H.; Thaler, A. N.; Schmalian, J.; Bud’ko, S. L.; Canfield, P. C.; Kaminski, A.

2011-07-01T23:59:59.000Z

195

ccsd-00001419,version1-5Apr2004 Coherence and correlation properties of a one-dimensional attractive Fermi gas  

E-Print Network [OSTI]

-dimensional attractive Fermi gas Iacopo Carusotto1, 2 and Yvan Castin1, 1 Laboratoire Kastler Brossel, ´Ecole Normale to a condensate of pairs can be identified as the first-order pair coherence extending throughout the whole size of neutral atoms have opened the way to the realization of fermionic atomic samples at temperatures well

Paris-Sud XI, Université de

196

Condition on the KohnSham kinetic energy and modern parametrization of the ThomasFermi density  

E-Print Network [OSTI]

; published online 20 January 2009 We study the asymptotic expansion of the neutral-atom energy as the atomic-correlation energy, EXC n , must be approximated. But a direct, orbital-free DFT could be constructed if onlyCondition on the Kohn­Sham kinetic energy and modern parametrization of the Thomas­Fermi density

Burke, Kieron

197

Dipole oscillations in Bose-Fermi mixtures in the time-dependent Gross-Pitaevskii and Vlasov equations  

E-Print Network [OSTI]

Dipole oscillations in Bose-Fermi mixtures in the time-dependent Gross-Pitaevskii and Vlasov equations Tomoyuki Maruyama1,2,3 and George F. Bertsch1 1 Institute for Nuclear Theory, University with the time-dependent Gross-Pitaevskii equation and the Vlasov equation. While the Bose gas oscillates

Bertsch George F.

198

The Needle in the 100 deg2 Haystack: Uncovering Afterglows of Fermi GRBs with the Palomar Transient Factory  

E-Print Network [OSTI]

The Fermi Gamma-Ray Space Telescope has greatly expanded the number and energy window of observations of gamma-ray bursts (GRBs). However, the coarse localizations of tens to a hundred square degrees provided by the Fermi Gamma-ray Burst Monitor (GBM) instrument have posed a formidable obstacle to locating the bursts' host galaxies, measuring their redshifts, and tracking their panchromatic afterglows. We have built a target of opportunity mode for the intermediate Palomar Transient Factory (iPTF) in order to perform targeted searches for Fermi afterglows. Here, we present the results of one year of this program: eight afterglow discoveries, two of which (GRBs 130702A and 140606B) were at low redshift (z=0.145 and 0.384 respectively) and had spectroscopically confirmed broad-line type Ic supernovae. We present our broadband follow-up including spectroscopy as well as X-ray, UV, optical, millimeter, and radio observations. We study possible selection effects in the context of the total Fermi and Swift GRB samp...

Singer, Leo P; Cenko, S Bradley; Perley, Daniel A; Anderson, Gemma E; Anupama, G C; Arcavi, Iair; Bhalerao, Varun; Bue, Brian D; Cao, Yi; Connaughton, Valerie; Corsi, Alessandra; Cucchiara, Antonino; Fender, Rob P; Fox, Derek B; Gehrels, Neil; Goldstein, Adam; Gorosabel, J; Horesh, Assaf; Hurley, Kevin; Johansson, Joel; Kann, D A; Kouveliotou, Chryssa; Huang, Kuiyun; Kulkarni, S R; Masci, Frank; Nugent, Peter; Rau, Arne; Rebbapragada, Umaa D; Staley, Tim D; Svinkin, Dmitry; Thöne, C C; Postigo, A de Ugarte; Urata, Yuji; Weinstein, Alan

2015-01-01T23:59:59.000Z

199

The Luttinger model: its role in the RG--theory of one dimensional many body Fermi systems  

E-Print Network [OSTI]

to the investigations of the mathe­ matical properties of Condensed Matter Physics. This paper reviews aspects functions of the ground state of a spin 0 Fermi gas can be identified, to leading non trivial order x+ t ! k) a \\Sigma k;! (1:5) I do not repeat here the heuristic analysis showing that taking the two

200

Nonlocal extension of the dispersive-optical-model to describe data below the Fermi energy  

E-Print Network [OSTI]

Present applications of the dispersive-optical-model analysis are restricted by the use of a local but energy-dependent version of the generalized Hartree-Fock potential. This restriction is lifted by the introduction of a corresponding nonlocal potential without explicit energy dependence. Such a strategy allows for a complete determination of the nucleon propagator below the Fermi energy with access to the expectation value of one-body operators (like the charge density), the one-body density matrix with associated natural orbits, and complete spectral functions for removal strength. The present formulation of the dispersive optical model (DOM) therefore allows the use of elastic electron-scattering data in determining its parameters. Application to ${}^{40}$Ca demonstrates that a fit to the charge radius leads to too much charge near the origin using the conventional assumptions of the functional form of the DOM. A corresponding incomplete description of high-momentum components is identified, suggesting t...

Dickhoff, W H; Waldecker, S J; Charity, R J; Sobotka, L G

2010-01-01T23:59:59.000Z

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201

Evolution from BCS to BEC Superfluidity in p-Wave Fermi Gases  

SciTech Connect (OSTI)

We consider the evolution of superfluid properties of a three-dimensional p-wave Fermi gas from a weak coupling Bardeen-Cooper-Schrieffer (BCS) to strong coupling Bose-Einstein condensation (BEC) limit as a function of scattering volume. At zero temperature, we show that a quantum phase transition occurs for p-wave systems, unlike the s-wave case where the BCS to BEC evolution is just a crossover. Near the critical temperature, we derive a time-dependent Ginzburg-Landau (GL) theory and show that the GL coherence length is generally anisotropic due to the p-wave nature of the order parameter, and becomes isotropic only in the BEC limit.

Iskin, M.; Melo, C.A.R. sa de [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2006-02-03T23:59:59.000Z

202

Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems  

E-Print Network [OSTI]

We report experimental signals of Bose-Einstein condensation in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4$\\pi$ detector array to the forward angle VAMOS magnetic spectrometer, allowed us to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. Furthermore, by means of quantum fluctuation analysis techniques, temperatures and mean volumes per particle "as seen by" bosons and fermions separately are correlated to the excitation energy of the reconstructed system. The obtained results are consistent with the production of dilute mixed (bosons/fermions) systems, where bosons experience a smaller volume as compared to the surrounding fermionic gas. Our findings recall similar phenomena observed in the study of boson condensates in atomic traps.

P. Marini; H. Zheng; M. Boisjoli; G. Verde; A. Chbihi; G. Ademard; L. Auger; C. Bhattacharya; B. Borderie; R. Bougault; J. Frankland; E. Galichet; D. Gruyer; S. Kundu; M. La Commara; I. Lombardo; O. Lopez; G. Mukherjee; P. Napolitani; M. Parlog; M. F. Rivet; E. Rosato; R. Roy; G. Spadaccini; M. Vigilante; P. C. Wigg; A. Bonasera

2015-01-03T23:59:59.000Z

203

Testing dissipative magnetosphere model light curves and spectra with FERMI pulsars  

E-Print Network [OSTI]

We explore the emission properties of a dissipative pulsar magnetosphere model introduced by Kalapotharakos et al. (2014), comparing its high energy light curves and spectra, due to curvature radiation, with data collected by the Fermi LAT. The magnetosphere structure is assumed to be near the force-free solution. The accelerating electric field, inside the light-cylinder, is assumed to be negligible, while outside the light-cylinder it rescales with a finite conductivity ({\\sigma}). In our approach we calculate the corresponding high energy emission by integrating the trajectories of test particles that originate from the stellar surface, taking into account both the accelerating electric field components and the radiation reaction forces. First we explore the parameter space assuming different value sets for the stellar magnetic field, stellar period, and conductivity. We show that the general properties of the model are in a good agreement with observed emission characteristics of young {\\gamma}-ray pulsar...

Brambilla, Gabriele; Harding, Alice K; Kazanas, Demosthenes

2015-01-01T23:59:59.000Z

204

Fermi Orbital Derivatives in Self-Interaction Corrected Density Functional Theory: Applications to Closed Shell Atoms  

E-Print Network [OSTI]

A recent modification of the Perdew-Zunger self-interaction-correction (SIC) to the density-functional formalism (Pederson, Ruzsinszky, Perdew) has provided a framework for explicitly restoring unitary invariance to the expression for the total energy. The formalism depends upon construction of Lowdin orthonormalized Fermi-orbitals (Luken et al) which parametrically depend on variational quasi-classical electronic positions. Derivatives of these quasi-classical electronic positions, required for efficient minimization of the self-interaction corrected energy, are derived and tested here on atoms. Total energies and ionization energies in closed-shell atoms, where correlation is less important, using the PW92 LDA functional are in very good to excellent agreement with experiment and non-relativistic Quantum-Monte-Carlo (QMC) results.

Mark R. Pederson

2014-12-13T23:59:59.000Z

205

Bose and Fermi gases in the early Universe with self-gravitational effect  

SciTech Connect (OSTI)

We study the self-gravitational effect on the equation of state (EoS) of Bose and Fermi gases in thermal equilibrium at the end of reheating, the period after quark-hadron transition and before big bang nucleosynthesis (BBN). After introducing new grand canonical partition functions based on the work of Uhlenbeck and Gropper, we notice some interesting features of the newly developed EoSs with distinct behaviors of relativistic and nonrelativistic gases under self-gravity. The usual negligence of the self-gravitational effect when solving the background expansion of the early Universe is justified with numerical results, showing the magnitude of the self-gravitational modification of the state constant to be less than O(10{sup -78}). This helps us to clarify the background thermal evolution of the primordial patch. Such clarification is crucial in testing gravity theories, evaluating inflation models and determining element abundances in BBN.

Niu Yuezhen; Huang Junwu; Ma Boqiang [School of Physics and State Keye Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China) and Center for High Energy Physics, Peking University, Beijing 100871 (China) and Center for History and Philosophy of Science, Peking University, Beijing 100871 (China)

2011-03-15T23:59:59.000Z

206

From fermions to the Fermi paradox: a fertile cosmos fit for life?  

E-Print Network [OSTI]

Paradoxes usually hint at gaps in our understanding. The resolution of Fermi's may require knowledge common to extraterrestrials accounting for a convergence in their cosmological outlook. What would a universe optimised for conscious lifeforms be like? Perhaps extraterrestrials would reply ours. How preposterous: life is rare, survival is a struggle, red giants purge orbiting planets of inhabitants, baryons only account for a small fraction of the universe and otherwise habitable planets orbiting the longest-lived stars are tidally locked. Think again: following a preliminary stelliferous era (~400Gyr) during which numerous planets with subsurface oceans form from the ejecta of type Ia supernovae and colonists are recruited, the universe might comfortably support colossal numbers of skilfully crafted aquatic lifeforms in uncrowded conditions for ~10^23 years. Fermionic dark matter could serve as the fuel, slowly annihilating within planets containing pressurised iron. Semiconductors can explore the proposal ...

Spivey, R J

2011-01-01T23:59:59.000Z

207

Braid group representations and cold Fermi gases in the fast pairing regime  

E-Print Network [OSTI]

It is widely recognized that the main difficulty in designing devices which could process information using quantum states is due to the decoherence of local excitations about a ground state. A solution to this problem was suggested in \\cite{Kitaev}, relying on (non-local) topological excitations, structurally protected against local noise. However, a practical implementation of this proposal using special Landau levels in fractional quantum Hall effect systems (FQHE) \\cite{QHE} has proven elusive, while accessible FQHE states are theoretically not optimal because their representations in the Hilbert space of states are not dense. We propose using a different physical system (cold Fermi atoms), whose semiclassical dynamics is described by a hyperelliptic function in the Sklyanin formalism. The homological structure of the complex curve corresponds to representations of the braid group, with the action of Hecke operators leading to singularities detectable in the semiclassical oscillations. We argue that, for ...

Hotalen, Bryan

2015-01-01T23:59:59.000Z

208

Holographic Thermalization, stability of AdS, and the Fermi-Pasta-Ulam-Tsingou paradox  

E-Print Network [OSTI]

For a real massless scalar field in general relativity with a negative cosmological constant, we uncover a large class of spherically symmetric initial conditions that are close to AdS, but whose numerical evolution does not result in black hole formation. According to the AdS/CFT dictionary, these bulk solutions are dual to states of a strongly interacting boundary CFT that fail to thermalize at late times. Furthermore, as these states are not stationary, they define dynamical CFT configurations that do not equilibrate. We develop a two-timescale perturbative formalism that captures both direct and inverse cascades of energy and agrees with our fully nonlinear evolutions in the appropriate regime. We also show that this formalism admits a large class of quasi-periodic solutions. Finally, we demonstrate a striking parallel between the dynamics of AdS and the classic Fermi-Pasta-Ulam-Tsingou problem.

Venkat Balasubramanian; Alex Buchel; Stephen R. Green; Luis Lehner; Steven L. Liebling

2014-06-16T23:59:59.000Z

209

Fermi Limit on the Neutrino Flux from Gamma-ray Bursts  

E-Print Network [OSTI]

If gamma-ray bursts (GRBs) produce high energy cosmic rays, neutrinos are expected to be generated in GRBs due to photo-pion productions. However we stress that the same process also generates electromagnetic (EM) emission induced by the production of secondary electrons and photons, and that the EM emission is expected to be correlated to the neutrino flux. Using the Fermi/LAT observational results on gamma-ray flux from GRBs, the GRB neutrino emission is limited to be below ~20 GeV/m^2 per GRB event on average, which is independent of the unknown GRB proton luminosity. This neutrino limit suggests that the full IceCube needs stacking more than 130 GRBs in order to detect one GRB muon neutrino.

Zhuo Li

2013-06-14T23:59:59.000Z

210

Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems  

E-Print Network [OSTI]

We report experimental signals of Bose-Einstein condensation in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4$\\pi$ detector array to the forward angle VAMOS magnetic spectrometer, allowed us to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. Furthermore, by means of quantum fluctuation analysis techniques, temperatures and mean volumes per particle "as seen by" bosons and fermions separately are correlated to the excitation energy of the reconstructed system. The obtained results are consistent with the production of dilute mixed (bosons/fermions) systems, where bosons experience a smaller volume as compared to the surrounding fermionic gas. Our findings recall similar phenomena observed in the study of boson condensates in atomic traps.

Marini, P; Boisjoli, M; Verde, G; Chbihi, A; Ademard, G; Auger, L; Bhattacharya, C; Borderie, B; Bougault, R; Frankland, J; Galichet, E; Gruyer, D; Kundu, S; La Commara, M; Lombardo, I; Lopez, O; Mukherjee, G; Napolitani, P; Parlog, M; Rivet, M F; Rosato, E; Roy, R; Spadaccini, G; Vigilante, M; Wigg, P C; Bonasera, A

2015-01-01T23:59:59.000Z

211

Current Research at the University of Chicago Enrico Fermi Institute and James Franck Institute  

ScienceCinema (OSTI)

These talks will give an overview of physics research at the University of Chicago centered in two research institutes. The Enrico Fermi Institute pursues research in some core areas of the physical sciences. These include cosmology, particle physics, theoretical physics, particle astrophysics, and cosmochemistry. The EFI talk will focus on some examples of these activities which together will provide a broad overview of EFI science. Research at the James Franck Institute centers on the intersection between physics, chemistry and materials science, with the aim to unravel the complex connections between structure and dynamics in condensed matter systems. The JFI is also home to the Chicago Materials Research Science and Engineering Center. The JFI talk will provide highlights of current projects by JFI members.

Simon Swordy

2010-01-08T23:59:59.000Z

212

Spectrometer for X-ray emission experiments at FERMI free-electron-laser  

SciTech Connect (OSTI)

A portable and compact photon spectrometer to be used for photon in-photon out experiments, in particular x-ray emission spectroscopy, is presented. The instrument operates in the 25–800 eV energy range to cover the full emissions of the FEL1 and FEL2 stages of FERMI. The optical design consists of two interchangeable spherical varied-lined-spaced gratings and a CCD detector. Different input sections can be accommodated, with/without an entrance slit and with/without an additional relay mirror, that allow to mount the spectrometer in different end-stations and at variable distances from the target area both at synchrotron and at free-electron-laser beamlines. The characterization on the Gas Phase beamline at ELETTRA Synchrotron (Italy) is presented.

Poletto, L., E-mail: poletto@dei.unipd.it; Frassetto, F.; Miotti, P. [CNR - Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, I-35131 Padova (Italy); Di Cicco, A.; Iesari, F. [Physics Division, School of Science and Technology, Universitŕ di Camerino, I-62032 Camerino (Italy); Finetti, P. [ELETTRA - Sincrotrone Trieste, Basovizza Area Science Park, S. S. 14 - km 163,5, I-34149, Basovizza (TS) (Italy); Grazioli, C. [Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy); CNR-Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, I-34149 Trieste (Italy); Kivimäki, A. [CNR-Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, I-34149 Trieste (Italy); Stagira, S. [Politecnico di Milano – Department of Physics, I-20133 Milano (Italy); Coreno, M. [ELETTRA - Sincrotrone Trieste, Basovizza Area Science Park, S. S. 14 - km 163,5, I-34149, Basovizza (TS) (Italy); CNR – Istituto di Struttura della Materia (CNR-ISM), UOS Basovizza, I-34149 Trieste (Italy)

2014-10-15T23:59:59.000Z

213

Medium effects and the shear viscosity of the dilute Fermi gas away from the conformal limit  

E-Print Network [OSTI]

We study the shear viscosity of a dilute Fermi gas as a function of the scattering length in the vicinity of the unitarity limit. The calculation is based on kinetic theory, which provides a systematic approach to transport properties in the limit in which the fugacity $z=n\\lambda^3/2$ is small. Here, $n$ is the density of the gas and $\\lambda$ is the thermal wave length of the fermions. At leading order in the fugacity expansion the shear viscosity is independent of density, and the minimum shear viscosity is achieved at unitarity. At the next order medium effects modify the scattering amplitude as well as the quasi-particle energy and velocity. We show that these effects shift the minimum of the shear viscosity to the Bose-Einstein condensation (BEC) side of the resonance, in agreement with the result of recent experiments.

Marcus Bluhm; Thomas Schaefer

2014-10-10T23:59:59.000Z

214

FERMI LIMIT ON THE NEUTRINO FLUX FROM GAMMA-RAY BURSTS  

SciTech Connect (OSTI)

If gamma-ray bursts (GRBs) produce high-energy cosmic rays, neutrinos are expected to be generated in GRBs via photo-pion productions. However, we stress that the same process also generates electromagnetic (EM) emission induced by the secondary electrons and photons, and that the EM emission is expected to be correlated with neutrino flux. Using Fermi/Large Area Telescope results on gamma-ray flux from GRBs, the GRB neutrino emission is limited to be <20 GeV m{sup -2} per GRB event on average, which is independent of the unknown GRB proton luminosity. This neutrino limit suggests that IceCube, operating at full scale, requires stacking of more than 130 GRBs in order to detect one GRB muon neutrino.

Li Zhuo [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing (China); Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming (China)

2013-06-20T23:59:59.000Z

215

MAGNETICALLY AND BARYONICALLY DOMINATED PHOTOSPHERIC GAMMA-RAY BURST MODEL FITS TO FERMI-LAT OBSERVATIONS  

SciTech Connect (OSTI)

We consider gamma-ray burst models where the radiation is dominated by a photospheric region providing the MeV Band spectrum, and an external shock region responsible for the GeV radiation via inverse Compton scattering. We parameterize the initial dynamics through an acceleration law {Gamma}{proportional_to}r {sup {mu}}, with {mu} between 1/3 and 1 to represent the range between an extreme magnetically dominated and a baryonically dominated regime, depending also on the magnetic field configuration. We compare these models to several bright Fermi-LAT bursts, and show that both the time-integrated and the time-resolved spectra, where available, can be well described by these models. We discuss the parameters which result from these fits, and discuss the relative merits and shortcomings of the two models.

Veres, Peter; Meszaros, Peter [Department of Astronomy and Astrophysics, Department of Physics, and Center for Particle and Gravitational Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)] [Department of Astronomy and Astrophysics, Department of Physics, and Center for Particle and Gravitational Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Zhang, Bin-Bin, E-mail: veresp@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)] [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

2013-02-10T23:59:59.000Z

216

Enrico Fermi Fast Reactor Spent Nuclear Fuel Criticality Calculations: Degraded Mode  

SciTech Connect (OSTI)

The objective of this calculation is to characterize the nuclear criticality safety concerns associated with the codisposal of the Department of Energy's (DOE) Enrico Fermi (EF) Spent Nuclear Fuel (SNF) in a 5-Defense High-Level Waste (5-DHLW) Waste Package (WP) and placed in a Monitored Geologic Repository (MGR). The scope of this calculation is limited to the determination of the effective neutron multiplication factor (k{sub eff}) for the degraded mode internal configurations of the codisposal WP. The results of this calculation and those of Ref. 8 will be used to evaluate criticality issues and support the analysis that will be performed to demonstrate the viability of the codisposal concept for the Monitored Geologic Repository.

D.R. Moscalu; L. Angers; J. Monroe-Rammsey; H.R. Radulesca

2000-07-21T23:59:59.000Z

217

Finite-Temperature Pairing Gap of a Unitary Fermi Gas by Quantum Monte Carlo Calculations  

SciTech Connect (OSTI)

We calculate the one-body temperature Green's (Matsubara) function of the unitary Fermi gas via quantum Monte Carlo, and extract the spectral weight function A(p,omega) using the methods of maximum entropy and singular value decomposition. From A(p,omega) we determine the quasiparticle spectrum, which can be accurately parametrized by three functions of temperature: an effective mass m*, a mean-field potential U, and a gap DELTA. Below the critical temperature T{sub c}=0.15epsilon{sub F} the results for m*, U, and DELTA can be accurately reproduced using an independent quasiparticle model. We find evidence of a pseudogap in the fermionic excitation spectrum for temperatures up to T*{approx_equal}0.20{epsilon}{sub F}>T{sub c}.

Magierski, Piotr; Wlazlowski, Gabriel [Faculty of Physics, Warsaw University of Technology, ulica Koszykowa 75, 00-662 Warsaw (Poland); Bulgac, Aurel; Drut, Joaquin E. [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

2009-11-20T23:59:59.000Z

218

The Fermi-Pasta-Ulam problem revisited: stochasticity thresholds in nonlinear Hamiltonian systems  

E-Print Network [OSTI]

The Fermi-Pasta-Ulam $\\alpha$-model of harmonic oscillators with cubic anharmonic interactions is studied from a statistical mechanical point of view. Systems of N= 32 to 128 oscillators appear to be large enough to suggest statistical mechanical behavior. A key element has been a comparison of the maximum Lyapounov coefficient $\\lambda_{max}$ of the FPU $\\alpha$-model and that of the Toda lattice. For generic initial conditions, $\\lambda_{max}(t)$ is indistinguishable for the two models up to times that increase with decreasing energy (at fixed N). Then suddenly a bifurcation appears, which can be discussed in relation to the breakup of regular, soliton-like structures. After this bifurcation, the $\\lambda_{max}$ of the FPU model appears to approach a constant, while the $\\lambda_{max}$ of the Toda lattice appears to approach zero, consistent with its integrability. This suggests that for generic initial conditions the FPU $\\alpha$-model is chaotic and will therefore approach equilibrium and equipartition of energy. There is, however, a threshold energy density $\\epsilon_c(N)\\sim 1/N^2$, below which trapping occurs; here the dynamics appears to be regular, soliton-like and the approach to equilibrium - if any - takes longer than observable on any available computer. Above this threshold the system appears to behave in accordance with statistical mechanics, exhibiting an approach to equilibrium in physically reasonable times. The initial conditions chosen by Fermi, Pasta and Ulam were not generic and below threshold and would have required possibly an infinite time to reach equilibrium.

Lapo Casetti; Monica Cerruti-Sola; Marco Pettini; E. G. D. Cohen

1998-04-21T23:59:59.000Z

219

Superfluidity and collective modes in Rashba spin–orbit coupled Fermi gases  

SciTech Connect (OSTI)

We present a theoretical study of the superfluidity and the corresponding collective modes in two-component atomic Fermi gases with s-wave attraction and synthetic Rashba spin–orbit coupling. The general effective action for the collective modes is derived from the functional path integral formalism. By tuning the spin–orbit coupling from weak to strong, the system undergoes a crossover from an ordinary BCS/BEC superfluid to a Bose–Einstein condensate of rashbons. We show that the properties of the superfluid density and the Anderson–Bogoliubov mode manifest this crossover. At large spin–orbit coupling, the superfluid density and the sound velocity become independent of the strength of the s-wave attraction. The two-body interaction among the rashbons is also determined. When a Zeeman field is turned on, the system undergoes quantum phase transitions to some exotic superfluid phases which are topologically nontrivial. For the two-dimensional system, the nonanalyticities of the thermodynamic functions and the sound velocity across the phase transition are related to the bulk gapless fermionic excitation which causes infrared singularities. The superfluid density and the sound velocity behave nonmonotonically: they are suppressed by the Zeeman field in the normal superfluid phase, but get enhanced in the topological superfluid phase. The three-dimensional system is also studied. -- Highlights: •The general effective action for Rashba spin–orbit coupled Fermi superfluids is derived. •The evolution of the collective modes manifests the BCS/BEC-rashbon crossover. •The superfluid properties are universal at large spin–orbit coupling. •The sound velocity behaves nonanalytically across the quantum phase transition.

He, Lianyi, E-mail: lianyi@th.physik.uni-frankfurt.de [Frankfurt Institute for Advanced Studies and Institute for Theoretical Physics, J. W. Goethe University, 60438 Frankfurt am Main (Germany)] [Frankfurt Institute for Advanced Studies and Institute for Theoretical Physics, J. W. Goethe University, 60438 Frankfurt am Main (Germany); Huang, Xu-Guang, E-mail: xhuang@th.physik.uni-frankfurt.de [Center for Exploration of Energy and Matter and Physics Department, Indiana University, Bloomington, IN 47408 (United States)] [Center for Exploration of Energy and Matter and Physics Department, Indiana University, Bloomington, IN 47408 (United States)

2013-10-15T23:59:59.000Z

220

THE LUMINOSITY FUNCTION OF FERMI-DETECTED FLAT-SPECTRUM RADIO QUASARS  

SciTech Connect (OSTI)

Fermi has provided the largest sample of {gamma}-ray-selected blazars to date. In this work we use a complete sample of flat spectrum radio quasars (FSRQs) detected during the first year of operation to determine the luminosity function (LF) and its evolution with cosmic time. The number density of FSRQs grows dramatically up to redshift {approx}0.5-2.0 and declines thereafter. The redshift of the peak in the density is luminosity dependent, with more luminous sources peaking at earlier times; thus the LF of {gamma}-ray FSRQs follows a luminosity-dependent density evolution similar to that of radio-quiet active galactic nuclei. Also, using data from the Swift Burst Alert Telescope we derive the average spectral energy distribution (SED) of FSRQs in the 10 keV-300 GeV band and show that there is no correlation between the luminosity at the peak of the {gamma}-ray emission component and its peak frequency. Using this luminosity-independent SED with the derived LF allows us to predict that the contribution of FSRQs to the Fermi isotropic {gamma}-ray background is 9.3{sup +1.6}{sub -1.0}% ({+-}3% systematic uncertainty) in the 0.1-100 GeV band. Finally we determine the LF of unbeamed FSRQs, finding that FSRQs have an average Lorentz factor of {gamma} = 11.7{sup +3.3}{sub -2.2}, that most are seen within 5 Degree-Sign of the jet axis, and that they represent only {approx}0.1% of the parent population.

Ajello, M.; Shaw, M. S.; Romani, R. W.; Costamante, L.; Reimer, A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Dermer, C. D. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); King, O. G.; Max-Moerbeck, W.; Readhead, A.; Richards, J. L.; Stevenson, M., E-mail: majello@slac.stanford.edu, E-mail: msshaw@stanford.edu, E-mail: rwr@astro.stanford.edu [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

Strong-coupling ansatz for the one-dimensional Fermi gas in a harmonic potential  

E-Print Network [OSTI]

The one-dimensional (1D) Fermi gas with repulsive short-range interactions provides an important model of strong correlations and is often amenable to exact methods. However, in the presence of confinement, no exact solution is known for an arbitrary number of strongly interacting fermions. Here, we propose a novel ansatz for generating the lowest-energy wavefunctions of the repulsive 1D Fermi gas in a harmonic potential near the Tonks-Girardeau (TG) limit of infinite interactions. We specialize to the case of a single impurity interacting with $N$ majority particles, where we may derive analytic forms of the approximate wavefunctions. Comparing with exact numerics, we show that the overlap between the wavefunctions from our ansatz and the exact ones in the ground-state manifold exceeds 0.9997 for $N\\leq8$. Moreover, the overlap for the ground-state wavefunction extrapolates to 0.9999 as $N\\to\\infty$. Thus our ansatz is essentially indistinguishable from numerically exact results in both the few- and many-body limits. In the large $N$ limit, we find that the impurity probability density in the ground state is only slightly perturbed by the infinitely repulsive interactions, while the quasiparticle residue vanishes as the many-body limit is approached, reflecting the Anderson orthogonality catastrophe. We derive an effective Heisenberg spin-chain model for the regime near the TG limit, within which our ansatz is exact. Here, we find that the impurity eigenstates in the spin basis correspond to discrete Chebyshev polynomials. The energy of states in excited manifolds is calculated using a dynamical SO(2,1) symmetry, which provides an exact relation between states related by a scaling transformation. We finally show how our results for the wavefunctions and the energy spectrum can be detected in cold atomic gases via collective-mode, tunneling, and radio-frequency experiments.

Jesper Levinsen; Pietro Massignan; Georg M. Bruun; Meera M. Parish

2014-08-29T23:59:59.000Z

222

Negative Ion Photoelectron Spectroscopy Reveals Thermodynamic...  

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

corresponding value that one water molecule is capable of (ca. 13 kcalmol). Molecular dynamics simulations and quantum chemical calculations reveal the most plausible...

223

Alleviation of fermi-level pinning effect at metal/germanium interface by the insertion of graphene layers  

SciTech Connect (OSTI)

In this paper, we report the alleviation of the Fermi-level pinning on metal/n-germanium (Ge) contact by the insertion of multiple layers of single-layer graphene (SLG) at the metal/n-Ge interface. A decrease in the Schottky barrier height with an increase in the number of inserted SLG layers was observed, which supports the contention that Fermi-level pinning at metal/n-Ge contact originates from the metal-induced gap states at the metal/n-Ge interface. The modulation of Schottky barrier height by varying the number of inserted SLG layers (m) can bring about the use of Ge as the next-generation complementary metal-oxide-semiconductor material. Furthermore, the inserted SLG layers can be used as the tunnel barrier for spin injection into Ge substrate for spin-based transistors.

Baek, Seung-heon Chris; Seo, Yu-Jin; Oh, Joong Gun; Albert Park, Min Gyu; Bong, Jae Hoon; Yoon, Seong Jun; Lee, Seok-Hee, E-mail: seokheelee@ee.kaist.ac.kr [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seo, Minsu; Park, Seung-young [Division of Materials Science, Korea Basic Science Institute (KBSI), 169-148 Daehak-ro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Park, Byong-Guk [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2014-08-18T23:59:59.000Z

224

Determination of Landau Fermi-liquid parameters of strongly interacting fermions by means of a nonlinear scaling transformation  

E-Print Network [OSTI]

A nonlinear transformation approach is formulated for the correlated fermions' thermodynamics through a medium-scaling effective action. An auxiliary implicit variable-effective chemical potential is introduced to characterize the non-Gaussian fluctuations physics. By incorporating the nonlocal correlation effects, the achieved grand partition function is made of coupled highly nonlinear parametric equations. Analytically, the low temperature expansions for the strongly interacting unitary Fermi gas are performed for the adiabatic compressibility-sound speed and specific heat with the Sommerfeld lemma. The expressions for the Landau Fermi-Liquid parameters $F_0^s$ and $F_1^s$ of the strongly interacting fermion system are obtained. As a universal constant, the effective fermion mass ratio is $m^*/m={10/9}$ at unitarity.

Ji-sheng Chen

2009-10-20T23:59:59.000Z

225

Non-thermal emission from Galaxy Clusters and future observations with the FERMI gamma-ray telescope and LOFAR  

E-Print Network [OSTI]

FERMI (formely GLAST) and LOFAR will shortly provide crucial information on the non-thermal components (relativistic particles and magnetic field) in galaxy clusters. After discussing observational facts that already put constraints on the properties and origin of non-thermal components, I will report on the emission spectrum from galaxy clusters as expected in the context of general calculations in which relativistic particles (protons and secondary electrons due to proton-proton collisions) interact with MHD turbulence generated in the cluster volume during cluster-cluster mergers. In this scenario (known as re-acceleration scenario) diffuse cluster-scale radio emission is produced in massive clusters during merging events, while gamma ray emission, at some level, is expected to be common in clusters. Expectations of interest for LOFAR and FERMI are also briefly discussed.

G. Brunetti

2008-10-03T23:59:59.000Z

226

Fermi-LAT Upper Limit for NGC 4151 and its Implications for Physics of Hot Accretion Flow  

E-Print Network [OSTI]

We present preliminary results of our analysis of the {\\it Fermi}-LAT data from the direction of NGC 4151. We find a new gamma-ray source with a statistical significance sigma > 5, shifted by 0.5degr from the position of NGC 4151. Apparently, the source was bright only during a 1.5-year period between December 2011 and June 2013 and it strongly contaminated the signal from NGC 4151. Therefore, we neglect this period in our analysis. We find two additional, persistent gamma-ray sources with high sigma, shifted from NGC 4151 by ~1.5degr and 5degr, whose presence has been recently confirmed in the Third Fermi Catalog. After subtracting the above sources, we still see a weak residual, with sigma ~processes in hot flows as well as the...

Wojaczynski, Rafal; Xie, Fu-Guo

2015-01-01T23:59:59.000Z

227

Revealing Quantum Advantage in a Quantum Network  

E-Print Network [OSTI]

The assumption of source independence was used to reveal nonlocal (apart from standard Bell-CHSH scenario) nature of correlations generated in entanglement swapping experiments. In this work, we have derived a set of sufficient criteria, imposed on the states (produced by the sources) under which source independence can reveal nonbilocal nature of correlations in a quantum network. To show this, we have considered real two qubit X states thereby discussing the various utilities of assuming source independence in a quantum network.

Kaushiki Mukherjee; Biswajit Paul; Debasis Sarkar

2014-10-01T23:59:59.000Z

228

Constituent quark masses obtained from hadron masses with contributions of Fermi-Breit and Glozman-Riska hyperfine interactions  

SciTech Connect (OSTI)

We use the color-spin and flavor-spin interaction Hamiltonians with SU(3) flavor symmetry breaking to obtain meson and baryon mass formulas. Adjusting these masses with experimental masses we determine the constituent quark masses. We discuss the constituent quark masses obtained from meson and baryon mass fits. The results for constituent quark masses are very similar in the case of two different phenomenological models: Fermi-Breit and Glozman-Riska hyperfine interactions.

Borka Jovanovic, V.; Borka, D. [Laboratory of Physics (010), Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Ignjatovic, S. R. [Department of Physics, Faculty of Science, University of Banja Luka, Mladena Stojanovica 2, 78000 Banja Luka (Bosnia and Herzegowina); Jovanovic, P. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia)

2010-12-01T23:59:59.000Z

229

Superscaling and Charge-Changing Neutrino Scattering from Nuclei in the $\\boldsymbol ?$-Region beyond the Relativistic Fermi Gas Model  

E-Print Network [OSTI]

The superscaling analysis using the scaling function obtained within the coherent density fluctuation model is extended to calculate charge-changing neutrino and antineutrino scattering on $^{12}$C at energies from 1 to 2 GeV not only in the quasielastic but also in the delta excitation region. The results are compared with those obtained using the scaling functions from the relativistic Fermi gas model and from the superscaling analysis of inclusive scattering of electrons from nuclei.

M. V. Ivanov; M. B. Barbaro; J. A. Caballero; A. N. Antonov; E. Moya de Guerra; M. K. Gaidarov

2008-02-29T23:59:59.000Z

230

Test of Fermi Gas Model and Plane-Wave Impulse Approximation Against Electron-Nucleus Scattering Data  

E-Print Network [OSTI]

A widely used relativistic Fermi gas model and plane-wave impulse approximation are tested against electron-nucleus scattering data. Inclusive quasi-elastic cross section are calculated and compared with high-precision data for C, O, and Ca. A dependence of agreement between calculated cross section and data on a momentum transfer is shown. Results for the C(nu_mu,mu) reaction are presented and compared with experimental data of the LSND collaboration.

A. V. Butkevich; S. P. Mikheyev

2005-04-30T23:59:59.000Z

231

Distinct Fermi Surface Topology and Nodeless Superconducting Gap in a Tl0:58Rb0:42Fe1:72Se2 Superconductor  

E-Print Network [OSTI]

-based superconductors reported so far. The Fermi surface around the M point shows a nearly isotropic superconducting gap) superconductors [6]. It is important to explore whether the high-Tc superconductiv- ity mechanism in this new FeDistinct Fermi Surface Topology and Nodeless Superconducting Gap in a Ă°Tl0:58Rb0:42Ă?Fe1:72Se2

Tian, Weidong

232

The composition of the Fermi-LAT IGRB intensity: emission from extragalactic point sources and dark matter annihilations  

E-Print Network [OSTI]

A new estimation of the isotropic diffuse gamma-ray background (IGRB) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) has been presented for 50 months of data, in the energy range 100 MeV-820 GeV and for different modelings of the Galactic foreground. We attempt here the interpretation of the Fermi-LAT IGRB data in terms of the gamma-ray unresolved emission from different extragalactic populations. We find very good fits to the experimental IGRB, obtained with theoretical predictions for the emission from active galactic nuclei and star forming galaxies. In addition, we probe a possible emission coming from the annihilation of weakly interacting dark matter (DM) particles in the halo of our Galaxy. We set stringent limits on its annihilation cross section into gamma-rays, which are about the thermal relic value for a wide range of DM masses. We also identify regions in the DM mass and annihilation cross section parameter space which can significantly improve the...

Di Mauro, Mattia

2015-01-01T23:59:59.000Z

233

Revisiting variable gamma-ray sky at 1 GeV with 6 years of Fermi-LAT data  

E-Print Network [OSTI]

We perform a blind search for the variability of the gamma-ray sky in the energy range E>1 GeV using 308 weeks of the Fermi-LAT data. We use the technique based on the comparison of the weekly photon counts and exposures in sky pixels by means of the Kolmogorov-Smirnov test. We consider the flux variations in the region significant if statistical probability of uniformity is less than $4\\times10^{-6}$, which corresponds to 0.05 false detections in the whole set of 12288 pixels. Close inspection of the detected variable regions result in identification of 8 sources without previous known variability. Two of them are included in the second Fermi LAT source catalogue (FBQS J122424.1+243623 and GB6 J0043+3426) and one (3EG J1424+3734) was reported by EGRET and also was included in the First Fermi LAT source catalogue (1FGL), but is missing in the 2FGL. Possible identifications of five other sources are obtained using NED and SIMBAD databases (1RXS J161939.9+765515, PMN J2320-6447, PKS 0226-559, PKS J0030-0211, PM...

Pshirkov, M S

2015-01-01T23:59:59.000Z

234

Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes  

SciTech Connect (OSTI)

The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

Abdo, A.A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; Ajello, M.; /SLAC; Anderson, B.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Bechtol, K.; /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /SLAC; Bregeon, J.; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Padua U. /Naval Research Lab, Wash., D.C. /Udine U. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Pisa /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Udine U. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Bari U. /INFN, Bari /INFN, Pisa /INFN, Bari /NASA, Goddard /Maryland U.; /more authors..

2012-04-11T23:59:59.000Z

235

The Swift/Fermi GRB 080928 from 1 eV to 150 keV  

E-Print Network [OSTI]

We present the results of a comprehensive study of the Gamma-Ray Burst 080928 and of its afterglow. GRB 080928 was a long burst detected by Swift/BAT and Fermi/GBM. It is one of the exceptional cases where optical emission was already detected when the GRB itself was still radiating in the gamma-ray band. For nearly 100 seconds simultaneous optical, X-ray and gamma-ray data provide a coverage of the spectral energy distribution of the transient source from about 1 eV to 150 keV. Here we analyze the prompt emission, constrain its spectral properties, and set lower limits on the initial Lorentz factor of the relativistic outflow. In particular, we show that the SED during the main prompt emission phase is in agreement with synchrotron radiation. We construct the optical/near-infrared light curve and the spectral energy distribution based on Swift/UVOT, ROTSE-IIIa (Australia) and GROND (La Silla) data and compare it to the X-ray light curve retrieved from the Swift/XRT repository. We show that its bumpy shape ca...

Rossi, A; Klose, S; Kann, D A; Rau, A; Krimm, H A; Jóhannesson, G; Panaitescu, A; Yuan, F; Ferrero, P; Krühler, T; Greiner, J; Schady, P; Pandey, S B; Amati, L; Afonso, P M J; Akerlof, C W; Arnold, L; Clemens, C; Filgas, R; Hartmann, D H; Yolda?, A Küpcü; McBreen, S; McKay, T A; Guelbenzu, A Nicuesa; E., F Olivares; Paciesas, B; Rykoff, E S; Szokoly, G; Updike, A C; Yolda?, A

2010-01-01T23:59:59.000Z

236

Nonlocal extension of the dispersive-optical-model to describe data below the Fermi energy  

E-Print Network [OSTI]

Present applications of the dispersive-optical-model analysis are restricted by the use of a local but energy-dependent version of the generalized Hartree-Fock potential. This restriction is lifted by the introduction of a corresponding nonlocal potential without explicit energy dependence. Such a strategy allows for a complete determination of the nucleon propagator below the Fermi energy with access to the expectation value of one-body operators (like the charge density), the one-body density matrix with associated natural orbits, and complete spectral functions for removal strength. The present formulation of the dispersive optical model (DOM) therefore allows the use of elastic electron-scattering data in determining its parameters. Application to ${}^{40}$Ca demonstrates that a fit to the charge radius leads to too much charge near the origin using the conventional assumptions of the functional form of the DOM. A corresponding incomplete description of high-momentum components is identified, suggesting that the DOM formulation must be extended in the future to accommodate such correlations properly. Unlike the local version, the present nonlocal DOM limits the location of the deeply-bound hole states to energies that are consistent with (\\textit{e,e}$^{\\prime}$\\textit{p}) and (\\textit{p,2p}) data.

W. H. Dickhoff; D. Van Neck; S. J. Waldecker; R. J. Charity; L. G. Sobotka

2010-10-07T23:59:59.000Z

237

Reproducing neutrino effects on the matter power spectrum through a degenerate Fermi gas approach  

E-Print Network [OSTI]

Modifications on the predictions about the matter power spectrum based on the hypothesis of a tiny contribution from a degenerate Fermi gas (DFG) test-fluid to some dominant cosmological scenario are investigated. Reporting about the systematic way of accounting for all the cosmological perturbations, through the Boltzmann equation we obtain the analytical results for density fluctuation, $\\delta$, and fluid velocity divergence, $\\theta$, of the DFG. Small contributions to the matter power spectrum are analytically obtained for the radiation-dominated background, through an ultra-relativistic approximation, and for the matter-dominated and $\\Lambda$-dominated eras, through a non-relativistic approximation. The results can be numerically reproduced and compared with those of considering non-relativistic and ultra-relativistic neutrinos into the computation of the matter power spectrum. Lessons concerning the formation of large scale structures of a DFG are depicted, and consequent deviations from standard $\\Lambda$CDM predictions for the matter power spectrum (with and without neutrinos) are quantified.

E. L. D. Perico; Alex E. Bernardini

2011-04-11T23:59:59.000Z

238

Controlled Population of Floquet-Bloch States via Coupling to Bose and Fermi Baths  

E-Print Network [OSTI]

External driving is emerging as a promising tool for exploring new phases in quantum systems. The intrinsically non-equilibrium states that result, however, are challenging to describe and control. We study the steady states of a periodically driven one-dimensional electronic system, including the effects of radiative recombination, electron-phonon interactions, and the coupling to an external fermionic reservoir. Using a kinetic equation for the populations of the Floquet eigenstates, we show that the steady-state distribution can be controlled using the momentum and energy relaxation pathways provided by the coupling to phonon and Fermi reservoirs. In order to utilize the latter, we propose to couple the system and reservoir via an energy filter which suppresses photon-assisted tunneling. Importantly, coupling to these reservoirs yields a steady state resembling a band insulator in the Floquet basis. The system exhibits incompressible behavior, while hosting a small density of excitations. We discuss transport signatures, and describe the regimes where insulating behavior is obtained. Our results give promise for realizing Floquet topological insulators.

Karthik I. Seetharam; Charles-Edouard Bardyn; Netanel H. Lindner; Mark S. Rudner; Gil Refael

2015-02-09T23:59:59.000Z

239

Braid group representations and cold Fermi gases in the fast pairing regime  

E-Print Network [OSTI]

It is widely recognized that the main difficulty in designing devices which could process information using quantum states is due to the decoherence of local excitations about a ground state. A solution to this problem was suggested in \\cite{Kitaev}, relying on (non-local) topological excitations, structurally protected against local noise. However, a practical implementation of this proposal using special Landau levels in fractional quantum Hall effect systems (FQHE) \\cite{QHE} has proven elusive, while accessible FQHE states are theoretically not optimal because their representations in the Hilbert space of states are not dense. We propose using a different physical system (cold Fermi atoms), whose semiclassical dynamics is described by a hyperelliptic function in the Sklyanin formalism. The homological structure of the complex curve corresponds to representations of the braid group, with the action of Hecke operators leading to singularities detectable in the semiclassical oscillations. We argue that, for a fixed genus of the hyperelliptic curve, the Richardson-Gaudin pairing Hamiltonian problem is the singular limit $m \\to \\infty$ of level-$k$ $\\widehat{sl}(2)$, with $k+2 = \\frac{4}{8m+1}\\to 0$, so that the level $k$ is admissible in the sense of Kac and Kazhdan \\cite{KK}, but the corresponding Hecke algebra is a $q-$deformation of the symmetric group with fixed $q = e^{i\\pi/4}$, as $m \\to \\infty$.

Bryce Hotalen; Razvan Teodorescu

2015-01-05T23:59:59.000Z

240

In-medium effects for nuclear matter in the Fermi energy domain  

E-Print Network [OSTI]

We study nuclear stopping in central collisions for heavy-ion induced reactions in the Fermi energy domain, between $15$ and $100$ A\\,\\textrm{MeV}. Using the large dataset of exclusive measurements provided by the $4\\pi$ array \\emph{INDRA}, we determine the relative degree of stopping as a function of system mass and bombarding energy. We show that the stopping can be directly related to the transport properties in the nuclear medium. By looking specifically at free nucleons (here protons), we present for the first time a comprehensive body of experimental results concerning the mean free path, the nucleon-nucleon cross-section and in-medium effects in nuclear matter. It is shown that the mean free path exhibits a maximum at $\\lambda_{NN}=9.5 \\pm 2$ \\textrm{fm}, around $E_{inc}=35-40$ A\\,\\textrm{MeV} incident energy and decreases toward an asymptotic value $\\lambda_{NN}= 4.5 \\pm 1$ \\textrm{fm} at $E_{inc} = 100$ A\\,\\textrm{MeV}. After accounting for Pauli blocking of elastic nucleon-nucleon collisions, it is ...

Lopez, O; Lehaut, G; Borderie, B; Rivet, M F; Bougault, R; Galichet, E; Guinet, D; Neindre, N Le; Marini, P; Napolitani, P; Pârlog, M; Rosato, E; Spadaccini, G; Vient, E; Vigilante, M

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

Ground-state and dynamical properties of two-dimensional dipolar Fermi liquids  

SciTech Connect (OSTI)

We study the ground-state properties of a two-dimensional spin-polarized fluid of dipolar fermions within the Euler–Lagrange Fermi-hypernetted-chain approximation. Our method is based on the solution of a scattering Schrödinger equation for the “pair amplitude” ?(g(r)), where g(r) is the pair distribution function. A key ingredient in our theory is the effective pair potential, which includes a bosonic term from Jastrow–Feenberg correlations and a fermionic contribution from kinetic energy and exchange, which is tailored to reproduce the Hartree–Fock limit at weak coupling. Very good agreement with recent results based on quantum Monte Carlo simulations is achieved over a wide range of coupling constants up to the liquid-to-crystal quantum phase transition. Using the fluctuation–dissipation theorem and a static approximation for the effective inter-particle interactions, we calculate the dynamical density–density response function, and furthermore demonstrate that an undamped zero-sound mode exists for any value of the interaction strength, down to infinitesimally weak couplings. -- Highlights: •We have studied the ground state properties of a strongly correlated two-dimensional fluid of dipolar fermions. •We have calculated the effective inter-particle interaction and the dynamical density–density response function. •We have shown that an undamped zero sound mode exists at any value of the interaction strength.

Abedinpour, Saeed H., E-mail: abedinpour@iasbs.ac.ir [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531 (Iran, Islamic Republic of); Asgari, Reza [School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531 (Iran, Islamic Republic of)] [School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531 (Iran, Islamic Republic of); Tanatar, B. [Department of Physics, Bilkent University, Bilkent, 06800 Ankara (Turkey)] [Department of Physics, Bilkent University, Bilkent, 06800 Ankara (Turkey); Polini, Marco [NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56126 Pisa (Italy)] [NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56126 Pisa (Italy)

2014-01-15T23:59:59.000Z

242

Isospin transport in 84Kr+112,124Sn reactions at Fermi energies  

E-Print Network [OSTI]

Isospin transport phenomena in dissipative heavy ion collisions have been investigated at Fermi energies with a beam of 84Kr at 35AMeV. A comparison of the /Z of light and medium products forward-emitted in the centre of mass frame when the beam impinges on a n-poor 112Sn and a n-rich 124Sn targets is presented. Data were collected by means of a three-layer telescope with very good performances in terms of mass identification (full isotopic resolution up to Z about 20 for ions punching through the first detector layer) built by the FAZIA Collaboration and located just beyond the grazing angle for both reactions. The /Z of the decay products emitted when the n-rich target is used is always higher than that associated to the n-poor one. Since the detector was able to measure only fragments coming from the QuasiProjectile decay and/or neck emission, the observed behaviour can be ascribed to the isospin diffusion, driven by the isospin gradient between QuasiProjectile and QuasiTarget. Moreover, for light fragments the /Z as a function of the lab velocity of the fragment increases when we move from the QuasiProjectile velocity to the centre of mass (neck zone). This effect can be interpreted as an evidence of isospin drift driven by the density gradient between the QuasiProjectile zone (at normal density) and the more diluted neck zone.

S. Piantelli; G. Casini; A. Olmi; S. Barlini; M. Bini; S. Carboni; P. R. Maurenzig; G. Pasquali; G. Poggi; A. A. Stefanini; R. Bougault; N. LeNeindre; O. Lopez; M. Parlog; E. Vient; E. Bonnet; A. Chbihi; J. D. Frankland; D. Gruyer; E. Rosato; G. Spadaccini; M. Vigilante; B. Borderie; M. F. Rivet; M. Bruno; L. Morelli; M. Cinausero; M. Degerlier; F. Gramegna; T. Marchi; R. Alba; C. Maiolino; D. Santonocito; T. Kozik; T. Twarog

2013-09-06T23:59:59.000Z

243

Measuring the bulk Lorentz factors of gamma-ray bursts with Fermi  

E-Print Network [OSTI]

Gamma-ray bursts (GRBs) are powered by ultra-relativistic jets. Usually a minimum value of the Lorentz factor of the relativistic bulk motion is obtained based on the argument that the observed high energy photons ($\\gg {\\rm MeV}$) can escape without suffering from absorption due to pair production. The exact value, rather than a lower limit, of the Lorentz factor can be obtained if the spectral cutoff due to such absorption is detected. With the good spectral coverage of the Large Area Telescope (LAT) on {\\em Fermi}, measurements of such cutoff become possible, and two cases (GRB 090926A and GRB 100724B) have been reported to have high-energy cutoffs or breaks. We systematically search for such high energy spectral cutoffs/breaks from LAT and GBM observations of the prompt emission of GRBs detected since August 2011. Seven more GRBs are found to have cutoff-like spectral feature at energies of $\\sim20-300$ MeV. Assuming that these cutoffs are caused by pair-production absorption within the source, the bulk L...

Tang, Qing-Wen; Wang, Xiang-Yu; Tam, Pak-Hin Thomas

2014-01-01T23:59:59.000Z

244

Pulsed Gamma-rays from PSR J2021+3651 with the Fermi Large Area Telescope  

E-Print Network [OSTI]

We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 +/- 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 +/- 0.004 +/- 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 +/- 3 +/- 11) x 10^{-8} /cm2/s. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE^{-\\Gamma} e^(-E/E_c) where the energy E is expressed in GeV. The photon index is \\Gamma = 1.5 +/- 0.1 +/- 0.1 and the exponential cut-off is E_c = 2.4 +/- 0.3 +/- 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is <10% o...

Abdo, A A

2009-01-01T23:59:59.000Z

245

Observations of Gamma-ray Bursts with ASTRO-H and Fermi  

E-Print Network [OSTI]

ASTRO-H, the sixth Japanese X-ray observatory, which is scheduled to be launched by the end of Japanese fiscal year 2015 has a capability to observe the prompt emission from Gamma-ray Bursts (GRBs) utilizing BGO active shields for the soft gamma-ray detector (SGD). The effective area of the SGD shield detectors is very large and its data acquisition system is optimized for short transients such as short GRBs. Thus, we expect to perform more detailed time-resolved spectral analysis with a combination of ASTRO-H and Fermi LAT/GBM to investigate the gamma-ray emission mechanism of short GRBs. In addition, the environment of the GRB progenitor should be a remarkable objective from the point of view of the chemical evolution of high-z universe. If we can maneuver the spacecraft to the GRBs, we can perform a high-resolution spectroscopy of the X-ray afterglow of GRBs utilizing the onboard micro calorimeter and X-ray CCD camera.

Ohno, M; Tashiro, M S; Ueno, H; Yonetoku, D; Sameshima, H; Takahashi, T; Seta, H; Mushotzky, R; Yamaoka, K

2015-01-01T23:59:59.000Z

246

Phase structure of mass- and spin-imbalanced unitary Fermi gases  

E-Print Network [OSTI]

We study the phase diagram of mass- and spin-imbalanced unitary Fermi gases, in search for the emergence of spatially inhomogeneous phases. To account for fluctuation effects beyond the mean-field approximation, we employ renormalization group techniques. We thus obtain estimates for critical values of the temperature, mass and spin imbalance, above which the system is in the normal phase. In the unpolarized, equal-mass limit, our result for the critical temperature is in accordance with state-of-the-art Monte Carlo calculations. In addition, we estimate the location of regions in the phase diagram where inhomogeneous phases are likely to exist. We show that an intriguing relation exists between the general structure of the many-body phase diagram and the binding energies of the underlying two-body bound-state problem, which further supports our findings. Our results suggest that inhomogeneous condensates form for mass ratios of the spin-down and spin-up fermions greater than three. The extent of the inhomoge...

Roscher, Dietrich; Drut, Joaquín E

2015-01-01T23:59:59.000Z

247

Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant  

SciTech Connect (OSTI)

We present an analysis of the gamma-ray measurements by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) Cygnus Loop (G74.0-8.5). We detect significant gamma-ray emission associated with the SNR in the energy band 0.2-100 GeV. The gamma-ray spectrum shows a break in the range 2-3 GeV. The gamma-ray luminosity is {approx} 1 x 10{sup 33} erg s{sup -1} between 1-100 GeV, much lower than those of other GeV-emitting SNRs. The morphology is best represented by a ring shape, with inner/outer radii 0{sup o}.7 {+-} 0{sup o}.1 and 1{sup o}.6 {+-} 0{sup o}.1. Given the association among X-ray rims, H{alpha} filaments and gamma-ray emission, we argue that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields adjacent to the shock regions. The decay of neutral pions produced in nucleon-nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray spectrum.

Katagiri, H.; /Ibaraki U., Mito; Tibaldo, L.; /INFN, Padua /Padua U. /Paris U., VI-VII; Ballet, J.; /Paris U., VI-VII; Giordano, F.; /Bari U. /Bari Polytechnic /INFN, Bari; Grenier, I.A.; /Paris U., VI-VII; Porter, T.A.; /Stanford U., HEPL /KIPAC, Menlo Park /SLAC; Roth, M.; /Washington U., Seattle; Tibolla, O.; /Wurzburg U.; Uchiyama, Y.; /Stanford U., HEPL /KIPAC, Menlo Park /SLAC; Yamazaki, R.; /Sagamihara, Aoyama Gakuin U.

2011-11-08T23:59:59.000Z

248

FERMI-LAT OBSERVATIONS AND A BROADBAND STUDY OF SUPERNOVA REMNANT CTB 109  

SciTech Connect (OSTI)

CTB 109 (G109.1-1.0) is a Galactic supernova remnant (SNR) with a hemispherical shell morphology in X-rays and in the radio band. In this work, we report the detection of {gamma}-ray emission coincident with CTB 109, using 37 months of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. We study the broadband characteristics of the remnant using a model that includes hydrodynamics, efficient cosmic-ray (CR) acceleration, nonthermal emission, and a self-consistent calculation of the X-ray thermal emission. We find that the observations can be successfully fit with two distinct parameter sets, one where the {gamma}-ray emission is produced primarily by leptons accelerated at the SNR forward shock and the other where {gamma}-rays produced by forward shock accelerated CR ions dominate the high-energy emission. Consideration of thermal X-ray emission introduces a novel element to the broadband fitting process, and while it does not rule out either the leptonic or the hadronic scenarios, it constrains the parameter sets required by the model to fit the observations. Moreover, the model that best fits the thermal and nonthermal emission observations is an intermediate case, where both radiation from accelerated electrons and hadrons contribute almost equally to the {gamma}-ray flux observed.

Castro, Daniel [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Slane, Patrick; Patnaude, Daniel J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ellison, Donald C. [Physics Department, North Carolina State University, Box 8202, Raleigh, NC 27695 (United States)

2012-09-01T23:59:59.000Z

249

FERMI-LAT AND WMAP OBSERVATIONS OF THE PUPPIS A SUPERNOVA REMNANT  

SciTech Connect (OSTI)

We report the detection of GeV {gamma}-ray emission from the supernova remnant (SNR) Puppis A with the Fermi Gamma-Ray Space Telescope. Puppis A is among the faintest SNRs yet detected at GeV energies, with a luminosity of only 2.7 Multiplication-Sign 10{sup 34} (D/2.2 kpc){sup 2} erg s{sup -1} between 1 and 100 GeV. The {gamma}-ray emission from the remnant is spatially extended, with a morphology matching that of the radio and X-ray emission, and is well described by a simple power law with an index of 2.1. We attempt to model the broadband spectral energy distribution (SED), from radio to {gamma}-rays, using standard nonthermal emission mechanisms. To constrain the relativistic electron population we use 7 years of Wilkinson Microwave Anisotropy Probe data to extend the radio spectrum up to 93 GHz. Both leptonic- and hadronic-dominated models can reproduce the nonthermal SED, requiring a total content of cosmic-ray electrons and protons accelerated in Puppis A of at least W {sub CR} Almost-Equal-To (1-5) Multiplication-Sign 10{sup 49} erg.

Hewitt, J. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grondin, M.-H. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Lemoine-Goumard, M.; Reposeur, T. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan, Universite Bordeaux 1, CNRS/IN2p3, F-33175 Gradignan (France); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Tanaka, T., E-mail: john.w.hewitt@nasa.gov, E-mail: marie-helene.grondin@mpi-hd.mpg.de, E-mail: lemoine@cenbg.in2p3.fr [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

2012-11-10T23:59:59.000Z

250

IDENTIFYING BREAKS AND CURVATURE IN THE FERMI SPECTRA OF BRIGHT FLAT SPECTRUM RADIO QUASARS  

SciTech Connect (OSTI)

Knowing the site of {gamma}-ray emission in active galactic nucleus jets will do much for our understanding of the physics of the source. In particular, if the emission region is close to the black hole then absorption of {gamma}-rays with photons from the broad-line region could become significant. Such absorption is predicted to produce two specific spectral breaks in the {gamma}-ray spectra of Flat Spectrum Radio Quasars (FSRQs). We test this hypothesis using three years of Fermi observations of nine bright FSRQs. A simple power-law fit to the spectrum of each source can be significantly improved by introducing a break, but the break energies are inconsistent with those predicted by the double-absorber model. In some cases the fit can be further improved by a log-parabola. In addition, by dividing the data from each source into two equal epochs we find that the best description of an object's spectrum often varies between a log-parabola and a broken power law.

Harris, J.; Daniel, M. K.; Chadwick, P. M., E-mail: j.d.harris@durham.ac.uk [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

2012-12-10T23:59:59.000Z

251

RADIO DETECTION OF THE FERMI-LAT BLIND SEARCH MILLISECOND PULSAR J1311-3430  

SciTech Connect (OSTI)

We report the detection of radio emission from PSR J1311-3430, the first millisecond pulsar (MSP) discovered in a blind search of Fermi Large Area Telescope (LAT) gamma-ray data. We detected radio pulsations at 2 GHz, visible for <10% of {approx}4.5 hr of observations using the Green Bank Telescope (GBT). Observations at 5 GHz with the GBT and at several lower frequencies with Parkes, Nancay, and the Giant Metrewave Radio Telescope resulted in non-detections. We also report the faint detection of a steep spectrum continuum radio source (0.1 mJy at 5 GHz) in interferometric imaging observations with the Jansky Very Large Array. These detections demonstrate that PSR J1311-3430 is not radio quiet and provide additional evidence that radio-quiet MSPs are rare. The radio dispersion measure of 37.8 pc cm{sup -3} provides a distance estimate of 1.4 kpc for the system, yielding a gamma-ray efficiency of 30%, typical of LAT-detected MSPs. We see apparent excess delay in the radio pulses as the pulsar appears from eclipse and we speculate on possible mechanisms for the non-detections of the pulse at other orbital phases and observing frequencies.

Ray, P. S.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Cheung, C. C. [National Academy of Sciences, Washington, DC 20001 (United States); Giroletti, M. [INAF Istituto di Radioastronomia, I-40129 Bologna (Italy); Cognard, I. [Laboratoire de Physique et Chimie de l'Environnement, LPCE UMR 6115 CNRS, F-45071 Orleans Cedex 02 (France); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bhattacharyya, B. [Inter-University Centre for Astronomy and Astrophysics, Pune 411 007 (India); Roy, J. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Romani, R. W.; Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ferrara, E. C. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Johnston, S.; Keith, M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping NSW 1710 (Australia); Pletsch, H. J. [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, D-30167 Hannover (Germany); Saz Parkinson, P. M., E-mail: Paul.Ray@nrl.navy.mil [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States)

2013-01-20T23:59:59.000Z

252

Fermi-LAT constraints on dark matter annihilation cross section from observations of the Fornax cluster  

SciTech Connect (OSTI)

We analyze 2.8-yr data of 1–100 GeV photons for clusters of galaxies, collected with the Large Area Telescope onboard the Fermi satellite. By analyzing 49 nearby massive clusters located at high Galactic latitudes, we find no excess gamma-ray emission towards directions of the galaxy clusters. Using flux upper limits, we show that the Fornax cluster provides the most stringent constraints on the dark matter annihilation cross section. Stacking a large sample of nearby clusters does not help improve the limit for most dark matter models. This suggests that a detailed modeling of the Fornax cluster is important for setting robust limits on the dark matter annihilation cross section based on clusters. We therefore perform the detailed mass modeling and predict the expected dark matter annihilation signals from the Fornax cluster, by taking into account effects of dark matter contraction and substructures. By modeling the mass distribution of baryons (stars and gas) around a central bright elliptical galaxy, NGC 1399, and using a modified contraction model motivated by numerical simulations, we show that the dark matter contraction boosts the annihilation signatures by a factor of 4. For dark matter masses around 10 GeV, the upper limit obtained on the annihilation cross section times relative velocity is (??)?<(2–3) × 10{sup ?25} cm{sup 3} s{sup ?1}, which is within a factor of 10 from the value required to explain the dark matter relic density. This effect is more robust than the annihilation boost due to substructure, and it is more important unless the mass of the smallest subhalos is much smaller than that of the Sun.

Ando, Shin'ichiro [Institute for Theoretical Physics, University of Amsterdam, 1090 GL Amsterdam (Netherlands); Nagai, Daisuke, E-mail: s.ando@uva.nl, E-mail: daisuke.nagai@yale.edu [Department of Physics, Yale University, New Haven, CT 06520 (United States)

2012-07-01T23:59:59.000Z

253

THE FERMI BUBBLES AS A SCALED-UP VERSION OF SUPERNOVA REMNANTS  

SciTech Connect (OSTI)

In this study, we treat Fermi bubbles as a scaled-up version of supernova remnants (SNRs). The bubbles are created through activities of the super-massive black hole (SMBH) or starbursts at the Galactic center (GC). Cosmic-rays (CRs) are accelerated at the forward shocks of the bubbles like SNRs, which means that we cannot decide whether the bubbles were created by the SMBH or starbursts from the radiation from the CRs. We follow the evolution of CR distribution by solving a diffusion-advection equation, considering the reduction of the diffusion coefficient by CR streaming. In this model, gamma rays are created through hadronic interaction between CR protons and the gas in the Galactic halo. In the GeV band, we can well reproduce the observed flat distribution of gamma-ray surface brightness because some amount of gas is left behind the shock. The edge of the bubbles is fairly sharp owing to the high gas density behind the shock and the reduction of the diffusion coefficient there. The latter also contributes the hard gamma-ray spectrum of the bubbles. We find that the CR acceleration at the shock began when the bubbles were small, and the time scale of the energy injection at the GC was much smaller than the age of the bubbles. We predict that if CRs are accelerated to the TeV regime, the apparent bubble size should be larger in the TeV band, which could be used to discriminate our hadronic model from other leptonic models. We also present neutrino fluxes.

Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)] [Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Ohira, Yutaka; Yamazaki, Ryo, E-mail: fujita@vega.ess.sci.osaka-u.ac.jp [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan)] [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan)

2013-09-20T23:59:59.000Z

254

THE INTERPLANETARY NETWORK SUPPLEMENT TO THE FERMI GBM CATALOG OF COSMIC GAMMA-RAY BURSTS  

SciTech Connect (OSTI)

We present Interplanetary Network (IPN) data for the gamma-ray bursts in the first Fermi Gamma-Ray Burst Monitor (GBM) catalog. Of the 491 bursts in that catalog, covering 2008 July 12 to 2010 July 11, 427 were observed by at least one other instrument in the nine-spacecraft IPN. Of the 427, the localizations of 149 could be improved by arrival time analysis (or {sup t}riangulation{sup )}. For any given burst observed by the GBM and one other distant spacecraft, triangulation gives an annulus of possible arrival directions whose half-width varies between about 0.'4 and 32 Degree-Sign , depending on the intensity, time history, and arrival direction of the burst, as well as the distance between the spacecraft. We find that the IPN localizations intersect the 1{sigma} GBM error circles in only 52% of the cases, if no systematic uncertainty is assumed for the latter. If a 6 Degree-Sign systematic uncertainty is assumed and added in quadrature, the two localization samples agree about 87% of the time, as would be expected. If we then multiply the resulting error radii by a factor of three, the two samples agree in slightly over 98% of the cases, providing a good estimate of the GBM 3{sigma} error radius. The IPN 3{sigma} error boxes have areas between about 1 arcmin{sup 2} and 110 deg{sup 2}, and are, on the average, a factor of 180 smaller than the corresponding GBM localizations. We identify two bursts in the IPN/GBM sample that did not appear in the GBM catalog. In one case, the GBM triggered on a terrestrial gamma flash, and in the other, its origin was given as ''uncertain''. We also discuss the sensitivity and calibration of the IPN.

Hurley, K. [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Pal'shin, V. D.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Mazets, E. P.; Svinkin, D. S. [Ioffe Physical Technical Institute, St. Petersburg 194021 (Russian Federation); Briggs, M. S.; Connaughton, V. [University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Meegan, C. [Universities Space Research Association, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Goldsten, J. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Boynton, W.; Fellows, C.; Harshman, K. [University of Arizona, Department of Planetary Sciences, Tucson, AZ 85721 (United States); Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Rau, A., E-mail: khurley@ssl.berkeley.edu [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Postfach 1312, D-85748 Garching (Germany); and others

2013-08-15T23:59:59.000Z

255

Bernard J. Baars How Brain Reveals Mind  

E-Print Network [OSTI]

Bernard J. Baars How Brain Reveals Mind Neural Studies Support the Fundamental Role of Conscious Experience Abstract: In the last decade, careful studies of the living brain have opened the way for human by seven cases: (1) the discovery of widespread brain activation during conscious perception; (2) high

Memphis, University of

256

Fish Population and Behavior Revealed by Instantaneous  

E-Print Network [OSTI]

Fish Population and Behavior Revealed by Instantaneous Continental Shelf­Scale Imaging Nicholas C-transect methods from slow-moving research vessels. These methods significantly undersample fish populations in time and space, leaving an incomplete and ambiguous record of abundance and behavior. We show that fish

257

Computer Simulations Reveal Multiple Functions for Aromatic  

E-Print Network [OSTI]

Computer Simulations Reveal Multiple Functions for Aromatic Residues in Cellulase Enzymes NREL researchers use high-performance computing to demonstrate fundamental roles of aromatic residues in cellulase enzyme tunnels. National Renewable Energy Laboratory (NREL) computer simulations of a key indus- trial

258

Fermi National Accelerator Laboratory / Kirk and Pine Street / P.O. Box 500 / Batavia, IL 60510 / 630.840.3000 / www.fnal.gov / fermilab@fnal.gov Managed by Fermi Research Alliance, LLC for the U.S. Department of Energy Office of Science  

E-Print Network [OSTI]

/ 630.840.3000 / www.fnal.gov / fermilab@fnal.gov Managed by Fermi Research Alliance, LLC for the U responsibility to notify Fermilab within 30 days if my dependent no longer meets the requirements as outlined

Quigg, Chris

259

The Search for High Energy Extended Emission by Fermi-LAT from Swift-Localized Gamma-Ray Bursts  

SciTech Connect (OSTI)

The brighter Fermi-LAT bursts have exhibited emission at energies >0.1 GeV that persists as late as {approx}2 ks after the prompt phase has nominally ended. This so-called 'extended emission' could arise from continued activity of the prompt burst mechanism or it could be the start of a high energy afterglow component. The high energy extended emission seen by the LAT has typically followed a t{sup -}{gamma} power-law temporal decay where {gamma} {approx} 1.2-1.7 and has shown no strong indication of spectral evolution. In contrast, the prompt burst emission generally displays strong spectral variability and more complex temporal changes in the LAT band. This differing behavior suggests that the extended emission likely corresponds to an early afterglow phase produced by an external shock. In this study, we look for evidence of high energy extended emission from 145 Swift-localized GRBs that have occurred since the launch of Fermi. A majority of these bursts were either outside of the LAT field-of-view or were otherwise not detected by the LAT during the prompt phase. However, because of the scanning operation of the Fermi satellite, the long-lived extended emission of these bursts may be detectable in the LAT data on the {approx}few ks time scale. We will look for emission from individual bursts and will perform a stacking analysis in order to set bounds on this emission for the sample as a whole. The detection of such emission would have implications for afterglow models and for the overall energy budget of GRBs.

Chiang, J.; /Stanford U., HEPL /SLAC; Racusin, J.L.; /NASA, Goddard

2012-05-01T23:59:59.000Z

260

FERMI/LAT OBSERVATIONS OF SWIFT/BAT SEYFERT GALAXIES: ON THE CONTRIBUTION OF RADIO-QUIET ACTIVE GALACTIC NUCLEI TO THE EXTRAGALACTIC {gamma}-RAY BACKGROUND  

SciTech Connect (OSTI)

We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R{sub X,BAT} where radio-loud objects have log R{sub X,BAT} > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be {approx}2 Multiplication-Sign 10{sup -11} photons cm{sup -2} s{sup -1}, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the {gamma}-ray (1-100 GeV) luminosity of {approx}< 3 Multiplication-Sign 10{sup 41} erg s{sup -1}. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

Teng, Stacy H.; Mushotzky, Richard F.; Reynolds, Christopher S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Sambruna, Rita M. [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030 (United States); Davis, David S., E-mail: stacyt@astro.umd.edu [CRESST and X-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)

2011-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" from the National Library of EnergyBeta (NLEBeta).
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261

Fermi-level shifts in graphene transistors with dual-cut channels scraped by atomic force microscope tips  

SciTech Connect (OSTI)

We investigate the electronic properties of p-type graphene transistors on silicon dioxide with dual-cut channels that were scraped using atomic force microscope tips. In these devices, the current is forced to squeeze into the path between the two cuts rather than flow directly through the graphene sheet. We observe that the gate voltages with minimum current shift toward zero bias as the sizes of the dual-cut regions increase. These phenomena suggest that the Fermi levels in the dual-cut regions are shifted toward the Dirac points after the mechanical scraping process.

Lin, Meng-Yu [Institute of Electronics, National Taiwan University, Taipei 10617, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan (China); Chen, Yen-Hao [Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Su, Chen-Fung [College of Photonics, National Chiao Tung University, Tainan 71150, Taiwan (China); Chang, Shu-Wei [Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan (China); Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Lee, Si-Chen [Institute of Electronics, National Taiwan University, Taipei 10617, Taiwan (China); Lin, Shih-Yen, E-mail: shihyen@gate.sinica.edu.tw [Institute of Electronics, National Taiwan University, Taipei 10617, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan (China); Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan (China)

2014-01-13T23:59:59.000Z

262

Exact solutions and stability of rotating dipolar Bose-Einstein condensates in the Thomas-Fermi limit  

E-Print Network [OSTI]

We present a theoretical analysis of dilute gas Bose-Einstein condensates with dipolar atomic interactions under rotation in elliptical traps. Working in the Thomas-Fermi limit, we employ the classical hydrodynamic equations to first derive the rotating condensate solutions and then consider their response to perturbations. We thereby map out the regimes of stability and instability for rotating dipolar Bose-Einstein condensates and in the latter case, discuss the possibility of vortex lattice formation. We employ our results to propose several novel routes to induce vortex lattice formation in a dipolar condensate.

R. M. W. van Bijnen; A. J. Dow; D. H. J. O'Dell; N. G. Parker; A. M. Martin

2009-05-10T23:59:59.000Z

263

Pulsed Gamma-Rays From PSR J2021 3651 with the Fermi Large Area Telescope  

SciTech Connect (OSTI)

We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 {+-} 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 {+-} 0.004 {+-} 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 {+-} 3 {+-} 11) x 10{sup -8} cm{sup -2} s{sup -1}. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE{sup -{Gamma}}e{sup (-E/E{sub c})} where the energy E is expressed in GeV. The photon index is {Gamma} = 1.5 {+-} 0.1 {+-} 0.1 and the exponential cut-off is E{sub c} = 2.4 {+-} 0.3 {+-} 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 {+-} 4 rad m{sup -2} but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, Marco; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, William B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, Milan; /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, Ronaldo; /INFN, Pisa; Berenji, Bijan; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bogaert, G.; /Ecole Polytechnique; Borgland, Anders W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /IASF, Milan /IASF, Milan /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Royal Inst. Tech., Stockholm /Stockholm U. /ASI, Rome /NRAO, Charlottesville /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Manchester U. /Montpellier U. /Bari U. /INFN, Bari; /more authors..

2011-11-30T23:59:59.000Z

264

MODELING THE NON-RECYCLED FERMI GAMMA-RAY PULSAR POPULATION  

SciTech Connect (OSTI)

We use Fermi Gamma-ray Space Telescope detections and upper limits on non-recycled pulsars obtained from the Large Area Telescope (LAT) to constrain how the gamma-ray luminosity L{sub ?} depends on the period P and the period derivative P-dot . We use a Bayesian analysis to calculate a best-fit luminosity law, or dependence of L{sub ?} on P and P-dot , including different methods for modeling the beaming factor. An outer gap (OG) magnetosphere geometry provides the best-fit model, which is L{sub ?}?P{sup -a} P-dot {sup b} where a = 1.36 ± 0.03 and b = 0.44 ± 0.02, similar to but not identical to the commonly assumed L{sub ?}??( E-dot )?P{sup -1.5} P-dot {sup 0.5}. Given upper limits on gamma-ray fluxes of currently known radio pulsars and using the OG model, we find that about 92% of the radio-detected pulsars have gamma-ray beams that intersect our line of sight. By modeling the misalignment of radio and gamma-ray beams of these pulsars, we find an average gamma-ray beaming solid angle of about 3.7? for the OG model, assuming a uniform beam. Using LAT-measured diffuse fluxes, we place a 2? upper limit on the average braking index and a 2? lower limit on the average surface magnetic field strength of the pulsar population of 3.8 and 3.2 × 10{sup 10} G, respectively. We then predict the number of non-recycled pulsars detectable by the LAT based on our population model. Using the 2 yr sensitivity, we find that the LAT is capable of detecting emission from about 380 non-recycled pulsars, including 150 currently identified radio pulsars. Using the expected 5 yr sensitivity, about 620 non-recycled pulsars are detectable, including about 220 currently identified radio pulsars. We note that these predictions significantly depend on our model assumptions.

Perera, B. B. P.; McLaughlin, M. A. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Cordes, J. M. [Astronomy Department and NAIC, Cornell University, Ithaca, NY 14853 (United States); Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Burnett, T. H. [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-10-10T23:59:59.000Z

265

Determination of the Fermi level position in dilute magnetic Ga{sub 1-x}Mn{sub x}N films  

SciTech Connect (OSTI)

We report on a combined theoretical and experimental determination of the Fermi level position in wurtzite Ga{sub 1?x}Mn{sub x}N films with x=4% and x=10% as grown by molecular beam epitaxy. By means of ellipsometric measurements, the real part of the frequency-dependent conductivity is determined. An electronic model in the framework of the effective bond-orbital model is parameterized in order to theoretically reproduce the measured transport properties. Predictions for the long-wavelength behaviour as a function of the Fermi level are made. The corresponding density of states obtained in this model is in qualitative agreement with first-principle calculations. The absence of a significant experimental peak in the AC conductivity for small frequencies indicates that the Fermi level lies in a gap between two Mn-related impurity bands in the host band gap.

Barthel, S., E-mail: sbarthel@itp.uni-bremen.de; Mourad, D.; Czycholl, G. [Institute for Theoretical Physics, University of Bremen, D-28359 Bremen (Germany); Kunert, G.; Figge, S.; Hommel, D. [Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany); Gartner, M.; Stoica, M. [Institute of Physical Chemistry “Ilie Murgulescu,” Romanian Academy, 060021 Bucharest (Romania); Kruse, C. [Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany); Department of Physics, University of Osnabrück, D-49076 Osnabrück (Germany)

2014-03-28T23:59:59.000Z

266

DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy...  

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

Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements March 16, 2010 - 4:28pm...

267

Research Led by Sandia Reveals Leading-Edge Erosion Significantly...  

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

Research Led by Sandia Reveals Leading-Edge Erosion Significantly Reduces Wind Turbine Performance Research Led by Sandia Reveals Leading-Edge Erosion Significantly Reduces Wind...

268

Computer modeling reveals how surprisingly potent hepatitis C...  

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

Hepatitis C computer modeling Computer modeling reveals how surprisingly potent hepatitis C drug works A study reveals how daclatasvir targets one of its proteins and causes the...

269

A Revealing Look Inside Passive and Active DPF Regeneration:...  

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

A Revealing Look Inside Passive and Active DPF Regeneration: In-Situ Optical Analysis of Ash Formation and Transport A Revealing Look Inside Passive and Active DPF Regeneration:...

270

Single-Molecule Dynamics Reveals Cooperative Binding-Folding...  

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

Molecule Dynamics Reveals Cooperative Binding-Folding in Protein Recognition . Single-Molecule Dynamics Reveals Cooperative Binding-Folding in Protein Recognition . Abstract: The...

271

Fermi LAT Observations of LS I +61 303: First Detection of an Orbital Modulation in GeV Gamma Rays  

SciTech Connect (OSTI)

This Letter presents the first results from the observations of LS I +61{sup o}303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 {+-} 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 {+-} 0.03(stat) {+-} 0.07(syst) 10{sup -6} ph cm{sup -2} s{sup -1}, with a cutoff at 6.3 {+-} 1.1(stat) {+-} 0.4(syst) GeV and photon index {Gamma} = 2.21 {+-} 0.04(stat) {+-} 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest that the link between HE and VHE gamma rays is nontrivial.

Abdo, A.A.; /Federal City Coll. /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, R.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /DAPNIA, Saclay /NASA, Goddard /CSST, Baltimore /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Grenoble, CEN; /more authors..

2012-04-02T23:59:59.000Z

272

Gamma-ray flaring activity from the gravitationally lensed blazar PKS 1830-211 observed by Fermi LAT  

E-Print Network [OSTI]

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the highly dust-absorbed, reddened, and MeV-peaked flat spectrum radio quasar PKS 1830-211 (z=2.507). Its apparent isotropic gamma-ray luminosity (E>100 MeV) averaged over $\\sim$ 3 years of observations and peaking on 2010 October 14/15 at 2.9 X 10^{50} erg s^{-1}, makes it among the brightest high-redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time delayed variability to follow about 25 days after a primary flare, with flux about a factor 1.5 less. Two large gamma-ray flares of PKS 1830-211 have been detected by the LAT in the considered period and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the gamma rays flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program ...

Abdo, A A; Ajello, M; Allafort, A; Amin, M A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bonamente, E; Borgland, A W; Bregeon, J; Brigida, M; Buehler, R; Bulmash, D; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cavazzuti, E; Cecchi, C; Charles, E; Cheung, C C; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Corbet, R H D; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Finke, J; Focke, W B; Fukazawa, Y; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Grenier, I A; Grove, J E; Guiriec, S; Hadasch, D; Hayashida, M; Hays, E; Hughes, R E; Inoue, Y; Jackson, M S; Jogler, T; Jňhannesson, G; Johnson, A S; Kamae, T; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Mazziotta, M N; Mehault, J; Michelson, P F; Mizuno, T; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohno, M; Ohsugi, T; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainň, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reyes, L C; Ritz, S; Romoli, C; Roth, M; Parkinson, P M Saz; Sgrň, C; Siskind, E J; Spandre, G; Spinelli, P; Takahashi, H; Takeuchi, Y; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Tronconi, V; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Werner, M; Winer, B L; Wood, K S

2014-01-01T23:59:59.000Z

273

Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background  

E-Print Network [OSTI]

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the n...

Ackermann, M; Albert, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Bloom, E D; Bonino, R; Bregeon, J; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caragiulo, M; Caraveo, P A; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cuoco, A; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giordano, F; Giroletti, M; Godfrey, G; Guiriec, S; Gustafsson, M; Hewitt, J W; Hou, X; Kamae, T; Kuss, M; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Malyshev, D; Massaro, F; Mayer, M; Mazziotta, M N; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Negro, M; Nemmen, R; Nuss, E; Ohsugi, T; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Raino, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Sanchez-Conde, M; Schulz, A; Sgro, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Troja, E; Uchiyama, Y; Vianello, G; Werner, M; Winer, B L; Wood, K S; Wood, M; Zaharijas, G

2015-01-01T23:59:59.000Z

274

{gamma}-RAY LUMINOSITY FUNCTION AND THE CONTRIBUTION TO EXTRAGALACTIC {gamma}-RAY BACKGROUND FOR FERMI-DETECTED BLAZARS  

SciTech Connect (OSTI)

We study {gamma}-ray luminosity functions (GLFs) and the contribution to the extragalactic diffuse {gamma}-rays for blazars. After using a clean blazar sample in which 485 blazars are observed at both the 8.4 GHz and {approx} GeV bands, we investigate the radio/{gamma}-ray luminosity correlation and find out that a strong correlation exists between the radio and {gamma}-ray luminosities using the partial correlation analysis method. Based on such a correlation, we obtain the GLF, while also considering the GLF based on studies of the X-ray luminosity function of active galactic nuclei and the GLF of the EGRET blazars. K-S tests indicate that these three kinds of GLFs are consistent with the observed data of our sample in a reasonable parameter range. Using these GLFs, we further investigate the blazar contribution to the extragalactic diffuse {gamma}-ray background (EGRB). Our results show that (1) the contribution of blazars are {approx}21.3% {+-} 2.7%, {approx}12.9% {+-} 1.7%, and {approx}37.9% {+-} 4.8% of unresolved Fermi EGRB flux for the three GLFs and (2) the contribution of flat-spectrum radio quasars are {approx}11.2% {+-} 1.6%, {approx}6.9% {+-} 1.0%, and {approx}9.0% {+-} 1.2% of unresolved Fermi EGRB flux for the three GLFs.

Zeng, H. D.; Yan, D. H.; Sun, Y. Q.; Zhang, L., E-mail: lizhang@ynu.edu.cn [Department of Physics, Yunnan University, Kunming (China)

2012-04-20T23:59:59.000Z

275

Fermi-LAT gamma-ray anisotropy and intensity explained by unresolved Radio-Loud Active Galactic Nuclei  

E-Print Network [OSTI]

Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic gamma-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the gamma-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations.

Mattia Di Mauro; Alessandro Cuoco; Fiorenza Donato; Jennifer M. Siegal-Gaskins

2014-07-11T23:59:59.000Z

276

REVISITING THE LONG/SOFT-SHORT/HARD CLASSIFICATION OF GAMMA-RAY BURSTS IN THE FERMI ERA  

SciTech Connect (OSTI)

We perform a statistical analysis of the temporal and spectral properties of the latest Fermi gamma-ray bursts (GRBs) to revisit the classification of GRBs. We find that the bimodalities of duration and the energy ratio (E{sub peak}/Fluence) and the anti-correlation between spectral hardness (hardness ratio (HR), peak energy, and spectral index) and duration (T{sub 90}) support the long/soft-short/hard classification scheme for Fermi GRBs. The HR-T{sub 90} anti-correlation strongly depends on the spectral shape of GRBs and energy bands, and the bursts with the curved spectra in the typical BATSE energy bands show a tighter anti-correlation than those with the power-law spectra in the typical BAT energy bands. This might explain why the HR-T{sub 90} correlation is not evident for those GRB samples detected by instruments like Swift with a narrower/softer energy bandpass. We also analyze the intrinsic energy correlation for the GRBs with measured redshifts and well-defined peak energies. The current sample suggests E{sub p,rest} = 2455 Multiplication-Sign (E{sub iso}/10{sup 52}){sup 0.59} for short GRBs, significantly different from that for long GRBs. However, both the long and short GRBs comply with the same E{sub p,rest}-L{sub iso} correlation.

Zhang Fuwen; Yan Jingzhi; Wei Daming [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Shao Lang, E-mail: fwzhang@pmo.ac.cn [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China)

2012-05-10T23:59:59.000Z

277

ALS Reveals New State of Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |November 2011Astudies smartHistory: The First 20ALS Reveals New

278

ALS Reveals New State of Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |November 2011Astudies smartHistory: The First 20ALS Reveals

279

ALS Reveals New State of Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations DuringALS DoctoralALS Reveals New State

280

ALS Reveals New State of Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations DuringALS DoctoralALS Reveals New

Note: This page contains sample records for the topic "fermi reveals entire" 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

ALS Reveals New State of Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations DuringALS DoctoralALS Reveals NewALS

282

Single-particle spectral density of the unitary Fermi gas: Novel approach based on the operator product expansion, sum rules and the maximum entropy method  

E-Print Network [OSTI]

Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

Gubler, Philipp; Hatsuda, Tetsuo; Nishida, Yusuke

2015-01-01T23:59:59.000Z

283

Single-particle spectral density of the unitary Fermi gas: Novel approach based on the operator product expansion, sum rules and the maximum entropy method  

E-Print Network [OSTI]

Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

Philipp Gubler; Naoki Yamamoto; Tetsuo Hatsuda; Yusuke Nishida

2015-01-24T23:59:59.000Z

284

"EntirelyBlackVerse from Him Would  

E-Print Network [OSTI]

AND HOWELLS 495 ington Cable, Henry James, Sarah Orne Jewett,Joel Chandler Harris, and MarkDunbar and His Song (New York:Dodd, Mead, and Co., 1947), p. 144. William Dean Howells ascended the professional

Goldberg, Bennett

285

The Arithmetic of Entire Functions under Composition  

E-Print Network [OSTI]

In this paper, we prove, among other things, that any family of noncons- ... at the Hong Kong University of Science and Technology, which is thanked for its ...

Eremenko, A., et al.

1996-12-26T23:59:59.000Z

286

Analysis reveals potential rangeland impacts if Williamson Act eliminated  

E-Print Network [OSTI]

Act, using a geospatial analysis and a mail question- naireelimination scenario. The geospatial analysis revealed that

Wetzel, William C; Lacher, Iara L; Swezey, Daniel s; Moffitt, Sarah E; Manning, Dale T

2012-01-01T23:59:59.000Z

287

Protein Vivisection Reveals Elusive Intermediates in Folding  

SciTech Connect (OSTI)

Although most folding intermediates escape detection, their characterization is crucial to the elucidation of folding mechanisms. Here, we outline a powerful strategy to populate partially unfolded intermediates: A buried aliphatic residue is substituted with a charged residue (e.g., Leu {yields} Glu{sup -}) to destabilize and unfold a specific region of the protein. We applied this strategy to ubiquitin, reversibly trapping a folding intermediate in which the {beta}5-strand is unfolded. The intermediate refolds to a native-like structure upon charge neutralization under mildly acidic conditions. Characterization of the trapped intermediate using NMR and hydrogen exchange methods identifies a second folding intermediate and reveals the order and free energies of the two major folding events on the native side of the rate-limiting step. This general strategy may be combined with other methods and have broad applications in the study of protein folding and other reactions that require trapping of high-energy states.

Zheng, Zhongzhou; Sosnick, Tobin R. (UC)

2010-05-25T23:59:59.000Z

288

FERMI-LAT OBSERVATIONS OF SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS: W41, MSH 17-39, AND G337.7-0.1  

E-Print Network [OSTI]

We report the detection of ?-ray emission coincident with three supernova remnants (SNRs) using data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. W41, G337.7-0.1, and MSH 17-39 are SNRs known ...

Castro, Daniel

289

Fermi Surface of SrFe2P2 Determined by the de Haasvan Alphen Effect J. G. Analytis,1,2  

E-Print Network [OSTI]

1 Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA 2 Geballe Laboratory for Advanced Materials 10 August 2009) We report measurements of the Fermi surface (FS) of the ternary iron-phosphide SrFe2P

Fisher, Ian

290

Fermi level de-pinning of aluminium contacts to n-type germanium using thin atomic layer deposited layers  

SciTech Connect (OSTI)

Fermi-level pinning of aluminium on n-type germanium (n-Ge) was reduced by insertion of a thin interfacial dielectric by atomic layer deposition. The barrier height for aluminium contacts on n-Ge was reduced from 0.7?eV to a value of 0.28?eV for a thin Al{sub 2}O{sub 3} interfacial layer (?2.8?nm). For diodes with an Al{sub 2}O{sub 3} interfacial layer, the contact resistance started to increase for layer thicknesses above 2.8?nm. For diodes with a HfO{sub 2} interfacial layer, the barrier height was also reduced but the contact resistance increased dramatically for layer thicknesses above 1.5?nm.

Gajula, D. R., E-mail: dgajula01@qub.ac.uk; Baine, P.; Armstrong, B. M.; McNeill, D. W. [School of Electronics, Electrical Engineering and Computer Science, Queen's University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH (United Kingdom)] [School of Electronics, Electrical Engineering and Computer Science, Queen's University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH (United Kingdom); Modreanu, M.; Hurley, P. K. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)] [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

2014-01-06T23:59:59.000Z

291

Exact solution for the degenerate ground-state manifold of a strongly interacting one-dimensional Bose-Fermi mixture  

SciTech Connect (OSTI)

We present the exact solution for the many-body wavefunction of a one-dimensional mixture of bosons and spin-polarized fermions with equal masses and infinitely strong repulsive interactions under external confinement. Such a model displays a large degeneracy of the ground state. Using a generalized Bose-Fermi mapping, we find the solution for the whole set of ground-state wave functions of the degenerate manifold and we characterize them according to group-symmetry considerations. We find that the density profile and the momentum distribution depends on the symmetry of the solution. By combining the wave functions of the degenerate manifold with suitable symmetry and guided by the strong-coupling form of the Bethe-Ansatz solution for the homogeneous system, we propose an analytic expression for the many-body wave function of the inhomogeneous system which well describes the ground state at finite, large, and equal interaction strengths, as validated by numerical simulations.

Fang, Bess [Department of Physics, Block S12, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Vignolo, Patrizia; Gattobigio, Mario [Universite de Nice-Sophia Antipolis, Institut Non Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Miniatura, Christian [Department of Physics, Block S12, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Universite de Nice-Sophia Antipolis, Institut Non Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Minguzzi, Anna [Universite Grenoble 1, CNRS, LPMMC, UMR5493, Maison des Magisteres, F-38042 Grenoble (France)

2011-08-15T23:59:59.000Z

292

Efficient integration of the variational equations of multi-dimensional Hamiltonian systems: Application to the Fermi-Pasta-Ulam lattice  

E-Print Network [OSTI]

We study the problem of efficient integration of variational equations in multi-dimensional Hamiltonian systems. For this purpose, we consider a Runge-Kutta-type integrator, a Taylor series expansion method and the so-called `Tangent Map' (TM) technique based on symplectic integration schemes, and apply them to the Fermi-Pasta-Ulam $\\beta$ (FPU-$\\beta$) lattice of $N$ nonlinearly coupled oscillators, with $N$ ranging from 4 to 20. The fast and accurate reproduction of well-known behaviors of the Generalized Alignment Index (GALI) chaos detection technique is used as an indicator for the efficiency of the tested integration schemes. Implementing the TM technique--which shows the best performance among the tested algorithms--and exploiting the advantages of the GALI method, we successfully trace the location of low-dimensional tori.

Enrico Gerlach; Siegfried Eggl; Charalampos Skokos

2011-04-15T23:59:59.000Z

293

Schottky barrier height reduction for holes by Fermi level depinning using metal/nickel oxide/silicon contacts  

SciTech Connect (OSTI)

We report the experimental demonstration of Fermi level depinning using nickel oxide (NiO) as the insulator material in metal-insulator-semiconductor (M-I-S) contacts. Using this contact, we show less than 0.1?eV barrier height for holes in platinum/NiO/silicon (Pt/NiO/p-Si) contact. Overall, the pinning factor was improved from 0.08 (metal/Si) to 0.26 (metal/NiO/Si). The experimental results show good agreement with that obtained from theoretical calculation. NiO offers high conduction band offset and low valence band offset with Si. By reducing Schottky barrier height, this contact can be used as a carrier selective contact allowing hole transport but blocking electron transport, which is important for high efficiency in photonic applications such as photovoltaics and optical detectors.

Islam, Raisul, E-mail: raisul@stanford.edu; Shine, Gautam; Saraswat, Krishna C. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

2014-11-03T23:59:59.000Z

294

Fitting the Fermi-LAT GeV excess: on the importance of the propagation of electrons from dark matter  

E-Print Network [OSTI]

An excess of gamma rays at GeV energies has been detected in the Fermi-LAT data. This signal comes from a narrow region around the Galactic Center and has been interpreted as possible evidence for light (30 GeV) dark matter particles. Focussing on the prompt gamma-ray emission, previous works found that the best fit to the data corresponds to annihilations proceeding into b quarks, with a dark matter profile going as r^{-1.2}. We show that this is not the only possible annihilation set-up. More specifically, we show how including the contributions to the gamma-ray spectrum from inverse Compton scattering and bremsstrahlung from electrons produced in dark matter annihilations, and undergoing diffusion through the Galactic magnetic field, significantly affects the spectrum for leptonic final states. This drastically changes the interpretation of the excess in terms of dark matter.

Lacroix, Thomas

2015-01-01T23:59:59.000Z

295

A one-dimensional Fermi accelerator model with moving wall described by a nonlinear van der Pol oscillator  

E-Print Network [OSTI]

A modification of the one-dimensional Fermi accelerator model is considered in this work. The dynamics of a classical particle of mass $m$, confined to bounce elastically between two rigid walls where one is described by a non-linear van der Pol type oscillator while the other one is fixed, working as a re-injection mechanism of the particle for a next collision, is carefully made by the use of a two-dimensional non-linear mapping. Two cases are considered: (i) the situation where the particle has mass negligible as compared to the mass of the moving wall and does not affect the motion of it; (ii) the case where collisions of the particle does affect the movement of the moving wall. For case (i) the phase space is of mixed type leading us to observe a scaling of the average velocity as a function of the parameter ($\\c{hi}$) controlling the non-linearity of the moving wall. For large $\\c{hi}$, a diffusion on the velocity is observed leading us to conclude that Fermi acceleration is taking place. On the other hand for case (ii), the motion of the moving wall is affected by collisions with the particle. However due to the properties of the van der Pol oscillation, the moving wall relaxes again to a limit cycle. Such kind of motion absorbs part of the energy of the particle leading to a suppression of the unlimited energy gain as observed in case (i). The phase space shows a set of attractors of different periods whose basin of attraction has a complicate organization.

Tiago Botari; Edson Denis Leonel

2012-06-18T23:59:59.000Z

296

Fermi-LAT Discovery of Extended Gamma-Ray Emission in the Direction of Supernova Remnant W51C  

SciTech Connect (OSTI)

The discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. W51C is a middle-aged remnant ({approx}10{sup 4} yr) with intense radio synchrotron emission in its shell and known to be interacting with a molecular cloud. The gamma-ray emission is spatially extended, broadly consistent with the radio and X-ray extent of SNR W51C. The energy spectrum in the 0.2-50 GeV band exhibits steepening toward high energies. The luminosity is greater than 1 x 10{sup 36} erg s{sup -1} given the distance constraint of D > 5.5 kpc, which makes this object one of the most luminous gamma-ray sources in our Galaxy. The observed gamma-rays can be explained reasonably by a combination of efficient acceleration of nuclear cosmic rays at supernova shocks and shock-cloud interactions. The decay of neutral p mesons produced in hadronic collisions provides a plausible explanation for the gamma-ray emission. The product of the average gas density and the total energy content of the accelerated protons amounts to {bar n}{sub H} W{sub p} {approx_equal} 5 x 10{sup 51} (D/6 kpc){sup 2} erg cm{sup -3}. Electron density constraints from the radio and X-ray bands render it difficult to explain the LAT signal as due to inverse Compton scattering. The Fermi LAT source coincident with SNR W51C sheds new light on the origin of Galactic cosmic rays.

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Baring, M.G.; /Rice U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bouvier, A.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Washington U., Seattle /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U. /Stockholm U., OKC /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique; /more authors..

2012-03-30T23:59:59.000Z

297

Two Studies Reveal Details of Lithium-Battery Function  

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

Two Studies Reveal Details of Lithium-Battery Function Two Studies Reveal Details of Lithium-Battery Function Print Wednesday, 27 February 2013 00:00 Our way of life is deeply...

298

Unusual light in dark space revealed by Los Alamos, NASA  

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

Unusual light in dark space revealed by Los Alamos, NASA Unusual light in dark space revealed by Los Alamos, NASA By looking at the dark spaces between visible galaxies and stars...

299

Study Reveals Challenges and Opportunities Related to Vessels...  

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

Study Reveals Challenges and Opportunities Related to Vessels for U.S. Offshore Wind Study Reveals Challenges and Opportunities Related to Vessels for U.S. Offshore Wind October 1,...

300

Secrets of the Motor That Drives Archaea Revealed  

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

Secrets of the Motor That Drives Archaea Revealed Secrets of the Motor That Drives Archaea Revealed Print Thursday, 14 February 2013 00:00 An international team led by John Tainer...

Note: This page contains sample records for the topic "fermi reveals entire" 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.


301

Observation of an electron band above the Fermi level in FeTe{sub 0.55}Se{sub 0.45} from in-situ surface doping  

SciTech Connect (OSTI)

We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe{sub 0.55}Se{sub 0.45}. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily electron-doped KFe{sub 2?x}Se{sub 2} compound.

Zhang, P.; Ma, J.; Qian, T. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Richard, P., E-mail: p.richard@iphy.ac.cn; Ding, H., E-mail: dingh@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Xu, N. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Paul Scherrer Institut, Swiss Light Source, CH-5232 Villigen PSI (Switzerland); Xu, Y.-M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fedorov, A. V.; Denlinger, J. D. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Gu, G. D. [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2014-10-27T23:59:59.000Z

302

FINAL–REPORT NO. 2: INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE ENRICO FERMI ATOMIC POWER PLANT, UNIT 1, NEWPORT, MICHIGAN (DOCKET NO. 50 16; RFTA 10-004)  

SciTech Connect (OSTI)

The Enrico Fermi Atomic Power Plant, Unit 1 (Fermi 1) was a fast breeder reactor design that was cooled by sodium and operated at essentially atmospheric pressure. On May 10, 1963, the Atomic Energy Commission (AEC) granted an operating license, DPR-9, to the Power Reactor Development Company (PRDC), a consortium specifically formed to own and operate a nuclear reactor at the Fermi 1 site. The reactor was designed for a maximum capability of 430 megawatts (MW); however, the maximum reactor power with the first core loading (Core A) was 200 MW. The primary system was filled with sodium in December 1960 and criticality was achieved in August 1963.

Erika Bailey

2011-07-07T23:59:59.000Z

303

HST SPECTRAL MAPPING OF L/T TRANSITION BROWN DWARFS REVEALS CLOUD THICKNESS VARIATIONS  

SciTech Connect (OSTI)

Most directly imaged giant exoplanets are fainter than brown dwarfs with similar spectra. To explain their relative underluminosity, unusually cloudy atmospheres have been proposed. However, with multiple parameters varying between any two objects, it remained difficult to observationally test this idea. We present a new method, sensitive time-resolved Hubble Space Telescope near-infrared spectroscopy, to study two rotating L/T transition brown dwarfs (2M2139 and SIMP0136). The observations provide spatially and spectrally resolved mapping of the cloud decks of the brown dwarfs. The data allow the study of cloud structure variations while other parameters are unchanged. We find that both brown dwarfs display variations of identical nature: J- and H-band brightness variations with minimal color and spectral changes. Our light curve models show that even the simplest surface brightness distributions require at least three elliptical spots. We show that for each source the spectral changes can be reproduced with a linear combination of only two different spectra, i.e., the entire surface is covered by two distinct types of regions. Modeling the color changes and spectral variations together reveal patchy cloud covers consisting of a spatially heterogeneous mix of low-brightness, low-temperature thick clouds and brighter, thin, and warm clouds. We show that the same thick cloud patches seen in our varying brown dwarf targets, if extended to the entire photosphere, predict near-infrared colors/magnitudes matching the range occupied by the directly imaged exoplanets that are cooler and less luminous than brown dwarfs with similar spectral types. This supports the models in which thick clouds are responsible for the near-infrared properties of these ''underluminous'' exoplanets.

Apai, Daniel [Department of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Radigan, Jacqueline; Jayawardhana, Ray [Department of Astronomy, University of Toronto, 50 St. George Street, Toronto M5S 3H4 (Canada); Buenzli, Esther [Department of Astronomy and Steward Observatory, 933 N. Cherry Avenue, University of Arizona, Tucson, AZ 85721 (United States); Burrows, Adam [Department of Astrophysical Sciences, 105 Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Reid, Iain Neill, E-mail: apai@as.arizona.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21212 (United States)

2013-05-10T23:59:59.000Z

304

Isospin-breaking corrections to superallowed Fermi beta-decay in isospin- and angular-momentum-projected nuclear Density Functional Theory  

E-Print Network [OSTI]

Background: The superallowed beta-decay rates provide stringent constraints on physics beyond the Standard Model of particle physics. To extract crucial information about the electroweak force, small isospin-breaking corrections to the Fermi matrix element of superallowed transitions must be applied. Purpose: We perform systematic calculations of isospin-breaking corrections to superallowed beta-decays and estimate theoretical uncertainties related to the basis truncation, time-odd polarization effects related to the intrinsic symmetry of the underlying Slater determinants, and to the functional parametrization. Methods: We use the self-consistent isospin- and angular-momentum-projected nuclear density functional theory employing two density functionals derived from the density independent Skyrme interaction. Pairing correlations are ignored. Our framework can simultaneously describe various effects that impact matrix elements of the Fermi decay: symmetry breaking, configuration mixing, and long-range Coulomb polarization. Results: The isospin-breaking corrections to the I=0+,T=1 --> I=0+,T=1 pure Fermi transitions are computed for nuclei from A=10 to A=98 and, for the first time, to the Fermi branch of the I,T=1/2 --> I,T=1/2 transitions in mirror nuclei from A=11 to A=49. We carefully analyze various model assumptions impacting theoretical uncertainties of our calculations and provide theoretical error bars on our predictions. Conclusions: The overall agreement with empirical isospin-breaking corrections is very satisfactory. Using computed isospin-breaking corrections we show that the unitarity of the CKM matrix is satisfied with a precision better than 0.1%.

W. Satula; J. Dobaczewski; W. Nazarewicz; T. R. Werner

2012-10-25T23:59:59.000Z

305

Thomas-Fermi for Al+ Following the discusions on the positive ions in the lecture notes, we need to find c'(0) so that  

E-Print Network [OSTI]

Thomas-Fermi for Al+ Following the discusions on the positive ions in the lecture notes, we need to find c'(0) so that x0 c' Hx0 L = -HZ - NLĂŞ Z = -1 ĂŞ13 for Al+ . After some trial-and-error, I find c' H.7649 Now make sure x0 c' Hx0 L = -1 ĂŞ13, AlTF.nb 1 #12;In[4]:= Z x c'@xD ĂŞ. chisol ĂŞ. 8x Ă? x0

Murayama, Hitoshi

306

Hall, Seebeck, and Nernst Coefficients of Underdoped HgBa2CuO4+?: Fermi-Surface Reconstruction in an Archetypal Cuprate Superconductor  

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

Charge-density-wave order has been observed in cuprate superconductors whose crystal structure breaks the square symmetry of the CuO2 planes, such as orthorhombic YBa2Cu3Oy (YBCO), but not so far in cuprates that preserve that symmetry, such as tetragonal HgBa2CuO4+? (Hg1201). We have measured the Hall (RH), Seebeck (S), and Nernst (?) coefficients of underdoped Hg1201 in magnetic fields large enough to suppress superconductivity. The high-field RH(T) and S(T) are found to drop with decreasing temperature and become negative, as also observed in YBCO at comparable doping. In YBCO, the negative RH and S are signatures of a small electron pocket caused by Fermi-surface reconstruction, attributed to charge-density-wave modulations observed in the same range of doping and temperature. We deduce that a similar Fermi-surface reconstruction takes place in Hg1201, evidence that density-wave order exists in this material. A striking similarity is also found in the normal-state Nernst coefficient ?(T), further supporting this interpretation. Given the model nature of Hg1201, Fermi-surface reconstruction appears to be common to all hole-doped cuprates, suggesting that density-wave order is a fundamental property of these materials.

Doiron-Leyraud, Nicolas; Lepault, S.; Cyr-Choiničre, O.; Vignolle, B.; Grissonnanche, G.; Laliberté, F.; Chang, J.; Bariši?, N.; Chan, M. K.; Ji, L.; Zhao, X.; Li, Y.; Greven, M.; Proust, C.; Taillefer, Louis

2013-06-01T23:59:59.000Z

307

A fermi liquid electric structure and the nature of the carriers in high-T/sub c/ cuprates: A photoemission study  

SciTech Connect (OSTI)

We have performed angle-integrated and angle-resolved photoemission measurements at 20 K on well-characterized single crystals of high-T/sub c/ cuprates (both 1:2:3-type and 2:2:1:2-type) cleaved in situ, and find a relatively large, resolution limited Fermi edge which shows large amplitude variations with photon energy, indicative of band structure final state effects. The lineshapes of the spectra of the 1:2:3 materials as a function of photon energy are well reproduced by band structure predictions, indicating a correct mix of 2p and 3d orbitals on the calculations, while the energy positions of the peaks agree with calculated bands only to within /approx/0.5 eV. This may yet prove to reflect the effects of Coulomb correlation. We nevertheless conclude that a Fermi liquid approach to conductivity is appropriate. Angle-resolved data, while still incomplete, suggest agreement with the Fermi surface predicted by the LDA calculations. A BCS-like energy gap is observed in the 2:2:1:2 materials, whose magnitude is twice the weak coupling BCS value (i.e., 2/Delta/ = 7 KT/sub c/). 49 refs., 11 figs.

Arko, A.J.; List, R.S.; Bartlett, R.J.; Cheong, S.W.; Fisk, Z.; Thompson, J.D.; Olson, C.G.; Yang, A.B.; Liu, R.; Gu, C.; Veal, B.W.; Liu, J.Z.; Paulikas, A.P.; Vandervoort, K.; Claus, H.; Campuzano, J.C.; Schirber, J.E.; Shinn, N.D.

1989-01-01T23:59:59.000Z

308

Improved limits on sterile neutrino dark matter from full-sky observations by the Fermi-GBM  

E-Print Network [OSTI]

For the first time, we use the Gamma-ray Burst Monitor (GBM) on-board the Fermi satellite to search for sterile neutrino decay lines in the energy range 10-25 keV corresponding to sterile neutrino mass range 20-50 keV. This energy range has been out of reach of traditional X-ray satellites such as Chandra, Suzaku, XMM-Newton, and gamma-ray satellites such as INTEGRAL. Furthermore, the extremely wide field of view of the GBM opens a large fraction of the Milky Way dark matter halo to be probed. We start with 1601 days worth of GBM data, implement stringent data cuts, and perform two simple line search analyses on the reduced data: in the first, the line flux is limited without background modeling, and in the second, the background is modeled as a power-law. We find no significant excess lines in both our searches. We set new limits on sterile neutrino mixing angles, improving on previous limits by approximately an order of magnitude. Better understanding of detector and astrophysical backgrounds, as well as de...

Horiuchi, Shunsaku; Gaskins, Jennifer M; Smith, Miles; Preece, Robert

2015-01-01T23:59:59.000Z

309

PSR J2021+4026 IN THE GAMMA CYGNI REGION: THE FIRST VARIABLE ?-RAY PULSAR SEEN BY THE Fermi LAT  

SciTech Connect (OSTI)

Long-term monitoring of PSR J2021+4026 in the heart of the Cygnus region with the Fermi Large Area Telescope unveiled a sudden decrease in flux above 100 MeV over a timescale shorter than a week. The 'jump' was near MJD 55850 (2011 October 16), with the flux decreasing from (8.33 ± 0.08) × 10{sup –10} erg cm{sup –2} s{sup –1} to (6.86 ± 0.13) × 10{sup –10} erg cm{sup –2} s{sup –1}. Simultaneously, the frequency spindown rate increased from (7.8 ± 0.1) × 10{sup –13} Hz s{sup –1} to (8.1 ± 0.1) × 10{sup –13} Hz s{sup –1}. Significant (>5?) changes in the pulse profile and marginal (<3?) changes in the emission spectrum occurred at the same time. There is also evidence for a small, steady flux increase over the 3 yr preceding MJD 55850. This is the first observation at ?-ray energies of mode changes and intermittent behavior, observed at radio wavelengths for other pulsars. We argue that the change in pulsed ?-ray emission is due to a change in emission beaming and we speculate that it is precipitated by a shift in the magnetic field structure, leading to a change of either effective magnetic inclination or effective current.

Allafort, A.; Bottacini, E.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)] [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Universitŕ di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy)] [Universitŕ di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Ballet, J.; Chaves, R.C.G. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France)] [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P. O. Box 1892, Houston, TX 77251 (United States)] [Rice University, Department of Physics and Astronomy, MS-108, P. O. Box 1892, Houston, TX 77251 (United States); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France)] [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany)] [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Caliandro, G. A. [Institut de Cičncies de l'Espai (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain)] [Institut de Cičncies de l'Espai (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain); Caraveo, P. A. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy)] [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); Chekhtman, A., E-mail: ltibaldo@slac.stanford.edu, E-mail: massimiliano.razzano@pi.infn.it [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030, resident at Naval Research Laboratory, Washington, DC 20375 (United States); and others

2013-11-01T23:59:59.000Z

310

Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope  

SciTech Connect (OSTI)

Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.

Ackermann, M.; Ajello, M.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Albert, A.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Atwood, W.B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Bechtol, K.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari Polytechnic /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Buehler, R.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Burnett, T.H.; /Washington U., Seattle; Buson, S.; /INFN, Padua /Padua U. /ICE, Bellaterra /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /INFN, Rome /Rome U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Artep Inc. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /ASDC, Frascati /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /ASDC, Frascati /ASDC, Frascati /Udine U. /INFN, Trieste /Bari Polytechnic /INFN, Bari /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /NASA, Goddard /Hiroshima U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Bari Polytechnic /INFN, Bari /INFN, Bari /ASDC, Frascati /NASA, Goddard /INFN, Perugia /Perugia U. /Bari Polytechnic /INFN, Bari /Bologna Observ. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /DAPNIA, Saclay /Alabama U., Huntsville; /more authors..

2012-09-14T23:59:59.000Z

311

Neutral current quasielastic (anti)neutrino scattering beyond the Fermi gas model at MiniBooNE and BNL kinematics  

E-Print Network [OSTI]

Neutral current quasielastic (anti)neutrino scattering cross sections on a $^{12}$C target are analyzed using a realistic spectral function $S(p,E)$ that gives a scaling function in accordance with the ($e,e'$) scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals (NOs) from the Jastrow correlation method and has a realistic energy dependence. The standard value of the axial mass $M_A= 1.032$ GeV is used in all calculations. The role of the final-state interaction (FSI) on the spectral and scaling functions, as well as on the cross sections is accounted for. A comparison of the calculations with the empirical data of the MiniBooNE and BNL experiments is performed. Our results are analyzed in comparison with those when NN correlations are not included, and also with results from other theoretical approaches, such as the relativistic Fermi gas (RFG), the relativistic mean field (RMF), the relativistic Green's function (RGF), as well as with the SuperScaling Approach (SuSA) based on the analysis of quasielastic electron scattering.

M. V. Ivanov; A. N. Antonov; M. B. Barbaro; C. Giusti; A. Meucci; J. A. Caballero; R. Gonzalez-Jimenez; E. Moya de Guerra; J. M. Udias

2015-03-14T23:59:59.000Z

312

Interaction energy and itinerant ferromagnetism in a strongly interacting Fermi gas in the absence of molecule formation  

E-Print Network [OSTI]

We investigate the interaction energy and the possibility of itinerant ferromagnetism in a strongly interacting Fermi gas at zero temperature in the absence of molecule formation. The interaction energy is obtained by summing the perturbative contributions of Galitskii-Feynman type to all orders in the gas parameter. It can be expressed by a simple phase space integral of an in-medium scattering phase shift. In both three and two dimensions (3D and 2D), the interaction energy shows a maximum before reaching the resonance from the Bose-Einstein condensate side, which provides a possible explanation of the experimental measurements of the interaction energy. This phenomenon can be theoretically explained by the qualitative change of the nature of the binary interaction in the medium. The appearance of an energy maximum has significant effects on the itinerant ferromagnetism. In 3D, the ferromagnetic transition is reentrant and itinerant ferromagnetism exists in a narrow window around the energy maximum. In 2D, the present theoretical approach suggests that itinerant ferromagnetism does not exist, which reflects the fact that the energy maximum becomes much lower than the energy of the fully polarized state.

Lianyi He

2014-11-26T23:59:59.000Z

313

The radio/gamma-ray connection in Active Galactic Nuclei in the era of the Fermi Large Area Telescope  

E-Print Network [OSTI]

We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the Active Galactic Nuclei (AGN) detected by Fermi during its first year of operation, with the largest datasets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the VLA and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate-data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the cm radio and the broad band (E>100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability <1e-7 for the correlation appearing by chance. Using the...

Ackermann, M; Allafort, A; Angelakis, E; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Cannon, A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C C; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cutini, S; de Palma, F; Dermer, C D; Silva, E do Couto e; Drell, P S; Dubois, R; Dumora, D; Escande, L; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fuhrmann, L; Fukazawa, Y; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grandi, P; Grenier, I A; Guiriec, S; Hadasch, D; Hayashida, M; Hays, E; Healey, S E; J, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Kn, J; Kuss, M; Lande, J; Lee, S -H; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Makeev, A; Max-Moerbeck, W; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Nishino, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Pavlidou, V; Pelassa, V; Pepe, M; Pesce-Rollins, M; Pierbattista, M; Piron, F; Porter, T A; Rain, S; Razzano, M; Readhead, A; Reimer, A; Reimer, O; Richards, J L; Romani, R W; Sadrozinski, H F -W; Scargle, J D; Sgr, C; Siskind, E J; Smith, P D; Spandre, G; Spinelli, P; Strickman, M S; Suson, D J; Takahashi, H; Tanaka, T; Taylor, G B; Thayer, J G; Thayer, J B; Thompson, D J; Torres, D F; Tosti, G; Tramacere, A; Troja, E; Vandenbroucke, J; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yang, Z; Ziegler, M

2011-01-01T23:59:59.000Z

314

Synchrotron Cooling in Energetic Gamma-Ray Bursts Observed by the Fermi Gamma-Ray Burst Monitor  

E-Print Network [OSTI]

We study the time-resolved spectra of eight GRBs observed by Fermi GBM in its first five years of mission, with 1 keV - 1 MeV fluence $f>1.0\\times10^{-4}$ erg cm$^{-2}$ and signal-to-noise level $\\text{S/N}\\geq10.0$ above 900 keV. We aim to constrain in detail the spectral properties of GRB prompt emission on a time-resolved basis and to discuss the theoretical implications of the fitting results in the context of various prompt emission models. We perform time-resolved spectral analysis using a variable temporal binning technique according to optimal S/N criteria, resulting in a total of 299 time-resolved spectra. We fit the Band function to all spectra and obtain the distributions for the low-energy power-law index $\\alpha$, the high-energy power-law index $\\beta$, the peak energy in the observed $\

Yu, Hoi-Fung; van Eerten, Hendrik; Burgess, J Michael; Bhat, P Narayana; Briggs, Michael S; Connaughton, Valerie; Diehl, Roland; Goldstein, Adam; Gruber, David; Jenke, Peter A; von Kienlin, Andreas; Kouveliotou, Chryssa; Paciesas, William S; Pelassa, Veronique; Preece, Robert D; Roberts, Oliver J; Zhang, Bin-Bin

2014-01-01T23:59:59.000Z

315

Search for Gamma-Ray Emission from DES Dwarf Spheroidal Galaxy Candidates with Fermi-LAT Data  

E-Print Network [OSTI]

Due to their proximity, high dark matter content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection of dark matter. Recently, eight new dSph candidates were discovered using the first year of data from the Dark Energy Survey (DES). We searched for gamma-ray emission coincident with the positions of these new objects in six years of Fermi Large Area Telescope data. We found no significant excesses of gamma-ray emission. Under the assumption that the DES candidates are dSphs with dark matter halo properties similar to the known dSphs, we computed individual and combined limits on the velocity-averaged dark matter annihilation cross section for these new targets. If confirmed, they will constrain the annihilation cross section to lie below the thermal relic cross section for dark matter particles with masses < 20 GeV annihilating via the b-bbar or tau+tau- channels.

:,; Albert, A; Bechtol, K; Wood, M; Strigari, L; Sanchez-Conde, M; Baldini, L; Essig, R; Cohen-Tanugi, J; Anderson, B; Bellazzini, R; Bloom, E D; Caputo, R; Cecchi, C; Charles, E; Chiang, J; Conrad, J; de Angelis, A; Funk, S; Fusco, P; Gargano, F; Giglietto, N; Giordano, F; Guiriec, S; Gustafsson, M; Kuss, M; Loparco, F; Lubrano, P; Mirabal, N; Mizuno, T; Morselli, A; Ohsugi, T; Orlando, E; Persic, M; Raino, S; Spada, F; Suson, D J; Zaharijas, G; Zimmer, S; Abbott, T; Allam, S; Balbinot, E; Bauer, A H; Benoit-Levy, A; Bernstein, R A; Bernstein, G M; Bertin, E; Brooks, D; Buckley-Geer, E; Burke, D L; Rosell, A Carnero; Castander, F J; Covarrubias, R; D'Andrea, C B; da Costa, L N; DePoy, D L; Desai, S; Diehl, H T; Cunha, C E; Eifler, T F; Estrada, J; Evrard, A E; Neto, A Fausti; Fernandez, E; Finley, D A; Flaugher, B; Frieman, J; Gaztanaga, E; Gerdes, D; Gruen, D; Gruendl, R A; Gutierrez, G; Honscheid, K; Jain, B; James, D; Jeltema, T; Kent, S; Kron, R; Kuropatkin, N; Lahav, O; Li, T S; Luque, E; Maia, M A G; Makler, M; March, M; Marshall, J; Martini, P; Merritt, K W; Miller, C; Miquel, R; Mohr, J; Neilsen, E; Nord, B; Ogando, R; Peoples, J; Petravick, D; Pieres, A; Plazas, A A; Queiroz, A; Romer, A K; Roodman, A; Rykoff, E S; Sako, M; Sanchez, E; Santiago, B; Scarpine, V; Schubnell, M; Sevilla, I; Smith, R C; Soares-Santos, M; Sobreira, F; Suchyta, E; Swanson, M E C; Tarle, G; Thaler, J; Thomas, D; Tucker, D; Walker, A; Wechsler, R H; Wester, W; Williams, P; Yanny, B; Zuntz, J

2015-01-01T23:59:59.000Z

316

Confronting recent AMS-02 positron fraction and Fermi-LAT Extragalactic Gamma-Ray Background measurements with gravitino dark matter  

E-Print Network [OSTI]

The positron fraction measured by the space-based detectors PAMELA, Fermi-LAT and AMS-02 presents anomalous behaviour as energy increase. In particular AMS-02 observations provide compelling evidence for a new source of positrons and electrons. Its origin is unknown, it can be non-exotic (e.g. pulsars), be dark matter or maybe a mixture. We prove the gravitino of R-parity violating supersymmetric models as this source. As the gravitino is a spin 3/2 particle, it offers particular decay channels. We compute the electron, positron and gamma-ray fluxes produced by each gravitino decay channel as it would be detected at the Earth's position. Combining the flux from the different decay modes we can fit AMS-02 measurements of the positron fraction, as well as the electron and positron fluxes, with a gravitino dark matter mass in the range $1-2$ TeV and lifetime of $\\sim 1.0-0.8\\times 10^{26}$ s. The high statistics measurement of electron and positron fluxes, and the flattering in the behaviour of the positron frac...

Carquin, Edson; Gomez-Vargas, German A; Panes, Boris; Viaux, Nicolas

2015-01-01T23:59:59.000Z

317

FIVE NEW MILLISECOND PULSARS FROM A RADIO SURVEY OF 14 UNIDENTIFIED FERMI-LAT GAMMA-RAY SOURCES  

SciTech Connect (OSTI)

We have discovered five millisecond pulsars (MSPs) in a survey of 14 unidentified Fermi Large Area Telescope sources in the southern sky using the Parkes radio telescope. PSRs J0101-6422, J1514-4946, and J1902-5105 reside in binaries, while PSRs J1658-5324 and J1747-4036 are isolated. Using an ephemeris derived from timing observations of PSR J0101-6422 (P = 2.57 ms, DM = 12 pc cm{sup -3}), we have detected {gamma}-ray pulsations and measured its proper motion. Its {gamma}-ray spectrum (a power law of {Gamma} = 0.9 with a cutoff at 1.6 GeV) and efficiency are typical of other MSPs, but its radio and {gamma}-ray light curves challenge simple geometric models of emission. The high success rate of this survey-enabled by selecting {gamma}-ray sources based on their detailed spectral characteristics-and other similarly successful searches indicate that a substantial fraction of the local population of MSPs may soon be known.

Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Johnson, T. J. [National Academy of Sciences, Washington, DC 20001 (United States); Ferrara, E. C.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Johnston, S.; Keith, M.; Reynolds, J. E. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping, NSW 1710 (Australia); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Ray, P. S.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Sarkissian, J., E-mail: kerrm@stanford.edu, E-mail: fernando@astro.columbia.edu, E-mail: tyrel.j.johnson@gmail.com [CSIRO Parkes Observatory, Parkes, NSW 2870 (Australia)

2012-03-20T23:59:59.000Z

318

High-Resolution Crack Imaging Reveals Degradation Processes in...  

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

Reveals Degradation Processes in Nuclear Reactor Structural Materials. Abstract: Corrosion and cracking represent critical failure mechanisms for structural materials in many...

319

Two Studies Reveal Details of Lithium-Battery Function  

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

Two Studies Reveal Details of Lithium-Battery Function Print Our way of life is deeply intertwined with battery technologies that have enabled a mobile revolution powering cell...

320

Comparative genomics reveals diversity among xanthomonads infecting tomato and pepper  

E-Print Network [OSTI]

Potnis et al. : Comparative genomics reveals diversity amongtomato and pepper. BMC Genomics Submit your next manuscriptpv. syringae Potnis et al. BMC Genomics 2011, 12:146 http://

2011-01-01T23:59:59.000Z

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321

Environmental Genomics Reveals a Single-Species Ecosystem Deep Earth  

E-Print Network [OSTI]

Environmental Genomics Reveals a Single-Species EcosystemTechnology Program, DOE Joint Genomics Institute, Berkeley,and Environmental Research, Genomics:GTL program through

Arkin, Adam P.

2014-01-01T23:59:59.000Z

322

analysis reveals complexity: Topics by E-print Network  

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

Ancient mitochondrial DNA analysis reveals complexity of indigenous North American turkey) Although the cultural and nutritive importance of the turkey (Meleagris gallopavo) to...

323

Global transcriptomic analysis of Cyanothece 51142 reveals robust...  

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

photosynthetic bacterium Citation: Stockel J, EA Welsh, ML Liberton, RV Kunnavakkam, R Aurora, and HB Pakrasi.2008."Global transcriptomic analysis of Cyanothece 51142 reveals...

324

A Revealing Look Inside Passive and Active DPF Regeneration...  

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

A Revealing Look Inside Passive and Active DPF Regeneration: In-Situ Optical Analysis of Ash Formation and Transport A Consortium to Optimize Lubricant and Diesel Engines for...

325

Rechargeable Heat Battery's Secret Revealed: Solar Energy Capture...  

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

Rechargeable Heat Battery Rechargeable Heat Battery's Secret Revealed Solar energy capture in chemical form makes it storable and transportable January 11, 2011 | Tags: Chemistry,...

326

ORNL research reveals new challenges for mercury cleanup | ornl...  

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

Jennifer Brouner Communications 865.241.0709 ORNL research reveals new challenges for mercury cleanup ORNL researchers are learning more about the microbial processes that convert...

327

Computer-based business simulations as revealers of cultural  

E-Print Network [OSTI]

EA 4272 Computer-based business simulations as revealers of cultural and learning differences;1 Computer-based business simulations as revealers of cultural and learning differences. The case of Business learning, learning modes, culture, computer-based business simulations, Egypt, France, Globalization

Paris-Sud XI, Université de

328

Structure of the Yeast DEAD Box Protein Mss116p Reveals Two Wedges that Crimp RNA  

SciTech Connect (OSTI)

The yeast DEAD box protein Mss116p is a general RNA chaperone that functions in mitochondrial group I and II intron splicing, translational activation, and RNA end processing. Here we determined high-resolution X-ray crystal structures of Mss116p complexed with an RNA oligonucleotide and ATP analogs AMP-PNP, ADP-BeF{sub 3}, or ADP-AlF{sub 4}{sup -}. The structures show the entire helicase core acting together with a functionally important C-terminal extension. In all structures, the helicase core is in a closed conformation with a wedge {alpha} helix bending RNA 3' of the central bound nucleotides, as in previous DEAD box protein structures. Notably, Mss116p's C-terminal extension also bends RNA 5' of the central nucleotides, resulting in RNA crimping. Despite reported functional differences, we observe few structural changes in ternary complexes with different ATP analogs. The structures constrain models of DEAD box protein function and reveal a strand separation mechanism in which a protein uses two wedges to act as a molecular crimper.

Del Campo, Mark; Lambowitz, Alan M.; (Texas)

2010-01-12T23:59:59.000Z

329

Flux and Photon Spectral Index Distributions of Fermi-LAT Blazars and Contribution to the Extragalactic Gamma-ray Background  

SciTech Connect (OSTI)

We present a determination of the distributions of gamma-ray flux - the so called LogN-LogS relation - and photon spectral index for the 352 blazars detected with a greater than approximately seven sigma detection threshold and located above {+-} 20{sup o} Galactic latitude by the Large Area Telescope of the Fermi Gamma-ray Space Telescope in its first year catalog. Because the flux detection threshold depends on the photon index, the observed raw distributions do not provide the true LogN-LogS counts or the true distribution of the photon index. We use the non-parametric methods developed by Efron and Petrosian to reconstruct the intrinsic distributions from the observed ones which account for the data truncations introduced by observational bias and includes the effects of the possible correlation among the two variables. We demonstrate the robustness of our procedures using a simulated data set of blazars and then apply these to the real data and find that for the population as a whole the intrinsic flux distribution can be represented by a broken power law of slopes -2.37 {+-} 0.13 and -1.70 {+-} 0.26, and the intrinsic photon index distribution can be represented by a Gaussian with mean 2.41 {+-} 0.13 and 1{sigma} width of 0.25 {+-} 0.03. We also find the intrinsic distributions for the sub-populations of BL Lac and FSRQs type blazars separately. We then calculate the contribution of blazars to the diffuse cosmic gamma-ray background radiation to be 28% {+-} 19%.

Singal, J.; /KIPAC, Menlo Park /SLAC /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /SLAC /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.; Ajello, M.; /KIPAC, Menlo Park /SLAC /Stanford U.

2011-12-09T23:59:59.000Z

330

Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope  

SciTech Connect (OSTI)

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power {dot E} = 3.5 x 10{sup 33} ergs s{sup -1} is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 {+-} 0.01 and 0.08 {+-} 0.02 wide, separated by 0.44 {+-} 0.02 in phase. The first gamma-ray peak falls 0.15 {+-} 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 {+-} 1.05 {+-} 1.35) x 10{sup -8} cm{sup -2} s{sup -1} with cut-off energy (1.7 {+-} 0.4 {+-} 0.5) GeV. Based on its parallax distance of (300 {+-} 90) pc, we obtain a gamma-ray efficiency L{sub {gamma}}/{dot E} {approx_equal} 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M. /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, M.; /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U.; /more authors..

2011-11-17T23:59:59.000Z

331

THE FERMI-GBM X-RAY BURST MONITOR: THERMONUCLEAR BURSTS FROM 4U 0614+09  

SciTech Connect (OSTI)

Thermonuclear bursts from slowly accreting neutron stars (NSs) have proven difficult to detect, yet they are potential probes of the thermal properties of the NS interior. During the first year of a systematic all-sky search for X-ray bursts using the Gamma-ray Burst Monitor aboard the Fermi Gamma-ray Space Telescope we have detected 15 thermonuclear bursts from the NS low-mass X-ray binary 4U 0614+09 when it was accreting at nearly 1% of the Eddington limit. We measured an average burst recurrence time of 12 {+-} 3 days (68% confidence interval) between 2010 March and 2011 March, classified all bursts as normal duration bursts and placed a lower limit on the recurrence time of long/intermediate bursts of 62 days (95% confidence level). We discuss how observations of thermonuclear bursts in the hard X-ray band compare to pointed soft X-ray observations and quantify such bandpass effects on measurements of burst radiated energy and duration. We put our results for 4U 0614+09 in the context of other bursters and briefly discuss the constraints on ignition models. Interestingly, we find that the burst energies in 4U 0614+09 are on average between those of normal duration bursts and those measured in long/intermediate bursts. Such a continuous distribution in burst energy provides a new observational link between normal and long/intermediate bursts. We suggest that the apparent bimodal distribution that defined normal and long/intermediate duration bursts during the last decade could be due to an observational bias toward detecting only the longest and most energetic bursts from slowly accreting NSs.

Linares, M.; Chakrabarty, D. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Connaughton, V.; Bhat, P. N.; Briggs, M. S.; Preece, R. [CSPAR and Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Jenke, P.; Kouveliotou, C.; Wilson-Hodge, C. A. [Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Van der Horst, A. J. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, NL-1090-GE Amsterdam (Netherlands); Camero-Arranz, A.; Finger, M.; Paciesas, W. S. [Universities Space Research Association, Huntsville, AL 35805 (United States); Beklen, E. [Physics Department, Suleyman Demirel University, 32260 Isparta (Turkey); Von Kienlin, A. [Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, Postfach 1312, D-85748 Garching (Germany)

2012-12-01T23:59:59.000Z

332

SGR J1550-5418 BURSTS DETECTED WITH THE FERMI GAMMA-RAY BURST MONITOR DURING ITS MOST PROLIFIC ACTIVITY  

SciTech Connect (OSTI)

We have performed detailed temporal and time-integrated spectral analysis of 286 bursts from SGR J1550-5418 detected with the Fermi Gamma-ray Burst Monitor (GBM) in 2009 January, resulting in the largest uniform sample of temporal and spectral properties of SGR J1550-5418 bursts. We have used the combination of broadband and high time-resolution data provided with GBM to perform statistical studies for the source properties. We determine the durations, emission times, duty cycles, and rise times for all bursts, and find that they are typical of SGR bursts. We explore various models in our spectral analysis, and conclude that the spectra of SGR J1550-5418 bursts in the 8-200 keV band are equally well described by optically thin thermal bremsstrahlung (OTTB), a power law (PL) with an exponential cutoff (Comptonized model), and two blackbody (BB) functions (BB+BB). In the spectral fits with the Comptonized model, we find a mean PL index of -0.92, close to the OTTB index of -1. We show that there is an anti-correlation between the Comptonized E{sub peak} and the burst fluence and average flux. For the BB+BB fits, we find that the fluences and emission areas of the two BB functions are correlated. The low-temperature BB has an emission area comparable to the neutron star surface area, independent of the temperature, while the high-temperature BB has a much smaller area and shows an anti-correlation between emission area and temperature. We compare the properties of these bursts with bursts observed from other SGR sources during extreme activations, and discuss the implications of our results in the context of magnetar burst models.

Van der Horst, A. J.; Finger, M. H. [Universities Space Research Association, NSSTC, Huntsville, AL 35805 (United States); Kouveliotou, C. [Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Gorgone, N. M. [Connecticut College, New London, CT 06320 (United States); Kaneko, Y.; Goegues, E.; Lin, L. [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Guiriec, S.; Bhat, P. N.; Chaplin, V. L.; Goldstein, A. [University of Alabama, Huntsville, CSPAR, Huntsville, AL 35805 (United States); Granot, J. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Watts, A. L. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Bissaldi, E.; Gruber, D. [Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, Postfach 1312, 85748 Garching (Germany); Gehrels, N.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gibby, M. H.; Giles, M. M., E-mail: A.J.VanDerHorst@uva.nl [Jacobs Technology, Inc., Huntsville, AL (United States); and others

2012-04-20T23:59:59.000Z

333

GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS  

SciTech Connect (OSTI)

GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began {approx}13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10{sup 5} s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen {approx}30% of bursts with optical afterglows that live longer than 10{sup 5} s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A. [Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Maxham, A.; Zhang, B. B.; Zhang, B. [University of Nevada, Las Vegas, Box 454002, 4505 Maryland Parkway, Las Vegas, NV 89154 (United States); Schady, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Holland, S. T. [Universities Space Research Association, 10227 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States); Kuin, N. P. M.; Oates, S. R.; De Pasquale, M. [The UCL Mullard Space Science Laboratory, Holmbury St Mary, Surrey, RH5 6NT (United Kingdom); Page, K. L., E-mail: cswenson@astro.psu.ed [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

2010-07-20T23:59:59.000Z

334

MULTIWAVELENGTH OBSERVATIONS OF THE AGN 1ES 0414+009 WITH VERITAS, FERMI-LAT, SWIFT-XRT, AND MDM  

SciTech Connect (OSTI)

We present observations of the BL Lac object 1ES 0414+009 in the >200 GeV gamma-ray band by the VERITAS array of Cherenkov telescopes. 1ES 0414+009 was observed by VERITAS between 2008 January and 2011 February, resulting in 56.2 hr of good quality pointed observations. These observations resulted in a detection of 822 events from the source corresponding to a statistical significance of 6.4 standard deviations (6.4{sigma}) above the background. The source flux, showing no evidence for variability, is measured as (5.2 {+-} 1.1{sub stat} {+-} 2.6{sub sys}) Multiplication-Sign 10{sup -12} photons cm{sup -2} s{sup -1} above 200 GeV, equivalent to approximately 2% of the Crab Nebula flux above this energy. The differential photon spectrum from 230 GeV to 850 GeV is well fit by a power law with a photon index of {Gamma} = 3.4 {+-} 0.5{sub stat} {+-} 0.3{sub sys} and a flux normalization of (1.6 {+-} 0.3{sub stat} {+-} 0.8{sub sys}) Multiplication-Sign 10{sup -11} photons cm{sup -2} s{sup -1} at 300 GeV. We also present multiwavelength results taken in the optical (MDM), x-ray (Swift-XRT), and GeV (Fermi-LAT) bands and use these results to construct a broadband spectral energy distribution (SED). Modeling of this SED indicates that homogenous one-zone leptonic scenarios are not adequate to describe emission from the system, with a lepto-hadronic model providing a better fit to the data.

Aliu, E.; Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T.; Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Boettcher, M. [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Cannon, A.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Falcone, A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Federici, S., E-mail: aw.smith@utah.edu [DESY, Platanenallee 6, 15738 Zeuthen (Germany); and others

2012-08-20T23:59:59.000Z

335

Molecular Structure of Water at Gold Electrodes Revealed  

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

Molecular Structure of Water at Gold Electrodes Revealed Print The structure of liquid water has been intensely studied, but until recently, it has not been clear what happens to...

336

Comparative genomics reveals evidence of marine adaptation in Salinispora species.  

E-Print Network [OSTI]

Orcutt B, et al: Ecological genomics of marine roseobacters.1037-1042. Penn and Jensen BMC Genomics 2012, 13:86 http://and Jensen: Comparative genomics reveals evidence of marine

Penn, Kevin; Jensen, Paul R

2012-01-01T23:59:59.000Z

337

amyloid fibrils revealed: Topics by E-print Network  

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

22 23 24 25 Next Page Last Page Topic Index 1 Intrinsic Linear Heterogeneity of Amyloid Beta Protein Fibrils Revealed by Higher Resolution Mass-per-length Determinations* Chemistry...

338

amyloid fibrils reveals: Topics by E-print Network  

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

22 23 24 25 Next Page Last Page Topic Index 1 Intrinsic Linear Heterogeneity of Amyloid Beta Protein Fibrils Revealed by Higher Resolution Mass-per-length Determinations* Chemistry...

339

Alternate States of Proteins Revealed by Detailed Energy Landscape Mapping  

E-Print Network [OSTI]

Alternate States of Proteins Revealed by Detailed Energy Landscape Mapping Michael D. Tyka1 Keywords: Rosetta; alternative conformations; protein mobility; structure prediction; validation What through analysis of detailed protein energy landscapes generated by large-scale, native- enhanced sampling

Baker, David

340

analysis reveals potential: Topics by E-print Network  

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

Last Page Topic Index 1 Genetic Analysis in Populus Reveals Potential to Enhance Soil Carbon Sequestration In a paper published in the August, 2005 issue of Canadian Journal of...

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341

analysis reveals absence: Topics by E-print Network  

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

both in the Galactic disk and the Magellanic Clouds. Letizia Stanghellini 2007-09-19 19 Maximum-entropy network analysis reveals a role for tumor necrosis factor in peripheral...

342

Fermi-level depinning and contact resistance reduction in metal/n-Ge junctions by insertion of W-encapsulating Si cluster films  

SciTech Connect (OSTI)

We demonstrate Fermi-level depinning in metal/Ge junctions and a significant reduction of specific contact resistivity of n-Ge by inserting an ultra-thin semiconducting Si-rich W silicide film (WSi{sub n}, n?=?12–14) composed of W-encapsulating Si clusters. Dependence of the specific contact resistivity on the electron Schottky barrier height followed the ideal exponential relation for various contact metal species. This result indicates that the insertion of the WSi{sub n} film provides a negligible contribution to contact resistivity because its tunneling resistance is very low owing to the low offset of the conduction band edge of Ge.

Okada, Naoya [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562 (Japan); Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Uchida, Noriyuki [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562 (Japan); Kanayama, Toshihiko [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

2014-02-10T23:59:59.000Z

343

Resonance theory of the crossover from Bardeen-Cooper-Schrieffer superfluidity to Bose-Einstein condensation in a dilute Fermi gas  

E-Print Network [OSTI]

We present a description of the behavior of a superfluid gas of fermions in the presence of a Feshbach resonance over the complete range of magnetic field detunings. Starting from a resonance Hamiltonian, we exploit a functional method to describe the continuous behavior from Bardeen-Cooper-Schrieffer to Bose-Einstein condensation type superfluidity. Our results show an ability for a resonance system to exhibit a high critical temperature comparable to the Fermi temperature. The results are derived in a manner that is shown to be consistent with the underlying microscopic scattering physics.

J. N. Milstein; S. J. J. M. F. Kokkelmans; M. J. Holland

2002-07-18T23:59:59.000Z

344

Strongly interacting Fermi gases  

E-Print Network [OSTI]

Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision ...

Bakr, W.

345

Fermi Site Office Jobs  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 Industrial CarbonArticles News(SC) CCIScatteringFacilitiesU.S. DOE

346

Fermi National Accelerator Laboratory  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility of SF(STEO) ď‚·diffractive imaging withDots) -08

347

Fermi National Accelerator Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility of SF(STEO) ď‚·diffractive imaging withDots) -0810

348

Fermi National Accelerator Laboratory  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility of SF(STEO) ď‚·diffractive imaging withDots) -08103,

349

FermiNews  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility of SF(STEO) ď‚·diffractive imaging08 AFermi SiteNews

350

Enrico Fermi Patents  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia NanoparticlesSmartAffects the Future EnergyEnolSpectrometryEnrico

351

Fermi National Accelerator Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:Epitaxial ThinFORFALL NEWSFemtosecond X-ray4, Fermilab spent

352

Enrico Fermi - Hanford Site  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home It isGas SeparationsRelevant to

353

GMRT DISCOVERY OF PSR J1544+4937: AN ECLIPSING BLACK-WIDOW PULSAR IDENTIFIED WITH A FERMI-LAT SOURCE  

SciTech Connect (OSTI)

Using the Giant Metrewave Radio Telescope, we performed deep observations to search for radio pulsations in the directions of unidentified Fermi-Large Area Telescope {gamma}-ray sources. We report the discovery of an eclipsing black-widow millisecond pulsar, PSR J1544+4937, identified with the uncataloged {gamma}-ray source FERMI J1544.2+4941. This 2.16 ms pulsar is in a 2.9 hr compact circular orbit with a very low mass companion (M{sub c} > 0.017M{sub Sun }). At 322 MHz this pulsar is found to be eclipsing for 13% of its orbit, whereas at 607 MHz the pulsar is detected throughout the low-frequency eclipse phase. Variations in the eclipse ingress phase are observed, indicating a clumpy and variable eclipsing medium. Moreover, additional short-duration absorption events are observed around the eclipse boundaries. Using the radio timing ephemeris we were able to detect {gamma}-ray pulsations from this pulsar, confirming it as the source powering the {gamma}-ray emission.

Bhattacharyya, B.; Roy, J.; Gupta, Y. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Ray, P. S.; Wolff, M. T.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Bhattacharya, D. [Inter-University Centre for Astronomy and Astrophysics, Pune 411 007 (India); Romani, R. W.; Den Hartog, P. R.; Kerr, M.; Michelson, P. F. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Ferrara, E. C.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Cognard, I. [Laboratoire de Physique et Chimie de l'Environnement, LPCE UMR 6115 CNRS, F-45071 Orleans Cedex 02 (France); Johnston, S.; Keith, M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping, NSW 1710 (Australia); Saz Parkinson, P. M. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Wood, D. L. [Praxis Inc., Alexandria, VA 22303 (United States)

2013-08-10T23:59:59.000Z

354

High-Energy Gamma-Ray Emission From Solar Flares: Summary of Fermi LAT Detections and Analysis of Two M-Class Flares  

E-Print Network [OSTI]

We present the detections of 19 solar flares detected in high-energy gamma rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first four years of operation. Interestingly, all flares are associated with fairly fast Coronal Mass Ejections (CMEs) and are not all powerful X-ray flares. We then describe the detailed temporal, spatial and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying gamma-ray emission over 13 hours, and the 2011 June 7 M2.5 flare, which was followed by gamma-ray emission lasting for 2 hours. We compare the Fermi-LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that a hadronic origin of the gamma rays is more likely than a leptonic origin and find that the energy spectrum of the proton distribution softens after the 2011 March 7 flare, favoring a scenario with continuous acceleration at the flare site. This work suggests that proton acceleratio...

,

2013-01-01T23:59:59.000Z

355

Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre  

SciTech Connect (OSTI)

We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E{sub ?} = 130 GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess originates from. Our best optimized fit is obtained for the central region of Galaxy with a clear peak at 130 GeV with local statistical significance 4.5?. The observed excess is not correlated with Fermi bubbles. We compute the photon spectra induced by dark matter annihilations into two and four standard model particles, the latter via two light intermediate states, and fit the spectra with data. Since our fits indicate sharper and higher signal peak than in the previous works, data favors dark matter direct two-body annihilation channels into photons or other channels giving only line-like spectra. If Einasto halo profile correctly predicts the central cusp of Galaxy, dark matter annihilation cross-section to two photons is of order ten percent of the standard thermal freeze-out cross-section. The large dark matter two-body annihilation cross-section to photons may signal a new resonance that should be searched for at the CERN LHC experiments.

Tempel, Elmo; Hektor, Andi; Raidal, Martti, E-mail: elmo@aai.ee, E-mail: andi.hektor@cern.ch, E-mail: martti.raidal@cern.ch [NICPB, Ravala 10, Tallinn 10143 (Estonia)

2012-09-01T23:59:59.000Z

356

Study of luminosity and spin-up relation in X-ray binary pulsars with long-term monitoring by MAXI/GSC and Fermi/GBM  

E-Print Network [OSTI]

We study the relation between luminosity and spin-period change in X-ray binary pulsars using long-term light curve obtained by the MAXI/GSC all-sky survey and pulse period data from the Fermi/GBM pulsar project. X-ray binaries, consisting of a highly magnetized neutron star and a stellar companion, originate X-ray emission according to the energy of the accretion matter onto the neutron star. The accretion matter also transfers the angular momentum at the Alfven radius, and then spin up the neutron star. Therefore, the X-ray luminosity and the spin-up rate are supposed to be well correlated. We analyzed the luminosity and period-change relation using the data taken by continuous monitoring of MAXI/GSC and Fermi/GBM for Be/X-ray binaries, GX 304$-$1, A 0535$+$26, GRO J1008$-$57, KS 1947$+$300, and 2S 1417$-$624, which occurred large outbursts in the last four years. We discuss the results comparing the obtained observed relation with that of the theoretical model by Ghosh \\& Lamb (1979).

Sugizaki, Mutsumi; Nakajima, Motoki; Yamaoka, Kazutaka

2015-01-01T23:59:59.000Z

357

The Aquila prestellar core population revealed by Herschel  

E-Print Network [OSTI]

The origin and possible universality of the stellar initial mass function (IMF) is a major issue in astrophysics. One of the main objectives of the Herschel Gould Belt Survey is to clarify the link between the prestellar core mass function (CMF) and the IMF. We present and discuss the core mass function derived from Herschel data for the large population of prestellar cores discovered with SPIRE and PACS in the Aquila Rift cloud complex at d ~ 260 pc. We detect a total of 541 starless cores in the entire ~11 deg^2 area of the field imaged at 70-500 micron with SPIRE/PACS. Most of these cores appear to be gravitationally bound, and thus prestellar in nature. Our Herschel results confirm that the shape of the prestellar CMF resembles the stellar IMF, with much higher quality statistics than earlier submillimeter continuum ground-based surveys.

Könyves, V; Men'shchikov, A; Schneider, N; Arzoumanian, D; Bontemps, S; Attard, M; Motte, F; Didelon, P; Maury, A; Abergel, A; Ali, B; Baluteau, J -P; Bernard, J -Ph; Cambrésy, L; Cox, P; Di Francesco, J; di Giorgio, A M; Griffin, M J; Hargrave, P; Huang, M; Kirk, J; Li, J Z; Martin, P; Minier, V; Molinari, S; Olofsson, G; Pezzuto, S; Russeil, D; Roussel, H; Saraceno, P; Sauvage, M; Sibthorpe, B; Spinoglio, L; Testi, L; Ward-Thompson, D; White, G; Wilson, C D; Woodcraft, A; Zavagno, A

2010-01-01T23:59:59.000Z

358

ALS Capabilities Reveal How Like Can Attract Like  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS Capabilities RevealALS

359

The surface-state of the topological insulator Bi2Se3 revealed by cyclotron resonance  

SciTech Connect (OSTI)

Transport measurements of topological insulators are dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and microwave-spectroscopy to selectively couple to the surface conductivity of Bi2Se3 at high frequency. In the frequency range of a few GHz we observe a crossover from quantum oscillations indicative of a small 3D Fermi surface, to cyclotron resonance indicative of a 2D surface state. By probing the conductivity at reduced skin depths, we have observed a 2D cyclotron resonance from a material whose bulk Fermi-surface is 3D. The frequency-magnetic field scaling of this resonance is inconsistent with the bulk effective mass, but more consistent with the dispersion and band filling of a Dirac-like surface state as observed by ARPES, with substantial manybody renormalization.

Mcdonald, Ross D [Los Alamos National Laboratory; Ayala - Valenzuela, Oscar E [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Analytis, James G [STANFORD UNIV/SLAC; Chu, J. H. [STANFORD UNIV/SLAC; Fisher, R. [STANFORD UNIV/SLAC

2011-01-14T23:59:59.000Z

360

Revised FINAL–REPORT NO. 2: INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE ENRICO FERMI ATOMIC POWER PLANT, UNIT 1, NEWPORT, MICHIGAN (DOCKET NO. 50 16; RFTA 10-004) 2018-SR-02-1  

SciTech Connect (OSTI)

The Enrico Fermi Atomic Power Plant, Unit 1 (Fermi 1) was a fast breeder reactor design that was cooled by sodium and operated at essentially atmospheric pressure. On May 10, 1963, the Atomic Energy Commission (AEC) granted an operating license, DPR-9, to the Power Reactor Development Company (PRDC), a consortium specifically formed to own and operate a nuclear reactor at the Fermi 1 site. The reactor was designed for a maximum capability of 430 megawatts (MW); however, the maximum reactor power with the first core loading (Core A) was 200 MW. The primary system was filled with sodium in December 1960 and criticality was achieved in August 1963. The reactor was tested at low power during the first couple years of operation. Power ascension testing above 1 MW commenced in December 1965 immediately following the receipt of a high-power operating license. In October 1966 during power ascension, zirconium plates at the bottom of the reactor vessel became loose and blocked sodium coolant flow to some fuel subassemblies. Two subassemblies started to melt and the reactor was manually shut down. No abnormal releases to the environment occurred. Forty-two months later after the cause had been determined, cleanup completed, and the fuel replaced, Fermi 1 was restarted. However, in November 1972, PRDC made the decision to decommission Fermi 1 as the core was approaching its burn-up limit. The fuel and blanket subassemblies were shipped off-site in 1973. Following that, the secondary sodium system was drained and sent off-site. The radioactive primary sodium was stored on-site in storage tanks and 55 gallon (gal) drums until it was shipped off-site in 1984. The initial decommissioning of Fermi 1 was completed in 1975. Effective January 23, 1976, DPR-9 was transferred to the Detroit Edison Company (DTE) as a 'possession only' license (DTE 2010a). This report details the confirmatory activities performed during the second Oak Ridge Institute for Science and Education (ORISE) site visit to Fermi 1 in November 2010. The survey was strategically planned during a Unit 2 (Fermi 2) outage to take advantage of decreased radiation levels that were observed and attributed to Fermi 2 from the operating unit during the first site visit. However, during the second visit there were elevated radiation levels observed and attributed to the partially dismantled Fermi 1 reactor vessel and a waste storage box located on the 3rd floor of the Fermi 1 Turbine Building. Confirmatory surveys (unshielded) performed directly in the line of sight of these areas were affected. The objective of the confirmatory survey was to verify that the final radiological conditions were accurately and adequately described in Final Status Survey (FSS) documentation, relative to the established release criteria. This objective was achieved by performing document reviews, as well as independent measurements and sampling. Specifically, documentation of the planning, implementation, and results of the FSS were evaluated; side-by-side FSS measurement and source comparisons were performed; site areas were evaluated relative to appropriate FSS classification; and areas were assessed for residual, undocumented contamination.

Erika Bailey

2011-10-27T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" from the National Library of EnergyBeta (NLEBeta).
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361

HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES,  

E-Print Network [OSTI]

-1- HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES, CARTHAGE, December, 2001 Manuscript # 01066 LAUR# 01-1204 #12;Hydraulic Stimulation of Natural Fractures -2- ABSTRACT We have produced a high-resolution microseismic image of a hydraulic fracture stimulation

362

COMBINING STATED AND REVEALED CHOICE RESEARCH TO INFORM ENERGY SYSTEM  

E-Print Network [OSTI]

Energy System Simulation Models: The Case of Hybrid Electric Vehicles Report Number: 409 ExaminingCOMBINING STATED AND REVEALED CHOICE RESEARCH TO INFORM ENERGY SYSTEM SIMULATION MODELS: THE CASE parameters for a hybrid energy-economy model (called CIMS) using empirically derived choice models based

363

Wednesday, March 14, 2007 STARDUST: WILD-2 REVEALED  

E-Print Network [OSTI]

Wednesday, March 14, 2007 STARDUST: WILD-2 REVEALED 8:30 a.m. Marina Plaza Ballroom Chairs: F. J of Comet Wild 2 Particles Extracted from Stardust Aerogel [#1126] TOF-SIMS of seven cometary fragments from observed for individual particles, the average composition is close to CI that seems to represent bulk Wild

Rathbun, Julie A.

364

DYNAMIC INVARIANTS IN PROTEIN FOLDING PATHWAYS REVEALED BY TENSOR ANALYSIS  

E-Print Network [OSTI]

DYNAMIC INVARIANTS IN PROTEIN FOLDING PATHWAYS REVEALED BY TENSOR ANALYSIS Arvind Ramanathan Lane a spatio-temporal analysis of protein folding pathways. We applied our method to folding simulations of how a protein folds into its functionally relevant conformations. Protein folding pathways span over

Langmead, Christopher James

365

Historical forest baselines reveal potential for continued carbon sequestration  

E-Print Network [OSTI]

Historical forest baselines reveal potential for continued carbon sequestration Jeanine M-based studies suggest that land-use history is a more important driver of carbon sequestration in these systems agricultural lands are being promoted as important avenues for future carbon sequestration (8). But the degree

Mladenoff, David

366

Real-Time Redox Measurements during Endoplasmic Reticulum Stress Reveal  

E-Print Network [OSTI]

Real-Time Redox Measurements during Endoplasmic Reticulum Stress Reveal Interlinked Protein Folding.10.011 SUMMARY Disruption of protein folding in the endoplasmic reticulum (ER) causes unfolded proteins to accumu is active. Because ER redox po- tential is optimized for oxidative protein folding, we reasoned

Mullins, Dyche

367

CONSTRAINTS ON COSMIC RAYS, MAGNETIC FIELDS, AND DARK MATTER FROM GAMMA-RAY OBSERVATIONS OF THE COMA CLUSTER OF GALAXIES WITH VERITAS AND FERMI  

SciTech Connect (OSTI)

Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order of (2-5) Multiplication-Sign 10{sup -8} photons m {sup -2} s {sup -1} (VERITAS, >220 GeV) and {approx}2 Multiplication-Sign 10{sup -6} photons m {sup -2} s {sup -1} (Fermi, 1-3 GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be <16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of {approx}(2-5.5) {mu}G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, ({sigma}v).

Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T.; Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Byrum, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Cannon, A.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W.; Feng, Q.; Finley, J. P. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Falcone, A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Federici, S., E-mail: pohlmadq@gmail.com, E-mail: christoph.pfrommer@h-its.org [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); and others

2012-10-01T23:59:59.000Z

368

Il Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" of-fre la possibilit a giovani ricercatori di svolgere la loro a vit in se ori  

E-Print Network [OSTI]

'uomo e all'energia. Nel se ore dell'energia il Centro Fermi ha dedicato uno dei propri proge strategici basano sul concentratore solare sviluppato u lizzando tecnologie mature derivan dal se ore automobili &ENERGIA AttivitĂ  editoriale a cura de Il Sole 24 ORE Business Media LO SCENARIO / I risultati del rapporto

369

Measurement of the Cosmic Ray e+ plus e- Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope  

SciTech Connect (OSTI)

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m{sup 2}sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply-falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E{sup -3.0} and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, M.; /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bogaert, G.; /Ecole Polytechnique; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /Stockholm U., OKC /Royal Inst. Tech., Stockholm /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Pisa /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Bari U. /INFN, Bari; /more authors..

2012-05-14T23:59:59.000Z

370

Fermi/LAT Study of the Cygnus Loop Supernova Remnant: Discovery of a Point-like Source and of Spectral Differences in its gamma-ray emission  

E-Print Network [OSTI]

The Cygnus Loop is a nearby supernova remnant (SNR) observed across the electromagnetic spectrum. With the analysis of 6 years of Fermi/LAT data we find that, what previous studies had considered a single source, consists of an extended source plus a point-like source south-east of the SNR. The extended gamma-ray emission is well correlated with the thermal X-ray emission of the SNR, and the energy spectrum displays a pronounced maximum at $\\sim0.6$\\,GeV. However, in a region where the radio emission is strongly and distinctly polarized, the gamma-ray spectrum shows no sign of a break. Therefore, the spatially resolved gamma-ray emission permits the study of different interaction conditions of the SNR and the surrounding medium.

Reichardt, I; West, J; Safi-Harb, S; de Ońa-Wilhelmi, E; Rico, J

2015-01-01T23:59:59.000Z

371

Demonstrating 1 nm-oxide-equivalent-thickness HfO{sub 2}/InSb structure with unpinning Fermi level and low gate leakage current density  

SciTech Connect (OSTI)

In this work, the band alignment, interface, and electrical characteristics of HfO{sub 2}/InSb metal-oxide-semiconductor structure have been investigated. By using x-ray photoelectron spectroscopy analysis, the conduction band offset of 1.78 ± 0.1 eV and valence band offset of 3.35 ± 0.1 eV have been extracted. The transmission electron microscopy analysis has shown that HfO{sub 2} layer would be a good diffusion barrier for InSb. As a result, 1 nm equivalent-oxide-thickness in the 4 nm HfO{sub 2}/InSb structure has been demonstrated with unpinning Fermi level and low leakage current of 10{sup ?4} A/cm{sup ?2}. The D{sub it} value of smaller than 10{sup 12} eV{sup ?1}cm{sup ?2} has been obtained using conduction method.

Trinh, Hai-Dang [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Lin, Yueh-Chin; Nguyen, Hong-Quan; Luc, Quang-Ho [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China)] [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Nguyen, Minh-Thuy; Duong, Quoc-Van; Nguyen, Manh-Nghia [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)] [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Wang, Shin-Yuan [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)] [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China); Yi Chang, Edward [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)

2013-09-30T23:59:59.000Z

372

Enrico Fermi Awards Ceremony for Dr. Allen J. Bard and Dr. Andrew Sessler, February 2014 (Presentations, including remarks by Energy Secretary, Dr. Ernest Moniz)  

ScienceCinema (OSTI)

The Fermi Award is a Presidential award and is one of the oldest and most prestigious science and technology honors bestowed by the U.S. Government. On February 3, 2014 it was conferred upon two exceptional scientists. The first to be recognized is Dr. Allen J. Bard, 'for international leadership in electrochemical science and technology, for advances in photoelectrochemistry and photocatalytic materials, processes, and devices, and for discovery and development of electrochemical methods including electrogenerated chemiluminescence and scanning electrochemical microscopy.' The other honoree is Dr. Andrew Sessler, 'for advancing accelerators as powerful tools of scientific discovery, for visionary direction of the research enterprise focused on challenges in energy and the environment, and for championing outreach and freedom of scientific inquiry worldwide.' Dr. Patricia Dehmer opened the ceremony, and Dr. Ernest Moniz presented the awards.

Moniz, Ernest [U.S. Energy Secretary

2014-08-22T23:59:59.000Z

373

Enrico Fermi Awards Ceremony for Dr. Mildred S. Dresselhaus and Dr. Burton Richter, May 2012 (Presentations, including remarks by Energy Secretary, Dr. Steven Chu)  

ScienceCinema (OSTI)

The Fermi Award is a Presidential award and is one of the oldest and most prestigious science and technology honors bestowed by the U.S. Government. On May 7, 2012 it was conferred upon two exceptional scientists: Dr. Mildred Dresselhaus, 'for her scientific leadership, her major contributions to science and energy policy, her selfless work in science education and the advancement of diversity in the scientific workplace, and her highly original and impactful research,' and Dr. Burton Richter, 'for the breadth of his influence in the multiple disciplines of accelerator physics and particle physics, his profound scientific discoveries, his visionary leadership as SLAC Director, his leadership of science, and his notable contributions in energy and public policy.' Dr. John Holder, Director of the White House Office of Science and Technology Policy, opened the ceremony, and Dr. Bill Brinkman, Director of DOE's Office of Science introduced the main speaker, Dr. Steven Chu, U.S. Energy Secretary.

Chu, Steven (U.S. Energy Secretary)

2012-06-28T23:59:59.000Z

374

Fermi Guest Investigator Program Cycle 2 Project Final Report Albedo Polarimetry of Gamma-Ray Bursts and Solar Flares with GBM  

SciTech Connect (OSTI)

Several key properties of GRBs remain poorly understood and are difficult or even impossible to infer with the information currently being collected. Polarization measurements will probe the precise nature of the central engine. For solar flares, high-energy polarization measurements are expected to be useful in determining the beaming (or directivity) of solar flare electrons - a quantity that may provide important clues about electron acceleration and transport. We propose to investigate the viability of using the Fermi Gamma-ray Burst Monitor (GBM) to measure the polarization of GRBs and solar flares using the albedo photon flux. This approach was previously developed for use with BATSE data. We will conduct a careful study of this technique using a modified version of the GRESS simulation tools developed by the GBM team.

Kippen, Richard Marc [Los Alamos National Laboratory

2012-08-27T23:59:59.000Z

375

Obscure pulmonary masses: bronchial impaction revealed by CT  

SciTech Connect (OSTI)

Dilated bronchi impacted with mucus or tumor are recognized on standard chest radiographs because they are surrounded by aerated pulmonary parenchyma. When imaged in different projections, these lesions produce a variety of appearances that are generally familiar. This report characterizes less familiar computed tomographic (CT) findings in eight patients with pathologic bronchial distension of congenital, neoplastic, or infectious etiologies and correlates them with chest films. In seven patients, CT readily revealed dilated bronchi and/or regional lung hypodensity. In four of these cases, CT led to the initial suspicion of dilated bronchi. CT should be used early in the evaluation of atypical pulmonary mass lesions or to confirm suspected bronchial impaction because of the high probability it will reveal diagnostic features.

Pugatch, R.D.; Gale, M.E.

1983-11-01T23:59:59.000Z

376

GAMMA-RAY LOUDNESS, SYNCHROTRON PEAK FREQUENCY, AND PARSEC-SCALE PROPERTIES OF BLAZARS DETECTED BY THE FERMI LARGE AREA TELESCOPE  

SciTech Connect (OSTI)

The parsec-scale radio properties of 232 active galactic nuclei, most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA) at 5 GHz. Data from both the first 11 months (1FGL) and the first 2 years (2FGL) of the Fermi mission were used to investigate these sources' {gamma}-ray properties. We use the ratio of the {gamma}-ray-to-radio luminosity as a measure of {gamma}-ray loudness. We investigate the relationship of several radio properties to {gamma}-ray loudness and to the synchrotron peak frequency. There is a tentative correlation between {gamma}-ray loudness and synchrotron peak frequency for BL Lac objects in both 1FGL and 2FGL, and for flat-spectrum radio quasars (FSRQs) in 2FGL. We find that the apparent opening angle tentatively correlates with {gamma}-ray loudness for FSRQs, but only when we use the 2FGL data. We also find that the total VLBA flux density correlates with the synchrotron peak frequency for BL Lac objects and FSRQs. The core brightness temperature also correlates with synchrotron peak frequency, but only for the BL Lac objects. The low-synchrotron-peaked (LSP) BL Lac object sample shows indications of contamination by FSRQs which happen to have undetectable emission lines. There is evidence that the LSP BL Lac objects are more strongly beamed than the rest of the BL Lac object population.

Linford, J. D.; Taylor, G. B.; Schinzel, F. K., E-mail: jlinford@unm.edu [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131-0001 (United States)

2012-09-20T23:59:59.000Z

377

Transient light-induced intracellular oxidation revealed by redox biosensor  

SciTech Connect (OSTI)

Highlights: •Time-resolved live cell imaging revealed light-induced oxidation. •Only the roGFP probe fused with glutaredoxin reveals photooxidation. •The transient oxidation is rapidly reduced by the cytosolic antioxidant system. •Intracellular photooxidation is media-dependent. •Oxidation is triggered exclusively by exposure to short wavelength excitation. -- Abstract: We have implemented a ratiometric, genetically encoded redox-sensitive green fluorescent protein fused to human glutaredoxin (Grx1-roGFP2) to monitor real time intracellular glutathione redox potentials of mammalian cells. This probe enabled detection of media-dependent oxidation of the cytosol triggered by short wavelength excitation. The transient nature of light-induced oxidation was revealed by time-lapse live cell imaging when time intervals of less than 30 s were implemented. In contrast, transient ROS generation was not observed with the parental roGFP2 probe without Grx1, which exhibits slower thiol-disulfide exchange. These data demonstrate that the enhanced sensitivity of the Grx1-roGFP2 fusion protein enables the detection of short-lived ROS in living cells. The superior sensitivity of Grx1-roGFP2, however, also enhances responsiveness to environmental cues introducing a greater likelihood of false positive results during image acquisition.

Kolossov, Vladimir L., E-mail: viadimer@illinois.edu [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Beaudoin, Jessica N. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Hanafin, William P. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States)] [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); DiLiberto, Stephen J. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Kenis, Paul J.A. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801 (United States); Rex Gaskins, H. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 S. Lincoln Avenue, Urbana, IL 61801 (United States); Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 S. Goodwin Avenue, Urbana, IL 61801 (United States)

2013-10-04T23:59:59.000Z

378

Environmental genomics reveals a single species ecosystem deep within the Earth  

E-Print Network [OSTI]

Environmental genomics reveals a single species ecosystemMaterial for Environmental genomics reveals a single speciesTechnology Program, DOE Joint Genomics Institute, Berkeley,

Chivian, Dylan

2008-01-01T23:59:59.000Z

379

Chromatin landscaping in algae reveals novel regulation pathway for biofuels production  

E-Print Network [OSTI]

Chromatin landscaping in algae reveals novel regulationChromatin landscaping in algae reveals novel regulationis known about the algae lipid biosynthetic regulatory

Ngan, Chew Yee

2014-01-01T23:59:59.000Z

380

E-Print Network 3.0 - analysis reveals differential Sample Search...  

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

plasmas Summary: and turbulence spreading into linearly stable regions. Statistical analysis of the simulation data reveals self... reveal the process of laminar scalar...

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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

E-Print Network 3.0 - analysis reveals co-upregulation Sample...  

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

analysis, the technique selects a subset of properties that are most likely to reveal an error... code program analysis model machine classifier fault-revealing properties Figure...

382

Polarized X-Rays Reveal Molecular Alignment in Printed Electronics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic TheoryPlant 242-Z AmericiumandPolarized X-Rays Reveal

383

Revealing the Atomic Restructuring of Pt-Co Nanoparticles. | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 Resource Program September 2010 B O N N Eweb applicationRevealing

384

Two Studies Reveal Details of Lithium-Battery Function  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof Energy Two CompaniesTwo Studies Reveal Details of

385

Two Studies Reveal Details of Lithium-Battery Function  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof Energy Two CompaniesTwo Studies Reveal Details ofTwo

386

Skyrmion Behavior Revealed by Two X-Ray Studies  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlightsSeminarsSiliconSite Map TUNLSkyrmion Behavior Revealed

387

ALS Capabilities Reveal How Like Can Attract Like  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS Capabilities Reveal How

388

ALS Capabilities Reveal How Like Can Attract Like  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS Capabilities Reveal HowALS

389

ALS Capabilities Reveal How Like Can Attract Like  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS Capabilities Reveal

390

ALS Capabilities Reveal How Like Can Attract Like  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS Capabilities RevealALSALS

391

Comment on "A limit on the variation of the speed of light arising from quantum gravity effects" aka "Testing Einstein's special relativity with Fermi's short hard gamma-ray burst GRB090510"  

E-Print Network [OSTI]

Recently the Fermi GBM and LAT Collaborations reported their new observational data disfavoring quite a number of the quantum gravity theories, including the one suggesting the nonlinear (logarithmic) modification of a quantum wave equation. We show that the latter is still far from being ruled out: it is not only able to explain the new data but also its phenomenological implications turn out to be more vast (and more interesting) than one expected before.

Konstantin G. Zloshchastiev

2009-11-30T23:59:59.000Z

392

GeV Gamma-ray Emission Detected by Fermi-LAT Likely Associated with the Supernova Remnant Kesteven 41 in a Molecular Environment  

E-Print Network [OSTI]

Hadronic emission from supernova remnant (SNR)--molecular cloud (MC) association systems has been widely regarded as a probe of the shock accelerated cosmic protons. We here report on the detection of a $\\gamma$-ray emission source, with a significance of $24\\sigma$ in 0.2--300 GeV, projectively on the northwest of SNR Kesteven 41, using 5.6 yr Fermi-LAT observation data. The $3\\sigma$ error circle, 0.09 degree in radius, covers the 1720MHz OH maser and is essentially consistent with the location of the $V_{LSR}~-50 km/s $ MC with which the SNR interacts. The source emission has a power-law spectrum with a photon index $2.38\\pm0.03$ and a 0.2--300 GeV luminosity $~1.6*10^{36} erg /s$ at a distance 12 kpc. There is no radio pulsar in the $3\\sigma$ circle responsible for the high luminosity. While the inverse Compton scattering scenario would lead to a difficulty in the electron energy budget, the source emission can be naturally explained with the hadronic interaction between the relativistic protons accelerat...

Liu, Bing; Zhang, Xiao; Zhang, Gao-Yuan; Xing, Yi

2015-01-01T23:59:59.000Z

393

The mystery of spectral breaks: Lyman continuum absorption by photon-photon pair production in the Fermi GeV spectra of bright blazars  

E-Print Network [OSTI]

We reanalyze Fermi/LAT gamma-ray spectra of bright blazars with a higher photon statistics than in previous works and with new Pass 7 data representation. In the spectra of the brightest blazar 3C 454.3 and possibly of 4C +21.35 we detect breaks at 5 GeV (in the rest frame) associated with the photon-photon pair production absorption by He II Lyman continuum (LyC). We also detect confident breaks at 20 GeV associated with hydrogen LyC both in the individual spectra and in the stacked redshift-corrected spectrum of several bright blazars. The detected breaks in the stacked spectra univocally prove that they are associated with atomic ultraviolet emission features of the quasar broad-line region (BLR). The dominance of the absorption by hydrogen Ly complex over He II, rather small detected optical depth, and the break energy consistent with the head-on collisions with LyC photons imply that the gamma-ray emission site is located within the BLR, but most of the BLR emission comes from a flat disk-like structure ...

Stern, Boris E

2014-01-01T23:59:59.000Z

394

Band Structure Parameters and Fermi Resonances of Exciton-Polaritons in CsI and CsBr under Hydrostatic Pressure  

SciTech Connect (OSTI)

Most alkali halides crystallize in the fcc sodium chloride structure. In contrast, with the exception of CsF, the Cs-halides form the simple cubic cesium chloride (CsCl) structure at ambient conditions and they have a substantially different electronic structure than other alkali halides; in particular, they have several nearly degenerate electronic levels near the Brillouin zone center. Highly resolved Three-Photon Spectroscopy (TPS) measurements allow direct observation of the near band edge structure and, in the case of CsI, probe more states than one-photon techniques. A number of interesting phenomena, among them level repulsion (Fermi resonance), occur as these levels are tuned through one another by application of hydrostatic pressure. To the best of our knowledge, this has been observed for CsBr for the first time. Doubling the photon energy range compared to a previous publication [see Yoo et al. PRL 84, 3875 (2000)] allows direct observation of the n=1, 2 and 3 exciton-polariton members of the {Lambda}{sub 8}{sup -}-{Lambda}{sub 6}{sup +} transition in CsI and lets us establish unambiguous values for the bandgap (6.139 eV), binding energy (0.265 eV) and their pressure dependence up to 7 kbar. Similarly to CsI, the CsBr linewidth of the lowest {Lambda}{sub 4}{sup -} polariton (A) decreases upon compression.

Lipp, M J; Yoo, C H; Strachan, D; Daniels, W B

2005-11-29T23:59:59.000Z

395

Nonthermal Two Component Dark Matter Model for Fermi-LAT $\\gamma$-ray excess and 3.55 keV X-ray Line  

E-Print Network [OSTI]

A two component model of nonthermal dark matter is formulated to simultaneously explain the Fermi-LAT results indicating a $\\gamma$-ray excess observed from our Galactic Centre in the 1-3 GeV energy range and the detection of an X-ray line at 3.55 keV from extra galactic sources. Two additional Standard Model singlet scalar fields $S_2$ and $S_3$ are introduced. These fields couple among themselves and with the Standard Model Higgs doublet $H$. The interaction terms among the scalar fields, namely $H$, $S_2$ and $S_3$, are constrained by the application of a discrete $\\mathbb{Z}_2\\times \\mathbb{Z}^\\prime_2$ symmetry which breaks softly to a remnant $\\mathbb{Z}^{\\prime \\prime}_2$ symmetry. This residual discrete symmetry is then spontaneously broken through an MeV order vacuum expectation value $u$ of the singlet scalar field $S_3$. The resultant physical scalar spectrum has the Standard Model like Higgs as $\\chi_{{}_{{}_1}}$ with $M_{\\chi_{{}_{{}_1}}}\\sim 125$ GeV, a moderately heavy scalar $\\chi_{{}_{{}_2}}$...

Biswas, Anirban; Roy, Probir

2015-01-01T23:59:59.000Z

396

Rapid HIFU autofocusing using the entire MR-ARFI image  

SciTech Connect (OSTI)

Phase aberrations and attenuations caused by bone can defocus HIFU in the brain and organs behind the ribcage. To refocus the beam, MR-ARFI can be used to measure tissue displacements created by each element in the transducer, and optimize driving signal delays and amplitudes. We introduce a new MR-ARFI-based autofocusing method that requires many fewer image acquisitions than current methods. The method is validated in simulations of bone and brain HIFU transducers, and compared to a conventional method.

Grissom, William A.; Kaye, Elena; Pauly, Kim Butts; Zur, Yuval; Yeo, Desmond; Medan, Yoav; Davis, Cynthia [Biomedical Engineering, Vanderbilt University, Nashville, Tennessee (United States); Electrical Engineering, Stanford University, Stanford, California (United States); Radiology, Stanford University, Stanford, California (United States); GE Healthcare, Haifa (Israel); GE Global Research, Niskayuna, New York (United States); Biomedical Engineering, Technion IIT, Haifa (Israel); GE Global Research, Niskayuna, New York (United States)

2012-11-28T23:59:59.000Z

397

GROWTH CONDITIONS FOR ENTIRE FUNCTIONS WITH ONLY BOUNDED FATOU COMPONENTS  

E-Print Network [OSTI]

this conclusion, and showed that the best one can hope for is that the growth of f does not exceed order 1 time where the notation m(r, f) is used in that meaning. The order (f) and lower order (f) of f small. The function f(z) = z-1/2 sin z + z + a is of order 1/2, mean type, and if a is a sufficiently

Hinkkanen, Aimo

398

Title Geology of the Great Basin. Copyright Issue Entire Book  

National Nuclear Security Administration (NNSA)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartmentNationalRestart of the Reviewwill help prepareA Review ofGeographic

399

Valiron deficiencies of entire characteristic functions of finite order  

E-Print Network [OSTI]

V. Linnik and I. V. Ostrovskii, Decomposition of Random Variables and Vectors [in Russian]0 Nauka,. Moscow 0-972). I. P. Kamynin and I. V. Ostrovskii, nOn ...

2005-01-06T23:59:59.000Z

400

Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs  

SciTech Connect (OSTI)

Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. Both genomes have 21,000 protein genes and are intron rich, and B. natans exhibits unprecedented alternative splicing for a single-celled organism. Phylogenomic analyses and subcellular targeting predictions reveal extensive genetic and biochemical mosaicism, with both host- and endosymbiont-derived genes servicing the mitochondrion, the host cell cytosol, the plastid and the remnant endosymbiont cytosol of both algae. Mitochondrion-to-nucleus gene transfer still occurs in both organisms but plastid-to-nucleus and nucleomorph-to-nucleus transfers do not, which explains why a small residue of essential genes remains locked in each nucleomorph.

Curtis, Bruce A.; Tanifuji, Goro; Burki, Fabien; Gruber, Ansgar; Irimia, Manuuel; Maruyama, Shinichiro; Arias, Maria C.; Ball, Steven G.; Gile, Gillian H.; Hirakawa, Yoshihisa; Hopkins, Julia F.; Kuo, Alan; Rensing, Stefan A.; Schmutz, Jeremy; Symeonidi, Aikaterini; Elias, Marek; Eveleigh, Robert J. M.; Herman, Emily K.; Klute, Mary J.; Nakayama, Takuro; Obornik, Miroslav; Reyes-Prieto, Adrian; Armbrust, E. Virginia; Aves, Stephen J.; Beiko, Robert G.; Coutinho, Pedro; Dacks, Joel B.; Durnford, Dion G.; Fast, Naomi M.; Green, Beverley R.; Grisdale, Cameron J.; Hempel, Franziska; Henrissat, Bernard; Hoppner, Marc P.; Ishida, Ken-Ichiro; Kim, Eunsoo; Koreny, Ludek; Kroth, Peter G.; Liu, Yuan; Malik, Shehre-Banoo; Maier, Uwe G.; McRose, Darcy; Mock, Thomas; Neilson, Jonathan A. D.; Onodera, Naoko T.; Poole, Anthony M.; Pritham, Ellen J.; Richards, Thomas A.; Rocap, Gabrielle; Roy, Scott W.; Sarai, Chihiro; Schaack, Sarah; Shirato, Shu; Slamovits, Claudio H.; Spencer, Davie F.; Suzuki, Shigekatsu; Worden, Alexandra Z.; Zauner, Stefan; Barry, Kerrie; Bell, Callum; Bharti, Arvind K.; Crow, John A.; Grimwood, Jane; Kramer, Robin; Lindquist, Erika; Lucas, Susan; Salamov, Asaf; McFadden, Geoffrey I.; Lane, Christopher E.; Keeling, Patrick J.; Gray, Michael W.; Grigoriev, Igor V.; Archibald, John M.

2012-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "fermi reveals entire" 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

Topological Structure of the QCD Vacuum Revealed by Overlap Fermions  

E-Print Network [OSTI]

Overlap fermions preserve a remnant of chiral symmetry on the lattice. They are a powerful tool to investigate the topological structure of the vacuum of Yang-Mills theory and full QCD. Recent results concerning the localization of topological charge and the localization and local chirality of the overlap eigenmodes are reported. The charge distribution is radically different, if a spectral cut-off for the Dirac eigenmodes is applied. The density q(x) is changing from the scale-a charge density (with full lattice resolution) to the ultraviolet filtered charge density. The scale-a density, computed on the Linux cluster of LRZ, has a singular, sign-coherent global structure of co-dimension 1 first described by the Kentucky group. We stress, however, the cluster properties of the UV filtered topological density resembling the instanton picture. The spectral cut-off can be mapped to a bosonic smearing procedure. The UV filtered field strength reveals a high degree of (anti)selfduality at "hot spots" of the action. The fermionic eigenmodes show a high degree of local chirality. The lowest modes are seen to be localized in low-dimensional space-time regions.

E. -M. Ilgenfritz; K. Koller; Y. Koma; G. Schierholz; V. Weinberg

2010-03-15T23:59:59.000Z

402

Pushing Typists Back on the Learning Curve: Revealing Chunking in Skilled Typewriting  

E-Print Network [OSTI]

Pushing Typists Back on the Learning Curve: Revealing Chunking in Skilled Typewriting Motonori in perception, and Experiment 2 manip- ulated concurrent memory load to reveal chunking in short-term memory

Logan, Gordon D.

403

Structural genomics reveals EVE as a new ASCH/PUA-related domain...  

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

reveals EVE as a new ASCHPUA-related domain. Structural genomics reveals EVE as a new ASCHPUA-related domain. Abstract: We report on a number of proteins recently solved by NESG...

404

Genome analysis of Bifidobacterium bifidum PRL2010 reveals metabolic pathways for host-derived  

E-Print Network [OSTI]

Genome analysis of Bifidobacterium bifidum PRL2010 reveals metabolic pathways for host,214,650-bp genome of Bifidobacterium bifidum PRL2010, a strain isolated from infant stool, revealed

Gleeson, Joseph G.

405

Downstream genes of Pax6 revealed by comprehensive transcriptome profiling in the developing rat hindbrain  

E-Print Network [OSTI]

C: A screen for downstream effectors of Neurogenin2 in theNumayama-Tsuruta et al. : Downstream genes of Pax6 revealedARTICLE Open Access Downstream genes of Pax6 revealed by

2010-01-01T23:59:59.000Z

406

Functional Connectivity Magnetic Resonance Imaging Reveals Cortical Functional Connectivity in the Developing Brain  

E-Print Network [OSTI]

in the Developing Brain Weili Lin, Ph.D.^1 , Quan Zhu, M.S.^ 2 , Wei Gao, M.S.^ 3 , Yasheng Chen, D.Sc.^ 1 , Cheng was utilized to depict brain regions exhibiting temporal synchronization, also known as resting brain pixel-by-pixel throughout the entire brain, identifying regions with high temporal correlation. Results

Utah, University of

407

SKA SA test telescope reveals binary star system South Africa's test telescope reveals secrets of a binary star system and proves the country is able to  

E-Print Network [OSTI]

SKA SA test telescope reveals binary star system South Africa's test telescope reveals secrets, has created huge research and job opportunities. South Africa's Karoo Array Telescope (KAT-7) has at the SKA South Africa. The 64-dish MeerKAT ­ which SKA South Africa director Bernie Fanaroff once described

Jarrett, Thomas H.

408

Discovery of Pulsations from the Pulsar J0205 6449 in SNR 3C 58 with the Fermi Gamma-Ray Space Telescope  

SciTech Connect (OSTI)

We report the discovery of {gamma}-ray pulsations ({ge}0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the {gamma}-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold {gamma}-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 {+-} 0.01 {+-} 0.01 cycles which are aligned with the X-ray peaks. The first {gamma}-ray peak trails the radio pulse by 0.08 {+-} 0.01 {+-} 0.01, while its amplitude decreases with increasing energy as for the other {gamma}-ray pulsars. Spectral analysis of the pulsed {gamma}-ray emission suggests a simple power law of index -2.1 {+-} 0.1 {+-} 0.2 with an exponential cutoff at 3.0{sub -0.7}{sup +1.1} {+-} 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral {gamma}-ray photon flux above 0.1 GeV is (13.7 {+-} 1.4 {+-} 3.0) x 10{sup -8} cm{sup -2} s{sup -1}, which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 x 10{sup 34} erg s{sup -1} and an efficiency {eta} of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 x 10{sup -8} cm{sup -2} s{sup -1} for off-pulse emission from the object.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, Marco; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, William B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, Ronaldo; /INFN, Pisa; Berenji, Bijan; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, Roger D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, Anders W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bouvier, A.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /NASA, Goddard /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Manchester U. /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2011-12-01T23:59:59.000Z

409

SUZAKU X-RAY IMAGING OF THE EXTENDED LOBE IN THE GIANT RADIO GALAXY NGC 6251 ASSOCIATED WITH THE FERMI-LAT SOURCE 2FGL J1629.4+8236  

SciTech Connect (OSTI)

We report the results of a Suzaku X-ray imaging study of NGC 6251, a nearby giant radio galaxy with intermediate FR I/II radio properties. Our pointing direction was centered on the {gamma}-ray emission peak recently discovered with the Fermi Large Area Telescope (LAT) around the position of the northwest (NW) radio lobe 15 arcmin offset from the nucleus. After subtracting two 'off-source' pointings adjacent to the radio lobe and removing possible contaminants in the X-ray Imaging Spectrometer field of view, we found significant residual X-ray emission most likely diffuse in nature. The spectrum of the excess X-ray emission is well fitted by a power law with a photon index {Gamma} = 1.90 {+-} 0.15 and a 0.5-8 keV flux of 4 Multiplication-Sign 10{sup -13} erg cm{sup -2} s{sup -1}. We interpret this diffuse X-ray emission component as being due to inverse Compton upscattering of the cosmic microwave background photons by ultrarelativistic electrons within the lobe, with only a minor contribution from the beamed emission of the large-scale jet. Utilizing archival radio data for the source, we demonstrate by means of broadband spectral modeling that the {gamma}-ray flux of the Fermi-LAT source 2FGL J1629.4+8236 may well be accounted for by the high-energy tail of the inverse Compton continuum of the lobe. Thus, this claimed association of {gamma}-rays from the NW lobe of NGC 6251, together with the recent Fermi-LAT imaging of the extended lobes of Centaurus A, indicates that particles may be efficiently (re-)accelerated up to ultrarelativistic energies within extended radio lobes of nearby radio galaxies in general.

Takeuchi, Y.; Kataoka, J.; Takahashi, Y.; Maeda, K.; Nakamori, T. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Stawarz, L.; Tanaka, Y.; Takahashi, T. [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5510 (Japan); Cheung, C. C. [National Academy of Sciences, Washington, DC 20001 (United States); Celotti, A., E-mail: uto_of_take@suou.waseda.jp [Scuola Internazionale Superiore di Studi Avanzati (SISSA), 34014 Trieste (Italy)

2012-04-10T23:59:59.000Z

410

A comparison of Monte Carlo and Fermi-Eyges-Hogstrom estimates of heart and lung dose from breast electron boost treatment  

SciTech Connect (OSTI)

Purpose: Electrons are commonly used in the treatment of breast cancer primarily to deliver a tumor bed boost. We compared the use of the Monte Carlo (MC) method and the Fermi-Eyges-Hogstrom (FEH) algorithm to calculate the dose distribution of electron treatment to normal tissues. Methods and materials: Ten patients with left-sided breast cancer treated with breast-conservation therapy at the University of California, San Francisco, were included in this study. Each patient received an electron boost to the surgical bed to a dose of 1,600 cGy in 200 cGy fractions prescribed to 80% of the maximum. Doses to the left ventricle (LV) and the ipsilateral lung (IL) were calculated using the EGS4 MC system and the FEH algorithm implemented on the commercially available Pinnacle treatment planning system. An anthromorphic phantom was irradiated with radiochromic film in place to verify the accuracy of the MC system. Results: Dose distributions calculated with the MC algorithm agreed with the film measurements within 3% or 3 mm. For all patients in the study, the dose to the LV and IL was relatively low as calculated by MC. That is, the maximum dose received by up to 98% of the LV volume was < 100 cGy/day. Less than half of the IL received a dose in excess of 30 cGy/day. When compared with MC, FEH tended to show reduced penetration of the electron beam in lung, and FEH tended to overestimate the bremsstrahlung dose in regions well beyond the electron practical range. These differences were clinically likely to be of little significance, comprising differences of less than one-tenth of the LV and IL volume at doses > 30 cGy and differences in maximum dose of < 35 cGy/day to the LV and 80 cGy/day to the IL. Conclusions: From our series, using clinical judgment to prescribe the boost to the surgical bed after breast-conserving treatment results in low doses to the underlying LV and IL. When calculated dose distributions are desired, MC is the most accurate, but FEH can still be used.

Coleman, Joy [Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA (United States); Park, Catherine [Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA (United States); Villarreal-Barajas, J. Eduardo [Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA (United States); Petti, Paula [Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA (United States); Faddegon, Bruce [Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA (United States)]. E-mail: faddegon@radonc17.ucsf.edu

2005-02-01T23:59:59.000Z

411

Fermi LAT Detection of Pulsed Gamma-Rays From the Vela-Like Pulsars PSR J1048-5832 and PSR J2229+6114  

SciTech Connect (OSTI)

We report the detection of {gamma}-ray pulsations ({ge}0.1 GeV) from PSR J2229+6114 and PSR J1048-5832, the latter having been detected as a low-significance pulsar by EGRET. Data in the {gamma}-ray band were acquired by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemerides used to fold the {gamma}-ray light curves were obtained using the Green Bank Telescope, the Lovell telescope at Jodrell Bank, and the Parkes Telescope. The two young radio pulsars, located within the error circles of the previously unidentified EGRET sources 3EG J1048-5840 and 3EG J2227+6122, present spin-down characteristics similar to the Vela pulsar. PSR J1048-5832 shows two sharp peaks at phases 0.15 {+-} 0.01 and 0.57 {+-} 0.01 relative to the radio pulse confirming the EGRET light curve, while PSR J2229+6114 presents a very broad peak at phase 0.49 {+-} 0.01. The {gamma}-ray spectra above 0.1 GeV of both pulsars are fit with power laws having exponential cutoffs near 3 GeV, leading to integral photon fluxes of (2.19 {+-} 0.22 {+-} 0.32) x 10{sup -7} cm{sup -2} s{sup -1} for PSR J1048-5832 and (3.77 {+-} 0.22 {+-} 0.44) x 10{sup -7} cm{sup -2} s{sup -1} for PSR J2229+6114. The first uncertainty is statistical and the second is systematic. PSR J1048-5832 is one of the two LAT sources which were entangled together as 3EG J1048-5840. These detections add to the growing number of young {gamma}-ray pulsars that make up the dominant population of GeV {gamma}-ray sources in the Galactic plane.

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Baring, M.G.; /Rice U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Stockholm U. /Stockholm U., OKC /INFN, Trieste /Bari U. /INFN, Bari /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /INFN, Trieste /Arecibo Observ. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Bari U. /INFN, Bari /INFN, Bari /NASA, Goddard /Maryland U. /INFN, Perugia /Perugia U.; /more authors..

2012-03-29T23:59:59.000Z

412

X-RAY AND RADIO FOLLOW-UP OBSERVATIONS OF HIGH-REDSHIFT BLAZAR CANDIDATES IN THE FERMI-LAT UNASSOCIATED SOURCE POPULATION  

SciTech Connect (OSTI)

We report on the results of X-ray and radio follow-up observations of two GeV gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as candidates for high-redshift blazars from unassociated sources in the Fermi Large Area Telescope Second Source Catalog. We utilize the Suzaku satellite and the VLBI Exploration of Radio Astrometry (VERA) telescopes for X-ray and radio observations, respectively. For 2FGL J0923.5+1508, a possible radio counterpart NVSS J092357+150518 is found at 1.4 GHz from an existing catalog, but we do not detect any X-ray emission from it and derive a flux upper limit F{sub 2-8{sub keV}} < 1.37 Multiplication-Sign 10{sup -14} erg cm{sup -2} s{sup -1}. Radio observations at 6.7 GHz also result in an upper limit of S{sub 6.7{sub GHz}} < 19 mJy, implying a steep radio spectrum that is not expected for a blazar. On the other hand, we detect X-rays from NVSS J150229+555204, the potential 1.4 GHz radio counterpart of 2FGL J1502.1+5548. The X-ray spectrum can be fitted with an absorbed power-law model with a photon index {gamma} = 1.8{sup +0.3}{sub -0.2} and the unabsorbed flux is F{sub 2-8{sub keV}} = 4.3{sup +1.1}{sub -1.0} Multiplication-Sign 10{sup -14} erg cm{sup -2} s{sup -1}. Moreover, we detect unresolved radio emission at 6.7 GHz with flux S{sub 6.7{sub GHz}} = 30.1 mJy, indicating a compact, flat-spectrum radio source. If NVSS J150229+555204 is indeed associated with 2FGL J1502.1+5548, then we find that its multiwavelength spectrum is consistent with a blazar at redshift z {approx} 3-4.

Takahashi, Y.; Kataoka, J.; Nakamori, T.; Maeda, K. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 Japan (Japan); Niinuma, K. [Department of Physics, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi 753-8512 (Japan); Honma, M. [Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Inoue, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Totani, T. [Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Inoue, S., E-mail: s072803523@akane.waseda.jp [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2013-08-10T23:59:59.000Z

413

An Iridate with Fermi Arcs  

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

degeneracy. A minimal model based on these assumptions can reproduce much of the phenomenology of HTSC cuprates. Although it would be informative to study these key features in...

414

Interstellar Travel & The Fermi Paradox  

E-Print Network [OSTI]

to work on, but warp drive and worm holes may have to wait. #12;Interstellar Travel: Issues 1. How far do

Shirley, Yancy

415

Fermi Feud | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGYWomentheATLANTA, GA5 &ofDepartment ofThe development of efficient,

416

FermiCulture Subscription Form  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:Epitaxial ThinFORFALL NEWSFemtosecond X-ray4, ScientistsThe

417

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn Inside Look atAn

418

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn Inside Look atAnAn

419

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn Inside Look atAnAnAn

420

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn Inside Look atAnAnAnAn

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421

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn Inside Look

422

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mail ShareRed Cross BloodU.S.informationAnSpectroscopy.An

423

An Iridate with Fermi Arcs  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mail ShareRed Cross

424

E-Print Network 3.0 - archaeology reveals secrets Sample Search...  

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

Slavery and Material Culture Patricia Samford Summary: Plantation in James City County. The site, unearthed in 1970 during an archaeological survey, revealed... The...

425

E-Print Network 3.0 - atomic substitution reveals Sample Search...  

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

of Technology Collection: Chemistry 2 Point Defect Configurations of Supersaturated Au Atoms Inside Si Summary: microscopy (STEM) is used to reveal individual Au atom...

426

E-Print Network 3.0 - arabinofuranosidase reveals xylan-binding...  

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

51 Sequence and annotation of the 288-kb ATCV-1 virus that infects an endosymbiotic chlorella strain of the heliozoon Acanthocystis turfacea Summary: genomes have revealed more...

427

E-Print Network 3.0 - antarctica reveals non-organic Sample Search...  

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

for: antarctica reveals non-organic Page: << < 1 2 3 4 5 > >> 1 ANTARCTICA: BAROMETER OF CLIMATE CHANGE Report to the National Science Foundation from the Antarctic Meteorology...

428

Angels and Demons: The Science Revealed - or Tom Hanks and the...  

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

and Demons: The Science Revealed or Tom Hanks and the Unreasonable Effectiveness of Mathematics M. Bellis Department of Physics Stanford University May 25, 2009 M. Bellis Spring...

429

E-Print Network 3.0 - analysis reveal distinct Sample Search...  

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

are revealed; suggestions... of Balkan idioms (past and present) were analyzed in terms of Jakobsonian distinctive features. Various... quantitatively has been devised. The...

430

E-Print Network 3.0 - analysis reveals distinct Sample Search...  

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

are revealed; suggestions... of Balkan idioms (past and present) were analyzed in terms of Jakobsonian distinctive features. Various... quantitatively has been devised. The...

431

E-Print Network 3.0 - atomic structure reveals Sample Search...  

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

structure, thus revealing very subtle... Nonlinear Spectroscopy of Cold, Trapped Atoms: Atomic Recoil and Localization Effects in a MOT T... .if.uj.edu.plplZOAgrupywg.htm...

432

E-Print Network 3.0 - analysis reveals global Sample Search Results  

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

Physics 20 On the Trail of Polar Lows Scientists from the GKSS Research Centre in Geesthacht have developed a mathematical Summary: years revealed no direct correlation between...

433

E-Print Network 3.0 - alloys reveal fundamental Sample Search...  

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

1,dkembre 1991 Summary: -partioles form in alloyed zone. Laser alloying with TiB2 powder revealed less vaporization of powder than... Physical-TechnicalInstituteofthe...

434

Next Generation Lunch: Revealing the World’s First 3D Printed Car (text version)  

Broader source: Energy.gov [DOE]

Below is the text version for the Next Generation Lunch: Revealing the World’s First 3D Printed Car Video.

435

E-Print Network 3.0 - association scan reveals Sample Search...  

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

changed?" The remainder... into clusters, which are then grouped by target destination ports. This final comparison reveals scanning... are then grouped by target destination...

436

Plasma Proteome Response to Severe Burn Injury Revealed by 18O...  

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

Plasma Proteome Response to Severe Burn Injury Revealed by 18O-Labeled Universal” Reference-based Quantitative Proteomics. Plasma Proteome Response to Severe Burn Injury...

437

Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations  

E-Print Network [OSTI]

We report the results of a multi-band observing campaign on the famous blazer 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The $\\gamma$-ray emission of the source measured by Fermi-LAT showed multiple distinct flares reaching the highest flux level measured in this object since the beginning of the Fermi mission, with $F(E > 100\\,{\\rm MeV})$ of $10^{-5}$ photons cm$^{-2}$ s$^{-1}$, and with a flux doubling time scale as short as 2 hours. The $\\gamma$-ray spectrum during one of the flares was very hard, with an index of $\\Gamma_\\gamma = 1.7 \\pm 0.1$, which is rarely seen in flat spectrum radio quasars. The lack of concurrent optical variability implies a very high Compton dominance parameter $L_\\gamma/L_{\\rm syn} > 300$. Two 1-day NuSTAR observations with accompanying Swift pointings were separated by 2 weeks, probing different levels of source activity. While the 0.5$-$70 keV X-ray spectrum obtained during the first poi...

Hayashida, M; Madejski, G M; Sikora, M; Itoh, R; Ajello, M; Blandford, R D; Buson, S; Chiang, J; Fukazawa, Y; Furniss, A K; Urry, C M; Hasan, I; Harrison, F A; Alexander, D M; Balokovi?, M; Barret, D; Boggs, S E; Christensen, F E; Craig, W W; Forster, K; Giommi, P; Grefenstette, B; Hailey, C; Hornstrup, A; Kitaguchi, T; Koglin, J E; Madsen, K K; Mao, P H; Miyasaka, H; Mori, K; Perri, M; Pivovaroff, M J; Puccetti, S; Rana, V; Stern, D; Tagliaferri, G; Westergaard, N J; Zhang, W W; Zoglauer, A; Gurwell, M A; Uemura, M; Akitaya, H; Kawabata, K S; Kawaguch, K; Kanda, Y; Moritani, Y; Takaki, K; Ui, T; Yoshida, M; Agarwal, A; Gupta, A C

2015-01-01T23:59:59.000Z

438

Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets  

E-Print Network [OSTI]

Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets David Jon by raindrop impacts. We use high-speed imaging of drop impacts on dry sand to describe the drop (2007), Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets, J

439

Interspecies Avian Brain Chimeras Reveal That Large Brain Size Differences Are Influenced by Cell  

E-Print Network [OSTI]

Interspecies Avian Brain Chimeras Reveal That Large Brain Size Differences Are Influenced by Cell), and harvested the chimeras at later embryonic stages (between 9­12 days of incubation). The donor and host-C, Balaban E, Jarvis ED (2012) Interspecies Avian Brain Chimeras Reveal That Large Brain Size Differences

Jarvis, Erich D.

440

Fractal branching organizations of Ediacaran rangeomorph fronds reveal a lost Proterozoic body plan  

E-Print Network [OSTI]

Fractal branching organizations of Ediacaran rangeomorph fronds reveal a lost Proterozoic body plan, using parametric Lindenmayer systems, a first formal model of rangeomorph morphologies reveals a fractal-filling strategies. The fractal body plan of rangeomorphs is shown to maximize surface area, consistent

Cambridge, University of

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441

An XMM-Newton Observation of NGC 1399 Reveals Two Phases of Hot Gas and Super-Solar Abundances in the Central Regions  

E-Print Network [OSTI]

We present an initial analysis of a new XMM observation of NGC 1399, the central elliptical galaxy of the Fornax group. Spectral fitting of the spatially resolved spectral data of the EPIC MOS and pn CCDs reveals that a two-temperature model (2T) of the hot gas is favored over single-phase and cooling flow models within the central ~20 kpc. The preference for the 2T model applies whether or not the data are deprojected. The cooler component has a temperature (~0.9 keV) similar to the kinetic temperature of the stars while the hotter component has a temperature (~1.5 keV) characteristic of the virial temperature of a ~10^{13} M_sun halo. The two-phase model (and other multitemperature models) removes the ``Fe Bias'' within r < ~20 kpc and gives Z_Fe/Z_sun 1.5-2. At larger radii the iron abundance decreases until Z_Fe/Z_sun \\~0.5 for r ~50 kpc. The Si abundance is super-solar (1.2-1.7 solar) within the central regions while Z_Si/Z_Fe ~0.8 over the entire region studied. These Fe and Si abundances imply that ~80% of the Fe mass within r ~50 kpc originates from Type Ia supernovae (SNIa). This SNIa fraction is similar to that inferred for the Sun and therefore suggests a stellar initial mass function similar to the Milky Way.

David A. Buote

2002-06-24T23:59:59.000Z

442

Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico  

E-Print Network [OSTI]

Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico-carried from isolated mountaintops 75­100 km away. Because strontium from local dust, water, and underlying

443

Single-Cell Genomics Reveals Hundreds of Coexisting Subpopulations in Wild Prochlorococcus  

E-Print Network [OSTI]

Extensive genomic diversity within coexisting members of a microbial species has been revealed through selected cultured isolates and metagenomic assemblies. Yet, the cell-by-cell genomic composition of wild uncultured ...

Kashtan, Nadav

444

The genetic architecture of Down syndrome phenotypes revealed by high-resolution analysis  

E-Print Network [OSTI]

The genetic architecture of Down syndrome phenotypes revealed by high-resolution analysis of human, CA, and approved May 29, 2009 (received for review December 30, 2008) Down syndrome (DS), or trisomy

Gerstein, Mark

445

E-Print Network 3.0 - analyses reveals tradeoffs Sample Search...  

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

those who have similar... Trade-offs in Low-Income Women's Mate Preferences Within-Sex Differences in Reproductive Strategy... .g., income). A clus- ter analysis revealed two...

446

E-Print Network 3.0 - acetylation microarray reveals Sample Search...  

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

for: acetylation microarray reveals Page: << < 1 2 3 4 5 > >> 1 MOLECULAR AND CELLULAR BIOLOGY, Jan. 2004, p. 757764 Vol. 24, No. 2 0270-73060408.00 0 DOI: 10.1128...

447

E-Print Network 3.0 - aqueous environment revealed Sample Search...  

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

|J. Phys. Chem. Lett. 2011, 2, 25152520 Summary: )2SO4, and Na2CO3 Relative to CaCl2 and NaCl at the AirAqueous Interface Revealed by Heterodyne... the aqueous surface,...

448

E-Print Network 3.0 - adaptive optics reveal Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: adaptive optics reveal Page: << < 1 2 3 4 5 > >> 1 Two mechanisms for optic flow and scale change...

449

Revealing natural processes to the contemporary observer : Wal-Mart & stormwater runoff management  

E-Print Network [OSTI]

The natural landscape is a depository of natural processes at work--water flows and erodes earth; winds blow and deposit sands. The earth's surface reveals former and current environmental forces, many of which take millennia ...

Steger, Daniel Gerard, 1968-

2002-01-01T23:59:59.000Z

450

E-Print Network 3.0 - assembly domain reveals Sample Search Results  

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

state of the multiblock copolymer melt and to reveal... of several aspects of the self-assembly in block-copolymer-based systems. The self-assembly in two specific......

451

Self-similar multiscale structure of lignin revealed by neutron scattering and molecular dynamics simulation  

SciTech Connect (OSTI)

Lignin, a major polymeric component of plant cell walls, forms aggregates in vivo and poses a barrier to cellulosic ethanol production. Here, neutron scattering experiments and molecular dynamics simulations reveal that lignin aggregates are characterized by a surface fractal dimension that is invariant under change of scale from ~1 1000 . The simulations also reveal extensive water penetration of the aggregates and heterogeneous chain dynamics corresponding to a rigid core with a fluid surface.

Petridis, Loukas [ORNL; Pingali, Sai Venkatesh [ORNL; Urban, Volker S [ORNL; Heller, William T [ORNL; O'Neill, Hugh Michael [ORNL; Foston, Marcus [Georgia Institute of Technology; Ragauskas, A J [Georgia Institute of Technology; Smith, Jeremy C [ORNL

2011-01-01T23:59:59.000Z

452

Environmental genomics reveals a single species ecosystem deep within the Earth  

SciTech Connect (OSTI)

DNA from low biodiversity fracture water collected at 2.8 km depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium, Candidatus Desulforudis audaxviator, comprises>99.9percent of the microorganisms inhabiting the fluid phase of this particular fracture. Its genome indicates a motile, sporulating, sulfate reducing, chemoautotrophic thermophile that can fix its own nitrogen and carbon using machinery shared with archaea. Candidatus Desulforudis audaxviator is capable of an independent lifestyle well suited to long-term isolation from the photosphere deep within Earth?s crust, and offers the first example of a natural ecosystem that appears to have its biological component entirely encoded within a single genome.

Chivian, Dylan; Brodie, Eoin L.; Alm, Eric J.; Culley, David E.; Dehal, Paramvir S.; DeSantis, Todd Z.; Gihring, Thomas M.; Lapidus, Alla; Lin, Li-Hung; Lowry, Stephen R.; Moser, Duane P.; Richardson, Paul; Southam, Gordon; Wanger, Greg; Pratt, Lisa M.; Andersen, Gary L.; Hazen, Terry C.; Brockman, Fred J.; Arkin, Adam P.; Onstott, Tullis C.

2008-09-17T2