WorldWideScience

Sample records for frontier astrophysical instruments

  1. Exploring the cosmic frontier. Astrophysical instruments for the 21st century

    International Nuclear Information System (INIS)

    Lobanov, A.P.; Zensus, J.A.; Cesarsky, C.; Diamond, P.

    2007-01-01

    In the coming decades, astrophysical science will benefit enormously from the construction and operation of several major international ground- and space based facilities, such as ALMA, Herschel/Planck, and SKA in the far infrared to radio band, Extremely Large Telescopes, JWST and GAIA in the optical to near infrared regime, XEUS and Constellation-X in the X-ray, and GLAST in the Gamma-ray regime. These and other new instruments will have a major impact in a wide range of scientific topics including the cosmological epoch of reionization, galactic dynamics and nuclear activity, stellar astronomy, extra-solar planets, gamma-ray bursts, X-ray binaries, and many others. On May 18-21, 2004, the Max-Planck-Society's Harnack-Haus in Dahlem, Berlin hosted the international symposium ''Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century''. The symposium in Berlin was dedicated to exploring the complementarity and synergies between different branches of astrophysical research, by presenting and discussing the fundamental scientific problems that will be addressed by major future astrophysical facilities in the next few decades. This book contains 70 papers from the meeting and is intended to give a lasting account of a snapshot of an evolving scientific discourse and interaction throughout our field of research. (orig.)

  2. Exploring the Cosmic Frontier Astrophysical Instruments for the 21st Century

    CERN Document Server

    Lobanov, Andrei P; Cesarsky, Catherine; Diamond, Phillip J

    2007-01-01

    In the coming decades, astrophysical science will benefit enormously from the construction and operation of several major international ground- and space based facilities, such as ALMA, Herschel/Planck, and SKA in the far infrared to radio band, Extremely Large Telescopes, JWST and GAIA in the optical to near infrared regime, XEUS and Constellation-X in the X-ray, and GLAST in the Gamma-ray regime. These and other new instruments will have a major impact in a wide range of scientific topics including the cosmological epoch of reionization, galactic dynamics and nuclear activity, stellar astronomy, extra-solar planets, gamma-ray bursts, X-ray binaries, and many others. On May 18-21, 2004, the Max-Planck-Society’s Harnack-Haus in Dahlem, Berlin hosted the international symposium "Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century". The symposium in Berlin was dedicated to exploring the complementarity and synergies between different branches of astrophysical research, by presenting ...

  3. Frontier Research in Astrophysics - II

    Science.gov (United States)

    2016-05-01

    The purpose of this international workshop is to bring together astrophysicists and physicists who are involved in various topics at the forefront of modern astrophysics and particle physics. The workshop will discuss the most recent experimental and theoretical results in order to advance our understanding of the physics governing our Universe. To accomplish the goals of the workshop, we believe it is necessary to use data from ground-based and space-based experiments and results from theoretical developments: work on the forefront of science which has resulted (or promises to result in) high-impact scientific papers. Hence, the main purpose of the workshop is to discuss in a unique and collaborative setting a broad range of topics in modern astrophysics, from the Big Bang to Planets and Exoplanets. We believe that this can provide a suitable framework for each participant who (while obviously not involved in all the topics discussed), will be able to acquire a general view of the main experimental and theoretical results currently obtained. Such an up-to-date view of the current research on cosmic sources can help guide future research projects by the participants, and will encourage collaborative efforts across various topical areas of research. The proceedings will be published in Proceedings of Science (PoS)- SISSA and will provide a powerful resource for all the scientific community and will be especially helpful for PhD students. The following items will be reviewed: Cosmology: Cosmic Background, Dark Matter, Dark Energy, Clusters of Galaxies. Physics of the Diffuse Cosmic Sources. Physics of Cosmic Rays. Physics of Discrete Cosmic Sources. Extragalactic Sources: Active Galaxies, Normal Galaxies, Gamma-Ray Bursts. Galactic Sources: Star Formation, Pre-Main-Sequence and Main- Sequence Stars, the Sun, Cataclysmic Variables and Novae, Supernovae and SNRs, X-Ray Binary Systems, Pulsars, Black Holes, Gamma-Ray Sources, Nucleosynthesis, Asteroseismology

  4. Essays on the frontiers of modern astrophysics and cosmology

    CERN Document Server

    Mathew, Santhosh

    2014-01-01

    This book is a collection of engaging and intriguing essays that describe an intellectual journey from the beginning to the end of universe. It is the product of an ongoing effort to know our place in the universe and share with readers the underpinnings of the magnificent cosmos where we are given a chance to exist only very briefly. The essays incorporate a group of challenging ideas that modern physics and cosmology are struggling to understand, in a unique way that incorporates mythological, religious, and philosophical perspectives. The author relies on a simple and powerful philosophy that we are part of the universe and the universe is part of us.   This wonderful collection of essays provides a journey through the current frontiers of modern astrophysics and cosmology. Its depiction of the most important unsolved mysteries about our place in the Universe is peppered with original insights and philosophical perspectives, making it an intellectual treat. – Avi Loeb, Professor, Harvard University Chai...

  5. Advances in instrumentation for nuclear astrophysics

    Directory of Open Access Journals (Sweden)

    S. D. Pain

    2014-04-01

    Full Text Available The study of the nuclear physics properties which govern energy generation and nucleosynthesis in the astrophysical phenomena we observe in the universe is crucial to understanding how these objects behave and how the chemical history of the universe evolved to its present state. The low cross sections and short nuclear lifetimes involved in many of these reactions make their experimental determination challenging, requiring developments in beams and instrumentation. A selection of developments in nuclear astrophysics instrumentation is discussed, using as examples projects involving the nuclear astrophysics group at Oak Ridge National Laboratory. These developments will be key to the instrumentation necessary to fully exploit nuclear astrophysics opportunities at the Facility for Rare Isotope Beams which is currently under construction.

  6. Astronomy from the Moon: A New Frontier for 21st Century Astrophysics

    Science.gov (United States)

    Durst, Steve

    2018-06-01

    The International Lunar Observatory Association of Hawai'i USA continues into its second decade with research and development of South Pole instruments for astronomy, observation and communication from the Moon. Since the pioneering first astronomy observations from the Moon by Apollo 16 Commander John Young (an ILOA founding-emeritus director until his recent passing), with China Lunar Ultraviolet Telescope LUT operations and current American and European considerations for far-side radio telescopes, today's climate is most promising for a diversity of lunar-based astronomy locations, instruments and technologies. ILOA is aiming to advance this frontier through its Galaxy First Light Imaging program, being developed through contracts with Moon Express and Canadensys Aerospace Corp.A wide variety of extreme and unique lunar conditions enable many astronomy activities and installations, on the Moon's near-side, far-side, north pole, and south pole: The extremely thin lunar exosphere favors observations in millimeter / submillimeter to optical, UV, X-ray, and gamma-ray wavelengths; the highly stable platform that is the Moon provides for long-duration observations; ultra cold, shaded areas for cryogenic infrared instruments; far-side radio-quiet environment for radio telescopes and VLF astronomy; 1/6-Earth gravity for production and utilization of new, very lightweight materials and instruments, including large refractors, 100-m class liquid mirror telescopes, and possibly 1,000-m class radio telescopes and interferometer antenna arrays vastly larger than Atacama LMA; North and especially South Pole sites, with high peaks and long solar power windows, offer perhaps the widest variety of lunar conditions and opportunities for astronomical innovation on the Moon: a veritable "condominium of observatories".21st century astrophysics seems likely to find Luna a very busy and productive new frontier, as American Astronomical Society and IAU members will validate, with

  7. At the frontier of astrophysics and philosophy | Public conference by Hubert Reeves | 16 July

    CERN Multimedia

    2014-01-01

    "At the frontier of astrophysics and philosophy: between infinitely large and infinitely small" Public conference by Hubert Reeves Globe of Science and Innovation Wednesday 16 July 2014 - 7.00 p.m. Please note that this conference will be in French only. "The Universe is changing.  We are not strangers in the Universe: recent discoveries in astrophysics prove our intimate bond with everything shining in the sky." Save the date! On Wednesday 16 July 2014, Hubert Reeves, astrophysicist, philosopher and engaging communicator, is back at the Globe of Science and Innovation to talk about the frontiers of physics, astronomy and philosophy, two years after the discovery of the Higgs boson at CERN. If you ever wondered how this discovery has changed our knowledge of the Universe and strengthened the bond between the infinitely large world of astrophysics and the infinitely small world of quantum physics, this event is for you. The conference is part of POPSCIENCE, a p...

  8. Snowmass Computing Frontier: Computing for the Cosmic Frontier, Astrophysics, and Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, A. [Univ. of Washington, Seattle, WA (United States); Habib, S. [Argonne National Lab. (ANL), Lemont, IL (United States); Szalay, A. [Johns Hopkins Univ., Baltimore, MD (United States); Borrill, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fuller, G. [Univ. of California, San Diego, CA (United States); Gnedin, N. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Heitmann, K. [Argonne National Lab. (ANL), Lemont, IL (United States); Jacobs, D. [Arizona State Univ., Tempe, AZ (United States); Lamb, D. [Univ. of Chicago, IL (United States); Mezzacappa, T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Messer, B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Myers, S. [National Radio Astronomy Observatory, Socorro, NM (United States); Nord, B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Nugent, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); O' Shea, B. [Michigan State Univ., East Lansing, MI (United States); Ricker, P. [Univ. of Illinois, Urbana-Champaign, IL (United States); Schneider, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-12

    This document presents (off-line) computing requrements and challenges for Cosmic Frontier science, covering the areas of data management, analysis, and simulations. We invite contributions to extend the range of covered topics and to enhance the current descriptions.

  9. Continent-Spanning Radio Telescope Blazes Trails At the Frontiers of Astrophysics

    Science.gov (United States)

    1999-06-01

    The supersharp radio "vision" of the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) is revealing unprecedented details of astronomical objects from stars in our own cosmic neighborhood to galaxies billions of light-years away. Astronomers from across North America and beyond are presenting the results of VLBA research at the American Astronomical Society's (AAS) meeting in Chicago. "The VLBA is one of the most powerful tools in the world for astronomy," said Paul Vanden Bout, Director of the National Radio Astronomy Observatory (NRAO), which operates the VLBA. "It can produce images hundreds of times more detailed than those produced by the Hubble Space Telescope, and that capability has yielded some spectacular scientific results." Examples of VLBA research presented at the AAS meeting include the most accurate measurement ever made of the distance to another galaxy; the detection of our Solar System's orbital motion around the center of our own Galaxy; a "movie" showing the expansion of debris from a star's explosion in a galaxy 11 million light-years away; and a "movie" of gas motions in the atmosphere of a star more than 1,000 light-years away -- the first time gas motions have ever been tracked in a star other than the Sun. With ten giant dish antennas spread from Hawaii in the Pacific to St. Croix in the Caribbean, all working together as a single telescope, the VLBA is "the world's biggest astronomical instrument," Vanden Bout said. The VLBA has been in full operation for more than five years. A pair of sessions at the AAS meeting is devoted to reports of research using the VLBA. In more than 40 scientific presentations, astronomers tell how they used the VLBA to gain valuable new information about nearly every area from the frontiers of astrophysics. Some of those reporting on their VLBA research are graduate students working on their Ph.D degrees. "We are particularly proud that this instrument, one of the world's premier facilities

  10. Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 8: Instrumentation Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Demarteau, M; Lipton, R; Nicholson, H; Shipsey, I; Akerib, D; Albayrak-Yetkin, A; Alexander, J; Anderson, J; Artuso, M; Asner, D; Ball, R; Battaglia, M; Bebek, C; Beene, J; Benhammou, Y; Bentefour, E; Bergevin, M; Bernstein, A; Bilki, B; Blucher, E; Bolla, G; Bortoletto, D; Bowden, N; Brooijmans, G; Byrum, K; Cabrera, B; Cancelo, G; Carlstrom, J; Casey, B; Chang, C; Chapman, J; Chen, CH; Childres, I; Christian, D; Convery, M; Corso, WCJ; Cumalat, J; Cushman, P; Via, CD; Dazeley, S; Debbins, P; Deptuch, G; Dhawan, S; Benedetto, VD; DiGiovene, B; Djurcic, Z; Dye, S; Elagin, A; Estrada, J; Evans, H; Etzion, E; Fast, J; Ferretti, C; Fisher, P; Fleming, B; Francis, K; Friedman, P; Frisch, H; Garcia-Sciveres, M; Gatto, C; Geronim, G; Gilchriese, G; Golwala, S; Grant, C; Grillo, A; Grünendahl, E; Gorham, P; Guan, L; Gutierrez, G; Haber, C; Hall, J; Haller, G; Hast, C; Heintz, U; Hemmick, T; Hitlin, DG; Hogan, C; Hohlmann, M; Hoppe, E; Hsu, L; Huffer, M; Irwin, K; Izraelevitch, F; Jennings, G; Johnson, M; Jung, A; Kagan, H; Kenney, C; Kettell, S; Khanna, R; Khristenko, V; Krennrich, F; Kuehn, K; Kutschke, R; Learned, J; Lee, AT; Levin, D; Liu, T; Liu, ATK; Lissauer, D; Love, J; Lynn, D; MacFarlane, D; Magill, S; Majewski, S; Mans, J; Maricic, J; Marleau, P; Mazzacane, A; McKinsey, D; Mehl, J; Mestvirisvilli, A; Meyer, S; Mokhov, N; Moshe, M; Mukherjee, A; Murat, P; Nahn, S; Narain, M; Nadel-Turonski, P; Newcomer, M; Nishimura, K; Nygren, D; Oberla, E; Onel, Y; Oreglia, M; Orrell, J; Paley, J; Para, A; Parker, S; Polychronakos, V; Pordes, S; Privitera, P; Prosser, A; Pyle, M; Raaf, J; Ramberg, E; Rameika, R; Rebel, B; Repond, J; Reyna, D; Ristori, L; Rivera, R; Ronzhin, A; Rusack, R; Russ, J; Ryd, A; Sadrozinski, H; Sahoo, H; Sanchez, MC; Sanzeni, C; Schnetzer, S; Seidel, S; Seiden, A; Schmidt, I; Shenai, A; Shutt, T; Silver, Y; Smith, W; Snowden-Ifft, D; Sonnenschein, A; Southwick, D; Spiegel, L; Stanitzki, M; Striganov, S; Su, D; Sumner, R; Svoboda, R; Sweany, M; Talaga, R; Tayloe, R; Tentindo, S; Terentiev, N; Thom-Levy, J; Thorn, C; Tiffenberg, J; Trischuk, W; Tschirhart, R; Turner, M; Underwood, D; Uplegger, L; Urheim, J; Vagins, M; Bibber, KV; Varner, G; Varner, R; Va' vra, J; Lippe, HVD; Wagner, R; Wagner, S; Weaverdyck, C; Wenzel, H; Weinstein, A; Wetstein, M; White, A; Wigman, R; Wilson, P; Winn, D; Winter, P; Woody, C; Xia, L; Xie, JQ; Ye, Z; Yeh, MF; Yetkin, T; Yoo, JH; Yu, J; Yu, JM; Zeller, S; Zhang, JL; Zhu, JJ; Zhou, B; Zhu, RY; Zitzer, B

    2014-01-23

    These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 8, on the Instrumentation Frontier, discusses the instrumentation needs of future experiments in the Energy, Intensity, and Cosmic Frontiers, promising new technologies for particle physics research, and issues of gathering resources for long-term research in this area.

  11. Compendium of Instrumentation Whitepapers on Frontier Physics Needs for Snowmass 2013

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-01-01

    Contents of collection of whitepapers include: Operation of Collider Experiments at High Luminosity; Level 1 Track Triggers at HL-LHC; Tracking and Vertex Detectors for a Muon Collider; Triggers for hadron colliders at the energy frontier; ATLAS Upgrade Instrumentation; Instrumentation for the Energy Frontier; Particle Flow Calorimetry for CMS; Noble Liquid Calorimeters; Hadronic dual-readout calorimetry for high energy colliders; Another Detector for the International Linear Collider; e+e- Linear Colliders Detector Requirements and Limitations; Electromagnetic Calorimetry in Project X Experiments The Project X Physics Study; Intensity Frontier Instrumentation; Project X Physics Study Calorimetry Report; Project X Physics Study Tracking Report; The LHCb Upgrade; Neutrino Detectors Working Group Summary; Advanced Water Cherenkov R&D for WATCHMAN; Liquid Argon Time Projection Chamber (LArTPC); Liquid Scintillator Instrumentation for Physics Frontiers; A readout architecture for 100,000 pixel Microwave Kinetic In- ductance Detector array; Instrumentation for New Measurements of the Cosmic Microwave Background polarization; Future Atmospheric and Water Cherenkov ?-ray Detectors; Dark Energy; Can Columnar Recombination Provide Directional Sensitivity in WIMP Search?; Instrumentation Needs for Detection of Ultra-high Energy Neu- trinos; Low Background Materials for Direct Detection of Dark Matter; Physics Motivation for WIMP Dark Matter Directional Detection; Solid Xenon R&D at Fermilab; Ultra High Energy Neutrinos; Instrumentation Frontier: Direct Detection of WIMPs; nEXO detector R&D; Large Arrays of Air Cherenkov Detectors; and Applications of Laser Interferometry in Fundamental Physics Experiments.

  12. NASA Astrophysics Education and Public Outreach: Engaging Educators and Students in Exploring the Cosmic Frontier

    Science.gov (United States)

    Lawton, Brandon L.; Eisenhamer, Bonnie; Smith, Denise Anne; Jirdeh, Hussein; Summers, Frank; Darnell, John T.; Ryer, Holly

    2015-08-01

    NASA’s Frontier Fields is an ambitious three-year Great Observatories program that will expand our understanding of galaxy formation and evolution in the early universe. The program includes six deep-field observations of strong-lensing galaxy clusters that will be taken in parallel with six deep “blank fields.” The observations allow astronomers to look deeper into the universe than ever before, and potentially uncover galaxies that are as much as 100 times fainter than what the telescopes can typically observe. The Frontier Fields science program is ideal for informing audiences about scientific advances and topics in STEM. The study of galaxy properties, statistics, optics, and Einstein’s theory of general relativity naturally leverages off of the science returns of the Frontier Fields program. As a result, the Space Telescope Science Institute’s Office of Public Outreach (OPO) has initiated an E/PO project to follow the progress of the Frontier Fields.For over two decades, the Hubble E/PO program has sought to bring the wonders of the universe to the education community, the youth, and the public, and engage audiences in the adventure of scientific discovery. Program components include standards-based curriculum-support materials, exhibits and exhibit components, professional development workshops, and direct interactions with scientists. We are also leveraging our new social media strategy to bring the science program to the public in the form of an ongoing blog. The main underpinnings of the program’s infrastructure are scientist-educator development teams, partnerships, and an embedded program evaluation component. OPO is leveraging this existing infrastructure to bring the Frontier Fields science program to the education community and the public in a cost-effective way.This talk features the goals and current status of the Frontier Fields E/PO program, with a particular emphasis on our education goals and achievements. We also highlight OPO

  13. Extending the frontiers of mass spectrometric instrumentation and methods

    Energy Technology Data Exchange (ETDEWEB)

    Schieffer, Gregg Martin [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    The focus of this dissertation is two-fold: developing novel analysis methods using mass spectrometry and the implementation and characterization of a novel ion mobility mass spectrometry instrumentation. The novel mass spectrometry combines ion trap for ion/ion reactions coupled to an ion mobility cell. The long term goal of this instrumentation is to use ion/ion reactions to probe the structure of gas phase biomolecule ions. The three ion source - ion trap - ion mobility - qTOF mass spectrometer (IT - IM - TOF MS) instrument is described. The analysis of the degradation products in coal (Chapter 2) and the imaging plant metabolites (Appendix III) fall under the methods development category. These projects use existing commercial instrumentation (JEOL AccuTOF MS and Thermo Finnigan LCQ IT, respectively) for the mass analysis of the degraded coal products and the plant metabolites, respectively. The coal degradation paper discusses the use of the DART ion source for fast and easy sample analysis. The sample preparation consisted of a simple 50 fold dilution of the soluble coal products in water and placing the liquid in front of the heated gas stream. This is the first time the DART ion source has been used for analysis of coal. Steven Raders under the guidance of John Verkade came up with the coal degradation projects. Raders performed the coal degradation reactions, worked up the products, and sent them to me. Gregg Schieffer developed the method and wrote the paper demonstrating the use of the DART ion source for the fast and easy sample analysis. The plant metabolite imaging project extends the use of colloidal graphite as a sample coating for atmospheric pressure LDI. DC Perdian and I closely worked together to make this project work. Perdian focused on building the LDI setup whereas Schieffer focused on the MSn analysis of the metabolites. Both Perdian and I took the data featured in the paper. Perdian was the primary writer of the paper and used it as a

  14. Prototyping a Global Soft X-Ray Imaging Instrument for Heliophysics, Planetary Science, and Astrophysics Science

    Science.gov (United States)

    Collier, M. R.; Porter, F. S.; Sibeck, D. G.; Carter, J. A.; Chiao, M. P.; Chornay, D. J.; Cravens, T.; Galeazzi, M.; Keller, J. W.; Koutroumpa, D.; hide

    2012-01-01

    We describe current progress in the development of a prototype wide field-of-view soft X-ray imager that employs Lobstereye optics and targets heliophysics, planetary, and astrophysics science. The prototype will provide proof-of-concept for a future flight instrument capable of imaging the entire dayside magnetosheath from outside the magnetosphere. Such an instrument was proposed for the ESA AXIOM mission.

  15. Prototyping a Global Soft X-ray Imaging Instrument for Heliophysics, Planetary Science, and Astrophysics Science

    Science.gov (United States)

    Collier, Michael R.; Porter, F. Scott; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chornay, Dennis J.; Cravens, Thomas; Galeazzi, Massimiliano; Keller, John W.; Koutroumpa, Dimitra; hide

    2012-01-01

    We describe current progress in the development of a prototype wide field-of-view soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The prototype will provide proof-of-concept for a future flight instrument capable of imaging the entire dayside magnetosheath from outside the magnetosphere. Such an instrument was proposed for the FSA AXIOM mission

  16. Final Report for DoE Grant DE-SC-0011689 - Studies of Particle Astrophysics at the Cosmic Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Nitz, David F. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Physics; Fick, Brian E. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Physics

    2016-05-13

    Our research focuses on the “Cosmic Frontier”, one of the three principle thrusts of the DoE Office of Science High Energy Physics research program. The 2013 community summer study “Snowmass on the Mississippi” catalyzed joint work to describe the status and future prospects of this research thrust. Over its history, the field of cosmic ray studies has provided many discoveries of central importance to the the progress of high energy physics, including the identification of new elementary particles, measurements of particle interactions far above accelerator energies, and the confirmation of neutrino oscillations. In our research we continued this tradition, employing 2 instruments (the Auger Observatory and the HAWC Observatory) to study high energy physics questions using cosmic rays. One approach to addressing particle physics questions at the cosmic frontier is to study the very highest energy cosmic rays. This has been the major thrust of our research effort. The two largest currently operating ultra-high energy cosmic ray (UHECR) observatories are the Pierre Auger Observatory in the Southern hemisphere, covering an area of 3000 km2 and the Telescope Array (TA) in the Northern hemisphere, covering about 700 km2. The observatories sample the cosmic ray air showers at ground level (with 1660 water Cerenkov stations in the Auger surface detector), and also measure the longitudinal development of air showers on clear moonless nights (approx. 10% of the events) using atmospheric fluorescence detectors. The observatories have recently installed low energy extensions, which provide an overlap with the LHC energy regime. The Auger and TA teams have established joint working groups to discuss experimental methods, compare data analyses and modeling, and perform cross calibrations. Another approach is to study high energy gamma rays. The High Altitude Water Cerenkov (HAWC) gamma-ray observatory is located at 4100 m above sea level near Pico

  17. The fundamentals of modern astrophysics a survey of the cosmos from the home planet to space frontiers

    CERN Document Server

    Marov, Mikhail Ya

    2015-01-01

    The Fundamentals of Modern Astrophysics provides an overview of the modern science of astrophysics. It covers the Sun, Solar System bodies, exoplanets, stars, and star life cycle, planetary systems origin and evolution, basics of astrobiology, our galaxy the Milky Way, other galaxies and galactic clusters, a general view of the Universe, its structure, evolution and fate, modern views and advanced models of cosmology as well as the synergy of micro- and macro physics, standard model, superstring theory, multiversity and worm holes. The main concepts of modern astrophysics and prospects for future studies are accompanied by numerous illustrations and a summary of the advanced projects at various astronomical facilities and space missions. Dr. Marov guides readers through a maze of complicated topics to demystify the field and open its wonders to all.

  18. Astrophysics today

    International Nuclear Information System (INIS)

    Cameron, A.G.W.

    1984-01-01

    Examining recent history, current trends, and future possibilities, the author reports the frontiers of research on the solar system, stars, galactic physics, and cosmological physics. The book discusses the great discoveries in astronomy and astrophysics and examines the circumstances in which they occurred. It discusses the physics of white dwarfs, the inflationary universe, the extinction of dinosaurs, black hole, cosmological models, and much more

  19. The SLICE, CHESS, and SISTINE Ultraviolet Spectrographs: Rocket-Borne Instrumentation Supporting Future Astrophysics Missions

    Science.gov (United States)

    France, Kevin; Hoadley, Keri; Fleming, Brian T.; Kane, Robert; Nell, Nicholas; Beasley, Matthew; Green, James C.

    2016-03-01

    NASA’s suborbital program provides an opportunity to conduct unique science experiments above Earth’s atmosphere and is a pipeline for the technology and personnel essential to future space astrophysics, heliophysics, and atmospheric science missions. In this paper, we describe three astronomy payloads developed (or in development) by the Ultraviolet Rocket Group at the University of Colorado. These far-ultraviolet (UV) (100-160nm) spectrographic instruments are used to study a range of scientific topics, from gas in the interstellar medium (accessing diagnostics of material spanning five orders of magnitude in temperature in a single observation) to the energetic radiation environment of nearby exoplanetary systems. The three instruments, Suborbital Local Interstellar Cloud Experiment (SLICE), Colorado High-resolution Echelle Stellar Spectrograph (CHESS), and Suborbital Imaging Spectrograph for Transition region Irradiance from Nearby Exoplanet host stars (SISTINE) form a progression of instrument designs and component-level technology maturation. SLICE is a pathfinder instrument for the development of new data handling, storage, and telemetry techniques. CHESS and SISTINE are testbeds for technology and instrument design enabling high-resolution (R>105) point source spectroscopy and high throughput imaging spectroscopy, respectively, in support of future Explorer, Probe, and Flagship-class missions. The CHESS and SISTINE payloads support the development and flight testing of large-format photon-counting detectors and advanced optical coatings: NASA’s top two technology priorities for enabling a future flagship observatory (e.g. the LUVOIR Surveyor concept) that offers factors of ˜50-100 gain in UV spectroscopy capability over the Hubble Space Telescope. We present the design, component level laboratory characterization, and flight results for these instruments.

  20. Laboratory Astrophysics Prize: Laboratory Astrophysics with Nuclei

    Science.gov (United States)

    Wiescher, Michael

    2018-06-01

    Nuclear astrophysics is concerned with nuclear reaction and decay processes from the Big Bang to the present star generation controlling the chemical evolution of our universe. Such nuclear reactions maintain stellar life, determine stellar evolution, and finally drive stellar explosion in the circle of stellar life. Laboratory nuclear astrophysics seeks to simulate and understand the underlying processes using a broad portfolio of nuclear instrumentation, from reactor to accelerator from stable to radioactive beams to map the broad spectrum of nucleosynthesis processes. This talk focuses on only two aspects of the broad field, the need of deep underground accelerator facilities in cosmic ray free environments in order to understand the nucleosynthesis in stars, and the need for high intensity radioactive beam facilities to recreate the conditions found in stellar explosions. Both concepts represent the two main frontiers of the field, which are being pursued in the US with the CASPAR accelerator at the Sanford Underground Research Facility in South Dakota and the FRIB facility at Michigan State University.

  1. Frontier Analysis

    DEFF Research Database (Denmark)

    Assaf, A. George; Josiassen, Alexander

    2016-01-01

    This article presents a comprehensive review of frontier studies in the tourism literature. We discuss the main advantages and disadvantages of the various frontier approaches, in particular, the nonparametric and parametric frontier approaches. The study further differentiates between micro...

  2. Particle Physics & Astrophysics (PPA)

    Data.gov (United States)

    Federal Laboratory Consortium — Scientists at SLAC's Particle Physics and Astrophysics develop and utilize unique instruments from underground to outer space to explore the ultimate laws of nature...

  3. An invitation to astrophysics

    CERN Document Server

    Padmanabhan, Thanu

    2006-01-01

    This unique book provides a clear and lucid description of several aspects of astrophysics and cosmology in a language understandable to a physicist or beginner in astrophysics. It presents the key topics in all branches of astrophysics and cosmology in a simple and concise language. The emphasis is on currently active research areas and exciting new frontiers rather than on more pedantic topics. Many complicated results are introduced with simple, novel derivations which strengthen the conceptual understanding of the subject. The book also contains over one hundred exercises which will help s

  4. 1997 report of the scientific evaluation committee of DAPNIA (Department of astrophysics, particle physics, nuclear physics and instrumentation)

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The DAPNIA is a department of CEA, its main characteristic is to manage scientific teams working on astrophysics, nuclear physics, elementary particles and instrumentation. Every 2 years DAPNIA's activities are submitted to an evaluation made by a scientific committee whose members are experts independent from CEA. This committee reviews the work done, gives an opinion about the options chosen for the projects to come and writes out a report. In 1997 the committee had a very positive opinion of the work done by DAPNIA teams. The contributions to various and important national or international programs have been successful, we can quote: Ulysse mission, soho, iso, integral for spatial programs, aleph, delphi, H1 at Hera, atlas, cms, na48, nomad, babar, antares for particle physics and spiral, smc, compass for nuclear physics. The committee advises DAPNIA to favour more contacts between the theoreticians and the experimentalists who work on quantum chromodynamics and hadron physics. The committee shows its concern about improving the balance between the means dedicated to instrumentation designing and those dedicated to the analysis and interpretation of the experimental data collected. (A.C.)

  5. Observational astrophysics

    CERN Document Server

    Smith, Robert C

    1995-01-01

    Combining a critical account of observational methods (telescopes and instrumentation) with a lucid description of the Universe, including stars, galaxies and cosmology, Smith provides a comprehensive introduction to the whole of modern astrophysics beyond the solar system. The first half describes the techniques used by astronomers to observe the Universe: optical telescopes and instruments are discussed in detail, but observations at all wavelengths are covered, from radio to gamma-rays. After a short interlude describing the appearance of the sky at all wavelengths, the role of positional astronomy is highlighted. In the second half, a clear description is given of the contents of the Universe, including accounts of stellar evolution and cosmological models. Fully illustrated throughout, with exercises given in each chapter, this textbook provides a thorough introduction to astrophysics for all physics undergraduates, and a valuable background for physics graduates turning to research in astronomy.

  6. Frontier constellations

    DEFF Research Database (Denmark)

    Eilenberg, Michael

    2014-01-01

    expansion, population resettlement and securitization, and the confluence of these dynamic processes creates special frontier constellations. Through the case of the Indonesian-Malaysian borderlands, I explore how processes of frontier colonization through agricultural expansion have been a recurrent...

  7. Frontier spaces

    DEFF Research Database (Denmark)

    Rasmussen, Mattias Borg; Lund, Christian

    2018-01-01

    The global expansion of markets produces frontiers of contestation over the definition and control of resources. In a frontier context, new patterns of resource exploration, extraction, and commodification create new territories. A recently published collection (Rasmussen and Lund 2018) explores...

  8. Impossible Frontiers

    OpenAIRE

    Brennan, Thomas J.; Lo, Andrew W.

    2009-01-01

    A key result of the Capital Asset Pricing Model (CAPM) is that the market portfolio---the portfolio of all assets in which each asset's weight is proportional to its total market capitalization---lies on the mean-variance efficient frontier, the set of portfolios having mean-variance characteristics that cannot be improved upon. Therefore, the CAPM cannot be consistent with efficient frontiers for which every frontier portfolio has at least one negative weight or short position. We call such ...

  9. [Exploring Flow and Supervision of Medical Instruments by Standing on Frontier of the Reform of Free Trade Zone].

    Science.gov (United States)

    Shen, Jianhua; Han, Meixian; Lu, Fei

    2017-11-30

    Shanghai Waigaoqiao Free Trade Zone as one of the special customs supervision areas of China (Shanghai) free trade pilot area, gathered a large number of general agent enterprises related to medical apparatus and instruments. This article analyzes the characteristics of special environment and medical equipment business in Shanghai Waigaoqiao Free Trade Zone in order to further implement the national administrative examination and approval reform. According to the latest requirement in laws and regulations of medical instruments, and trend of development in the industry of medical instruments, as well as research on the basis of practices of market supervision in countries around the world, this article also proposes measures about precision supervision, coordination of supervision, classification supervision and dynamic supervision to establish a new order of fair and standardized competition in market, and create conditions for establishment of allocation and transport hub of international medicine.

  10. Gravitational Wave Astrophysics: Opening the New Frontier

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    A new era in astronomy will begin when the gravitational wave window onto the universe opens in approx. 5 years, as ground-based detectors make the first detections in the high-frequency regime. Since the universe is nearly transparent to gravitational waves, these signals carry direct information about their sources - such as masses, spins, luminosity distances, and orbital parameters - through dense, obscured regions across cosmic time. This talk will explore gravitational waves as cosmic messengers, highlighting key sources and opportunities for multi-messenger astronomy across the gravitational wave spectrum.

  11. Relativistic Astrophysics

    International Nuclear Information System (INIS)

    Font, J. A.

    2015-01-01

    The relativistic astrophysics is the field of astrophysics employing the theory of relativity Einstein as physical-mathematical model is to study the universe. This discipline analyzes astronomical contexts in which the laws of classical mechanics of Newton's law of gravitation are not valid. (Author)

  12. Essential astrophysics

    CERN Document Server

    Lang, Kenneth R

    2013-01-01

    Essential Astrophysics is a book to learn or teach from, as well as a fundamental reference volume for anyone interested in astronomy and astrophysics. It presents astrophysics from basic principles without requiring any previous study of astronomy or astrophysics. It serves as a comprehensive introductory text, which takes the student through the field of astrophysics in lecture-sized chapters of basic physical principles applied to the cosmos. This one-semester overview will be enjoyed by undergraduate students with an interest in the physical sciences, such as astronomy, chemistry, engineering or physics, as well as by any curious student interested in learning about our celestial science. The mathematics required for understanding the text is on the level of simple algebra, for that is all that is needed to describe the fundamental principles. The text is of sufficient breadth and depth to prepare the interested student for more advanced specialized courses in the future. Astronomical examples are provide...

  13. Frontier commodification

    DEFF Research Database (Denmark)

    Bennike, Rune Bolding

    2017-01-01

    In the contemporary global imagination, Darjeeling typically figures on two accounts: as a unique tourism site replete with colonial heritage and picturesque nature, and as the productive origin for some of the world's most exclusive teas. In this commodified and consumable form, Darjeeling is part...... of material and representational interventions, I uncover the particular assemblage of government and capital that enabled this transformation and highlight its potential resonances with contemporary cases of frontier commodification in South Asia and beyond....

  14. The NASA Astrophysics Program

    Science.gov (United States)

    Zebulum, Ricardo S.

    2011-01-01

    NASA's scientists are enjoying unprecedented access to astronomy data from space, both from missions launched and operated only by NASA, as well as missions led by other space agencies to which NASA contributed instruments or technology. This paper describes the NASA astrophysics program for the next decade, including NASA's response to the ASTRO2010 Decadal Survey.

  15. Astrophysical Flows

    Science.gov (United States)

    Pringle, James E.; King, Andrew

    2003-07-01

    Almost all conventional matter in the Universe is fluid, and fluid dynamics plays a crucial role in astrophysics. This new graduate textbook provides a basic understanding of the fluid dynamical processes relevant to astrophysics. The mathematics used to describe these processes is simplified to bring out the underlying physics. The authors cover many topics, including wave propagation, shocks, spherical flows, stellar oscillations, the instabilities caused by effects such as magnetic fields, thermal driving, gravity, shear flows, and the basic concepts of compressible fluid dynamics and magnetohydrodynamics. The authors are Directors of the UK Astrophysical Fluids Facility (UKAFF) at the University of Leicester, and editors of the Cambridge Astrophysics Series. This book has been developed from a course in astrophysical fluid dynamics taught at the University of Cambridge. It is suitable for graduate students in astrophysics, physics and applied mathematics, and requires only a basic familiarity with fluid dynamics.• Provides coverage of the fundamental fluid dynamical processes an astrophysical theorist needs to know • Introduces new mathematical theory and techniques in a straightforward manner • Includes end-of-chapter problems to illustrate the course and introduce additional ideas

  16. Nuclear astrophysics

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1992-01-01

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized

  17. Relativistic astrophysics

    CERN Document Server

    Demianski, Marek

    2013-01-01

    Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity

  18. Nuclear astrophysics

    International Nuclear Information System (INIS)

    Lehoucq, Roland; Klotz, Gregory

    2015-11-01

    Astronomy deals with the position and observation of the objects in our Universe, from planets to galaxies. It is the oldest of the sciences. Astrophysics is the study of the physical properties of these objects. It dates from the start of the 20. century. Nuclear astrophysics is the marriage of nuclear physics, a laboratory science concerned with the infinitely small, and astrophysics, the science of what is far away and infinitely large. Its aim is to explain the origin, evolution and abundance of the elements in the Universe. It was born in 1938 with the work of Hans Bethe, an American physicist who won the Nobel Prize for physics in 1967, on the nuclear reactions that can occur at the center of stars. It explains where the incredible energy of the stars and the Sun comes from and enables us to understand how they are born, live and die. The matter all around us and from which we are made, is made up of ninety-two chemical elements that can be found in every corner of the Universe. Nuclear astrophysics explains the origin of these chemical elements by nucleosynthesis, which is the synthesis of atomic nuclei in different astrophysical environments such as stars. Nuclear astrophysics provides answers to fundamental questions: - Our Sun and the stars in general shine because nuclear reactions are taking place within them. - The stars follow a sequence of nuclear reaction cycles. Nucleosynthesis in the stars enables us to explain the origin and abundance of elements essential to life, such as carbon, oxygen, nitrogen and iron. - Star explosions, in the form of supernovae, disperse the nuclei formed by nucleosynthesis into space and explain the formation of the heaviest chemical elements such as gold, platinum and lead. Nuclear astrophysics is still a growing area of science. (authors)

  19. Cosmic physics: the high energy frontier

    International Nuclear Information System (INIS)

    Stecker, F W

    2003-01-01

    Cosmic rays have been observed up to energies 10 8 times larger than those of the best particle accelerators. Studies of astrophysical particles (hadrons, neutrinos and photons) at their highest observed energies have implications for fundamental physics as well as astrophysics. Thus, the cosmic high energy frontier is the nexus to new particle physics. This overview discusses recent advances being made in the physics and astrophysics of cosmic rays and cosmic γ-rays at the highest observed energies as well as the related physics and astrophysics of very high energy cosmic neutrinos. These topics touch on questions of grand unification, violations of Lorentz invariance as well as Planck scale physics and quantum gravity. (topical review)

  20. Astrophysical Concepts

    CERN Document Server

    Harwit, Martin

    2006-01-01

    This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events but does not portray them in detail: it provides a series of astrophysical sketches. For this fourth edition, nearly every part of the text has been reconsidered and rewritten, new sections have been added to cover recent developments, and others have been extensively revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and enumerates some of the outstanding problems faced in the field today. The basic physics needed to tackle these questions are developed in the next few chapters using specific astronomical processes as examples. The second half of the book enlarges on these topics and shows how we can obtain quantitative insight into the structure and evolution of...

  1. Nuclear astrophysics

    International Nuclear Information System (INIS)

    Arnould, M.; Takahashi, K.

    1999-01-01

    Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress made in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other subfields of physics and chemistry have also contributed to that advance. Notwithstanding the accomplishment, many long-standing problems remain to be solved, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endangering old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing, the astrophysicists and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, we pick here some specific nuclear

  2. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  3. Neutrino astrophysics

    International Nuclear Information System (INIS)

    Roulet, E.

    2001-01-01

    A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

  4. High Time Resolution Astrophysics

    CERN Document Server

    Phelan, Don; Shearer, Andrew

    2008-01-01

    High Time Resolution Astrophysics (HTRA) is an important new window to the universe and a vital tool in understanding a range of phenomena from diverse objects and radiative processes. This importance is demonstrated in this volume with the description of a number of topics in astrophysics, including quantum optics, cataclysmic variables, pulsars, X-ray binaries and stellar pulsations to name a few. Underlining this science foundation, technological developments in both instrumentation and detectors are described. These instruments and detectors combined cover a wide range of timescales and can measure fluxes, spectra and polarisation. These advances make it possible for HTRA to make a big contribution to our understanding of the Universe in the next decade.

  5. Relativistic astrophysics

    CERN Document Server

    Price, R H

    1993-01-01

    Work reported in the workshop on relativistic astrophysics spanned a wide varicy of topics. Two specific areas seemed of particular interest. Much attention was focussed on gravitational wave sources, especially on the waveforms they produce, and progress was reported in theoretical and observational aspects of accretion disks.

  6. Observational astrophysics

    CERN Document Server

    Léna, Pierre; Lebrun, François; Mignard, François; Pelat, Didier

    2012-01-01

    This is the updated, widely revised, restructured and expanded third edition of Léna et al.'s successful work Observational Astrophysics. It presents a synthesis on tools and methods of observational astrophysics of the early 21st century. Written specifically for astrophysicists and graduate students, this textbook focuses on fundamental and sometimes practical limitations on the ultimate performance that an astronomical system may reach, rather than presenting particular systems in detail. In little more than a decade there has been extraordinary progress in imaging and detection technologies, in the fields of adaptive optics, optical interferometry, in the sub-millimetre waveband, observation of neutrinos, discovery of exoplanets, to name but a few examples. The work deals with ground-based and space-based astronomy and their respective fields. And it also presents the ambitious concepts behind space missions aimed for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spec...

  7. astrophysical significance

    Directory of Open Access Journals (Sweden)

    Dartois E.

    2014-02-01

    Full Text Available Clathrate hydrates, ice inclusion compounds, are of major importance for the Earth’s permafrost regions and may control the stability of gases in many astrophysical bodies such as the planets, comets and possibly interstellar grains. Their physical behavior may provide a trapping mechanism to modify the absolute and relative composition of icy bodies that could be the source of late-time injection of gaseous species in planetary atmospheres or hot cores. In this study, we provide and discuss laboratory-recorded infrared signatures of clathrate hydrates in the near to mid-infrared and the implications for space-based astrophysical tele-detection in order to constrain their possible presence.

  8. Stellar astrophysics

    International Nuclear Information System (INIS)

    1987-01-01

    A number of studies in the field of steller astrophysics were undertaken by the South African Astronomical Observatory in 1986. These studies included; evolutionary effects on the surface abundances of an early-type supergiant; hydrogen deficient stars; t tauri stars; rotational modulation and flares on RS CVn and BY Dra stars; carbon and heavy element stars, and slow variability and circumstellar shells of red variable stars. 4 figs

  9. Reconfiguring frontier spaces

    DEFF Research Database (Denmark)

    Rasmussen, Mattias Borg; Lund, Christian

    2018-01-01

    The expansion of capitalism produces contests over the definition and control of resources. On a global scale, new patterns of resource exploration, extraction, and commodification create new territories. This takes place within a dynamic of frontiers and territorialization. Frontier dynamics...

  10. Astrophysical cosmology

    Science.gov (United States)

    Bardeen, J. M.

    The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper limits on the anisotropy of the microwave background radiation are gradually getting tighter and constraining more severely theoretical scenarios for the evolution of the universe.

  11. Astrophysical cosmology

    International Nuclear Information System (INIS)

    Bardeen, J.M.

    1986-01-01

    The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper limits on the anisotropy of the microwave background radiation are gradually getting tighter and constraining more severely theoretical scenarios for the evolution of the universe. 47 refs

  12. Instrumentation

    International Nuclear Information System (INIS)

    Prieur, G.; Nadi, M.; Hedjiedj, A.; Weber, S.

    1995-01-01

    This second chapter on instrumentation gives little general consideration on history and classification of instrumentation, and two specific states of the art. The first one concerns NMR (block diagram of instrumentation chain with details on the magnets, gradients, probes, reception unit). The first one concerns precision instrumentation (optical fiber gyro-meter and scanning electron microscope), and its data processing tools (programmability, VXI standard and its history). The chapter ends with future trends on smart sensors and Field Emission Displays. (D.L.). Refs., figs

  13. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2000-01-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised

  14. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  15. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2001-01-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor

  16. High energy astrophysical techniques

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents ultraviolet and X-ray astronomy, gamma-ray astronomy, cosmic ray astronomy, neutrino astronomy, and gravitational wave astronomy as distinct research areas, focusing on the astrophysics targets and the requirements with respect to instrumentation and observation methods. The purpose of the book is to bridge the gap between the reference books and the specialized literature. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities. The physical principles of photon and particle detectors are then addressed, and the specific telescopes and combinations of detectors, presented. Finally the instruments and their limits are discussed with a view to assisting readers in the planning and execution of observations. Astronomical observations with high-energy photons and particles represent the newest additions to multimessenger astronomy and this book will be of value to all with an interest in the field.

  17. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2002-01-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described

  18. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described.

  19. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised.

  20. Instrumentation

    International Nuclear Information System (INIS)

    Umminger, K.

    2008-01-01

    A proper measurement of the relevant single and two-phase flow parameters is the basis for the understanding of many complex thermal-hydraulic processes. Reliable instrumentation is therefore necessary for the interaction between analysis and experiment especially in the field of nuclear safety research where postulated accident scenarios have to be simulated in experimental facilities and predicted by complex computer code systems. The so-called conventional instrumentation for the measurement of e. g. pressures, temperatures, pressure differences and single phase flow velocities is still a solid basis for the investigation and interpretation of many phenomena and especially for the understanding of the overall system behavior. Measurement data from such instrumentation still serves in many cases as a database for thermal-hydraulic system codes. However some special instrumentation such as online concentration measurement for boric acid in the water phase or for non-condensibles in steam atmosphere as well as flow visualization techniques were further developed and successfully applied during the recent years. Concerning the modeling needs for advanced thermal-hydraulic codes, significant advances have been accomplished in the last few years in the local instrumentation technology for two-phase flow by the application of new sensor techniques, optical or beam methods and electronic technology. This paper will give insight into the current state of instrumentation technology for safety-related thermohydraulic experiments. Advantages and limitations of some measurement processes and systems will be indicated as well as trends and possibilities for further development. Aspects of instrumentation in operating reactors will also be mentioned.

  1. Instruments

    International Nuclear Information System (INIS)

    Buehrer, W.

    1996-01-01

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs

  2. Observational Cosmology with the Planck satellite: extraction of the astrophysical signal from raw data of HFI instrument and study of the impact of cosmic rays

    International Nuclear Information System (INIS)

    Girard, D.

    2010-01-01

    Cosmology is a very old science. It's goal is to describe the Universe at large scales. The standard model of cosmology is an inflation-CDM Big-Bang model. It is based on General Relativity. The cosmic microwave background is one of the three pillars of this model, with the expansion of the Universe and the primordial nucleosynthesis. It is the oldest detectable radiation in the Universe. The study of its temperature and polarisation anisotropies allow us to access direct information about the content and the geometry of the primordial Universe. The Planck satellite, launched on May 14 of 2009, represents the third generation of satellite missions which study the cosmic microwave background. The exceptional sensitivity of its instruments, High Frequency Instrument and Low Frequency Instrument, will allow us to constrain very strongly the cosmological models describing the early Universe, particularly the inflationary period, and to measure the cosmological parameters which describe the evolution of the Universe with an accuracy down to the percent. To reach these ambitious scientific objectives, each systematic instrumental effect has to be severely controlled and corrected by the data analysis. The effect of cosmic rays interacting with the bolometers of HFI, which is one of the most important effects, and which differs significatively from predictions, is corrected during the time ordered data analysis. The detailed understanding of this phenomenon and its modeling are necessary to correct it and to reach an optimal effective sensitivity. They will permit to take this effect into account in the conception of the future instruments detectors. This thesis proposes a first part focused on cosmology, a second part describing the Planck satellite, the HFI instrument and particularly its detectors and a third part dedicated to the HFI instrument data analysis. I concentrate on time ordered data analysis and on the corrections of instrumental systematic effects. Then I

  3. Instrumentation

    International Nuclear Information System (INIS)

    Muehllehner, G.; Colsher, J.G.

    1982-01-01

    This chapter reviews the parameters which are important to positron-imaging instruments. It summarizes the options which various groups have explored in designing tomographs and the methods which have been developed to overcome some of the limitations inherent in the technique as well as in present instruments. The chapter is not presented as a defense of positron imaging versus single-photon or other imaging modality, neither does it contain a description of various existing instruments, but rather stresses their common properties and problems. Design parameters which are considered are resolution, sampling requirements, sensitivity, methods of eliminating scattered radiation, random coincidences and attenuation. The implementation of these parameters is considered, with special reference to sampling, choice of detector material, detector ring diameter and shielding and variations in point spread function. Quantitation problems discussed are normalization, and attenuation and random corrections. Present developments mentioned are noise reduction through time-of-flight-assisted tomography and signal to noise improvements through high intrinsic resolution. Extensive bibliography. (U.K.)

  4. Astrophysics at very high energies

    International Nuclear Information System (INIS)

    Aharonian, Felix; Bergstroem, Lars; Dermer, Charles

    2013-01-01

    Presents three complementary lectures on very-high-energy astrophysics given by worldwide leaders in the field. Reviews the recent advances in and prospects of gamma-ray astrophysics and of multi-messenger astronomy. Prepares readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors. With the success of Cherenkov Astronomy and more recently with the launch of NASA's Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergstroem presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.

  5. Observational astrophysics.

    Science.gov (United States)

    Léna, P.; Lebrun, F.; Mignard, F.

    This book is the 2nd edition of an English translation published in 1988 (45.003.105) of the French original "Astrophysique: Méthodes physiques de l'observation" published in 1986 (42.003.048). Written specifically for physicists and graduate students in astronomy, this textbook focuses on astronomical observation and on the basic physical principles that astronomers use to conceive, build and exploit their instruments at their ultimate limits in sensitivity or resolution. This second edition has been entirely restructured and almost doubled in size, in order to improve its clarity and to account for the great progress achieved in the last 15 years. It deals with ground-based and space-based astronomy and their respective fields. It presents the new generation of giant ground-based telescopes, with the new methods of optical interferometry and adaptive optics, and also the ambitious concepts behind planned space missions for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spectrum and touches upon the "new astronomies" becoming possible with gravitational waves and neutrinos.

  6. Old/Past/Ancient/Historic Frontiers in Black Hole Astrophysics

    Science.gov (United States)

    Trimble, Virginia

    Basic questions about black holes, some of which are fairly old, include (1) What is a black hole? (2) Do black holes exist? And the answer to this depends a good deal on the answer to (1), (3) Where, when, why, and how have they formed? and (4) What are they good for? Here I attempt some elaboration of the questions and partial answers, noting that general relativity is required to described some of the phenomena, while dear old Isaac Newton is OK for others.

  7. The frontier beneath our feet

    Science.gov (United States)

    Grant, Gordon E.; Dietrich, William E.

    2017-04-01

    Following the simple question as to where water goes when it rains leads to one of the most exciting frontiers in earth science: the critical zone—Earth's dynamic skin. The critical zone extends from the top of the vegetation canopy through the soil and down to fresh bedrock and the bottom of the groundwater. Only recently recognized as a distinct zone, it is challenging to study because it is hard to observe directly, and varies widely across biogeoclimatic regions. Yet new ideas, instruments, and observations are revealing surprising and sometimes paradoxical insights, underscoring the value of field campaigns and long-term observatories. These insights bear directly on some of the most pressing societal problems today: maintaining healthy forests, sustaining streamflow during droughts, and restoring productive terrestrial and aquatic ecosystems. The critical zone is critical because it supports all terrestrial life; it is the nexus where water and carbon is cycled, vegetation (hence food) grows, soil develops, landscapes evolve, and we live. No other frontier is so close to home.

  8. The Frontiers of the Astronomical Universe

    Science.gov (United States)

    Pecker, Jean-Claude

    1977-01-01

    Reviews the current state of knowledge obtained by means of observations using the increasingly powerful or proficient instruments of astrophysics, radio astronomy, and space astronomy by satellite. In conclusion, he refers to certain mathematical entities introduced into the theory of the origins and evolution of the cosmos. (Author/MA)

  9. Frontiers in fusion research

    CERN Document Server

    Kikuchi, Mitsuru

    2011-01-01

    Frontiers in Fusion Research provides a systematic overview of the latest physical principles of fusion and plasma confinement. It is primarily devoted to the principle of magnetic plasma confinement, that has been systematized through 50 years of fusion research. Frontiers in Fusion Research begins with an introduction to the study of plasma, discussing the astronomical birth of hydrogen energy and the beginnings of human attempts to harness the Sun's energy for use on Earth. It moves on to chapters that cover a variety of topics such as: * charged particle motion, * plasma kinetic theory, *

  10. Superheated superconducting granules: a detector for particle physics and astrophysics

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.; Perret-Gallix, D.

    1987-01-01

    A general introduction to superheated superconducting granules (SSG) detectors is given and some recent results on their basic properties are presented. Granules recently made by industrial producers exhibit good metastability properties and show sensitivity, better than naively expected, to photons and ionizing particles. The behaviour of SSG detectors at very low temperatures is also discussed. We finally sketch a critical review of proposed applications to the cross-disciplinary frontier between particle physics and astrophysics

  11. Astrophysical Hydrodynamics An Introduction

    CERN Document Server

    Shore, Steven N

    2007-01-01

    This latest edition of the proven and comprehensive treatment on the topic -- from the bestselling author of ""Tapestry of Modern Astrophysics"" -- has been updated and revised to reflect the newest research results. Suitable for AS0000 and AS0200 courses, as well as advanced astrophysics and astronomy lectures, this is an indispensable theoretical backup for studies on celestial body formation and astrophysics. Includes exercises with solutions.

  12. Gravity, particles and astrophysics

    International Nuclear Information System (INIS)

    Wesson, P.S.

    1980-01-01

    The author deals with the relationship between gravitation and elementary particle physics, and the implications of these subjects for astrophysics. The text is split up into two parts. The first part represents a relatively non-technical overview of the subject, while the second part represents a technical examination of the most important aspects of non-Einsteinian gravitational theory and its relation to astrophysics. Relevant references from the fields of gravitation, elementary particle theory and astrophysics are included. (Auth.)

  13. The Climate Adaptation Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Benjamin L [ORNL

    2013-01-01

    Climate adaptation has emerged as a mainstream risk management strategy for assisting in maintaining socio-ecological systems within the boundaries of a safe operating space. Yet, there are limits to the ability of systems to adapt. Here, we introduce the concept of an adaptation frontier , which is defined as a socio-ecological system s transitional adaptive operating space between safe and unsafe domains. A number of driving forces are responsible for determining the sustainability of systems on the frontier. These include path dependence, adaptation/development deficits, values conflicts and discounting of future loss and damage. The cumulative implications of these driving forces are highly uncertain. Nevertheless, the fact that a broad range of systems already persist at the edge of their frontiers suggests a high likelihood that some limits will eventually be exceeded. The resulting system transformation is likely to manifest as anticipatory modification of management objectives or loss and damage. These outcomes vary significantly with respect to their ethical implications. Successful navigation of the adaptation frontier will necessitate new paradigms of risk governance to elicit knowledge that encourages reflexive reevaluation of societal values that enable or constrain sustainability.

  14. The Final Frontier

    DEFF Research Database (Denmark)

    Baron, Christian

    2017-01-01

    in living conditions, where neglect or reckless behavior may have fatal consequences. Exploring the consequences of such behavior in Tom Godwin’s short story ‘The Cold Equations’ (1954) as well as Ridley Scott’s film, Alien (1979), it argues that such ‘frontier situations’ warrant a change in the general...

  15. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. Anilkumar. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 30 Review Article. Large Area X-Ray Proportional Counter (LAXPC) Instrument on AstroSat and Some Preliminary Results from its Performance in the Orbit.

  16. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Jordan Vannitsen. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 4 December 2017 pp 70 Research Article. A Satellite Data Analysis and CubeSat Instrument Simulator Tool for Simultaneous Multi-spacecraft Measurements of Solar ...

  17. Rounding Up the Astrophysical Weeds

    Science.gov (United States)

    McMillan, James P.

    2016-09-01

    New instruments used for astronomy such as ALMA, Herschel, and SOFIA have greatly increased the quality of available astrophysical data. These improved data contain spectral lines and features which are not accounted for in the quantum mechanical (QM) catalogs. A class of molecules has been identified as being particularly problematic, the so-called "weeds". These molecules have numerous transitions, of non-trivial intensity, which are difficult to model due to highly perturbed low lying vibrational states. The inability to properly describe the complete contribution of these weeds to the astrophysical data has led directly to the misidentification of other target molecules. Ohio State's Microwave Laboratory has developed an alternative approach to this problem. Rather than relying on complex QM calculations, we have developed a temperature dependent approach to laboratory based terahertz spectroscopy. We have developed a set of simple packages, in addition to traditional line list catalogs, that enable astronomers to successfully remove the weed signals from their data. This dissertation will detail my laboratory work and analysis of three keys weeds: methanol, methyl formate and methyl cyanide. Also, discussed will be the analytical technique I used to apply these laboratory results to astrophysical data.

  18. Astrophysical Institute, Potsdam

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    Built upon a tradition of almost 300 years, the Astrophysical Institute Potsdam (AIP) is in an historical sense the successor of one of the oldest astronomical observatories in Germany. It is the first institute in the world which incorporated the term `astrophysical' in its name, and is connected with distinguished scientists such as Karl Schwarzschild and Albert Einstein. The AIP constitutes on...

  19. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  20. Plasma in astrophysics

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1982-10-01

    Two examples of plasma phenomena of importance to astrophysics are reviewed. These are examples where astrophysical understanding hinges on further progress in plasma physics understanding. The two examples are magnetic reconnection and the collisionless interaction between a population of energetic particles and a cooler gas or plasma, in particular the interaction between galactic cosmic rays and the interstellar medium

  1. Annual symposium on Frontiers in Science

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, N.; Fulton, K.R.

    1998-12-31

    This final report summarizes activities conducted for the National Academy of Sciences' Annual Symposium on Frontiers of Science with support from the US Department of Energy for the period July 1, 1993 through May 31, 1998. During the report period, five Frontiers of Science symposia were held at the Arnold and Mabel Beckman Center of the National Academies of Sciences and Engineering. For each Symposium, an organizing committee appointed by the NAS President selected and planned the eight sessions for the Symposium and identified general participants for invitation by the NAS President. These Symposia accomplished their goal of bringing together outstanding younger (age 45 or less) scientists to hear presentations in disciplines outside their own and to discuss exciting advances and opportunities in their fields in a format that encourages, and allows adequate time for, informal one-on-one discussions among participants. Of the 458 younger scientists who participated, over a quarter (124) were women. Participant lists for all symposia (1993--1997) are attached. The scientific participants were leaders in basic research from academic, industrial, and federal laboratories in such disciplines as astronomy, astrophysics, atmospheric science, biochemistry, cell biology, chemistry, computer science, earth sciences, engineering, genetics, material sciences, mathematics, microbiology, neuroscience, physics, and physiology. For each symposia, the 24 speakers and discussants on the program were urged to focus their presentations on current cutting-edge research in their field for a scientifically sophisticated but non-specialist audience, and to provide a sense of the experimental data--what is actually measured and seen in the various fields. They were also asked to address questions such as: What are the major research problems and unique tools in their field? What are the current limitations on advances as well as the frontiers? Speakers were asked to provide a

  2. Frontiers in Superconducting Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Superconducting Materials gives a state-of-the-art report of the most important topics of the current research in superconductive materials and related phenomena. It comprises 30 chapters written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students. It also addresses electronic and electrical engineers. Even non-specialists interested in superconductivity might find some useful answers.

  3. PARTICLE BEAMS: Frontier course

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe

  4. PARTICLE BEAMS: Frontier course

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-01-15

    Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe.

  5. About pioneer frontiers

    Directory of Open Access Journals (Sweden)

    Hervé Théry

    2014-09-01

    Full Text Available The geographer Pierre Monbeig wrote texts far ahead of his time, who deserve to be read today as they are useful in understanding today's pioneering frontiers. These are nowadays much further north than in his time, in the Amazon, contested between advocates of environmental protection and production of meat and grains, which has appeared on the southern ,lank of Brazilian Amazon, in Mato Grosso.

  6. Frontiers in Gold Chemistry

    OpenAIRE

    Ahmed A. Mohamed

    2015-01-01

    Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

  7. Prairie, gold and frontier

    International Nuclear Information System (INIS)

    Chirico, S.

    2005-01-01

    ThIs work deals with the mining history of the region of Cunapiru, Uruguay. Its process develops inside a rural world, and in this aspect it is not very different to other praires of similar geographic zones.Nevertheless, the fact of being a frontier territory makes it singular, different, and peculiar enough to transform this praire deeply. Memories of prosperity times nurture a centenarian illusion of manfified, inexact dating or significance facts. However, all that memories were essentials to collective identify.

  8. Astrophysics in a nutshell

    CERN Document Server

    Maoz, Dan

    2007-01-01

    A concise but thorough introduction to the observational data and theoretical concepts underlying modern astronomy, Astrophysics in a Nutshell is designed for advanced undergraduate science majors taking a one-semester course. This well-balanced and up-to-date textbook covers the essentials of modern astrophysics--from stars to cosmology--emphasizing the common, familiar physical principles that govern astronomical phenomena, and the interplay between theory and observation. In addition to traditional topics such as stellar remnants, galaxies, and the interstellar medium, Astrophysics in a N

  9. Astronomy and astrophysics for the 1970's. Volume 2. Reports of the panels

    International Nuclear Information System (INIS)

    1973-01-01

    Specific panel reports include: radio astronomy, optical astronomy, infrared astronomy, space astronomy, solar astronomy, theoretical astrophysics, dynamical astronomy, astrophysics and relativity, and statistics. These provide guidance as to the major trends anticipated in astronomical and astrophysical research. They also list instrumental facilities, auxiliary equipment, and programs of theoretical research and offer numerous recommendations

  10. Where is the Efficient Frontier

    OpenAIRE

    Jing Chen

    2010-01-01

    Tremendous effort has been spent on the construction of reliable efficient frontiers. However, mean-variance efficient portfolios constructed using sample means and covariance often perform poorly out of sample. We prove that, the capital market line is the efficient frontier for the risky assets in a financial market with liquid fixed income trading. This unified understanding of riskless asset as the boundary of risky assets relieves the burden of constructing efficient frontiers in asset a...

  11. High energy astrophysics

    International Nuclear Information System (INIS)

    Engel, A.R.

    1979-01-01

    High energy astrophysical research carried out at the Blackett Laboratory, Imperial College, London is reviewed. Work considered includes cosmic ray particle detection, x-ray astronomy, gamma-ray astronomy, gamma and x-ray bursts. (U.K.)

  12. 2004 ASTRONOMY & ASTROPHYSICS

    Indian Academy of Sciences (India)

    user

    This publication of the Academy on Astronomy and Astrophysics is unique in ... bring out position papers on societal issues where science plays a major ..... funding agencies, the Astronomical Society of ..... orbit very close to the parent star.

  13. Topics in Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Chung, K.C.

    1982-01-01

    Some topics in nuclear astrophysics are discussed, e.g.: highly evolved stellar cores, stellar evolution (through the temperature analysis of stellar surface), nucleosynthesis and finally the solar neutrino problem. (L.C.) [pt

  14. Astrophysics Decoding the cosmos

    CERN Document Server

    Irwin, Judith A

    2007-01-01

    Astrophysics: Decoding the Cosmos is an accessible introduction to the key principles and theories underlying astrophysics. This text takes a close look at the radiation and particles that we receive from astronomical objects, providing a thorough understanding of what this tells us, drawing the information together using examples to illustrate the process of astrophysics. Chapters dedicated to objects showing complex processes are written in an accessible manner and pull relevant background information together to put the subject firmly into context. The intention of the author is that the book will be a 'tool chest' for undergraduate astronomers wanting to know the how of astrophysics. Students will gain a thorough grasp of the key principles, ensuring that this often-difficult subject becomes more accessible.

  15. Particle Physics at the Cosmic, Intensity, and Energy Frontiers

    Energy Technology Data Exchange (ETDEWEB)

    Essig, Rouven

    2018-04-06

    Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Search (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.

  16. Collisionless plasmas in astrophysics

    CERN Document Server

    Belmont, Gerard; Mottez, Fabrice; Pantellini, Filippo; Pelletier, Guy

    2013-01-01

    Collisionless Plasmas in Astrophysics examines the unique properties of media without collisions in plasma physics. Experts in this field, the authors present the first book to concentrate on collisionless conditions in plasmas, whether close or not to thermal equilibrium. Filling a void in scientific literature, Collisionless Plasmas in Astrophysics explains the possibilities of modeling such plasmas, using a fluid or a kinetic framework. It also addresses common misconceptions that even professionals may possess, on phenomena such as "collisionless (Landau) damping". Abundant illustrations

  17. Nonlinear dynamics and astrophysics

    International Nuclear Information System (INIS)

    Vallejo, J. C.; Sanjuan, M. A. F.

    2000-01-01

    Concepts and techniques from Nonlinear Dynamics, also known as Chaos Theory, have been applied successfully to several astrophysical fields such as orbital motion, time series analysis or galactic dynamics, providing answers to old questions but also opening a few new ones. Some of these topics are described in this review article, showing the basis of Nonlinear Dynamics, and how it is applied in Astrophysics. (Author)

  18. Frontiers in Computer Education

    CERN Document Server

    Zhu, Egui; 2011 International Conference on Frontiers in Computer Education (ICFCE 2011)

    2012-01-01

    This book is the proceedings of the 2011 International Conference on Frontiers in Computer Education (ICFCE 2011) in Sanya, China, December 1-2, 2011. The contributions can be useful for researchers, software engineers, and programmers, all interested in promoting the computer and education development. Topics covered are computing and communication technology, network management, wireless networks, telecommunication, Signal and Image Processing, Machine Learning, educational management, educational psychology, educational system, education engineering, education technology and training.  The emphasis is on methods and calculi for computer science and education technology development, verification and verification tools support, experiences from doing developments, and the associated theoretical problems.

  19. Frontiers in nuclear chemistry

    International Nuclear Information System (INIS)

    Sood, D.D.; Reddy, A.V.R.; Pujari, P.K.

    1996-01-01

    This book contains articles on the landmarks in nuclear and radiochemistry which takes through scientific history spanning over five decades from the times of Roentgen to the middle of this century. Articles on nuclear fission and back end of the nuclear fuel cycle give an insight into the current status of this subject. Reviews on frontier areas like lanthanides, actinides, muonium chemistry, accelerator based nuclear chemistry, fast radiochemical separations and nuclear medicine bring out the multidisciplinary nature of nuclear sciences. This book also includes an article on environmental radiochemistry and safety. Chapters relevant to INIS are indexed separately

  20. Frontiers in Magnetic Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Magnetic Materials focuses on the current achievements and state-of-the-art advancements in magnetic materials. Several lines of development- High-Tc Superconductivity, Nanotechnology and refined experimental techniques among them – raised knowledge and interest in magnetic materials remarkably. The book comprises 24 chapters on the most relevant topics written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students.

  1. Introducing "Frontiers in Zoology"

    Science.gov (United States)

    Heinze, Jürgen; Tautz, Diethard

    2004-09-29

    As a biological discipline, zoology has one of the longest histories. Today it occasionally appears as though, due to the rapid expansion of life sciences, zoology has been replaced by more or less independent sub-disciplines amongst which exchange is often sparse. However, the recent advance of molecular methodology into "classical" fields of biology, and the development of theories that can explain phenomena on different levels of organisation, has led to a re-integration of zoological disciplines promoting a broader than usual approach to zoological questions. Zoology has re-emerged as an integrative discipline encompassing the most diverse aspects of animal life, from the level of the gene to the level of the ecosystem.The new journal Frontiers in Zoology is the first Open Access journal focussing on zoology as a whole. It aims to represent and re-unite the various disciplines that look at animal life from different perspectives and at providing the basis for a comprehensive understanding of zoological phenomena on all levels of analysis. Frontiers in Zoology provides a unique opportunity to publish high quality research and reviews on zoological issues that will be internationally accessible to any reader at no cost.

  2. Astronomical optical interferometry, II: Astrophysical results

    Directory of Open Access Journals (Sweden)

    Jankov S.

    2011-01-01

    Full Text Available Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution. Based on a great leap forward in the quality and quantity of interferometric data, the astrophysical applications are not limited anymore to classical subjects, such as determination of fundamental properties of stars; namely, their effective temperatures, radii, luminosities and masses, but the present rapid development in this field allowed to move to a situation where optical interferometry is a general tool in studies of many astrophysical phenomena. Particularly, the advent of long-baseline interferometers making use of very large pupils has opened the way to faint objects science and first results on extragalactic objects have made it a reality. The first decade of XXI century is also remarkable for aperture synthesis in the visual and near-infrared wavelength regimes, which provided image reconstructions from stellar surfaces to Active Galactic Nuclei. Here I review the numerous astrophysical results obtained up to date, except for binary and multiple stars milliarcsecond astrometry, which should be a subject of an independent detailed review, taking into account its importance and expected results at microarcsecond precision level. To the results obtained with currently available interferometers, I associate the adopted instrumental settings in order to provide a guide for potential users concerning the appropriate instruments which can be used to obtain the desired astrophysical information.

  3. Toward observational neutrino astrophysics

    International Nuclear Information System (INIS)

    Koshiba, M.

    1988-01-01

    It is true that: (1) The first observation of the neutrino burst from the supernova SN1987a by Kamiokande-II which was immediately confirmed by IBM; and (2) the first real-time, directional, and spectral observation of solar 8 B neutrinos also by Kamiokande-II could perhaps be considered as signalling the birth of observational astrophysics. The field, however, is still in its infancy and is crying out for tender loving care. Namely, while the construction of astronomy requires the time and the direction of the signal and that of astrophysics requires, in addition to the spectral information, the observations of (1) could not give the directional information and the results of both (1) and (2) are still suffering from the meager statistics. How do we remedy this situation to let this new born science of observational neutrino astrophysics grow healthy. This is what the author addresses in this talk. 15 refs., 8 figs

  4. Numerical simulation in astrophysics

    International Nuclear Information System (INIS)

    Miyama, Shoken

    1985-01-01

    There have been many numerical simulations of hydrodynamical problems in astrophysics, e.g. processes of star formation, supernova explosion and formation of neutron stars, and general relativistic collapse of star to form black hole. The codes are made to be suitable for computing such problems. In astrophysical hydrodynamical problems, there are the characteristics: problems of self-gravity or external gravity acting, objects of scales very large or very short, objects changing by short period or long time scale, problems of magnetic force and/or centrifugal force acting. In this paper, we present one of methods of numerical simulations which may satisfy these requirements, so-called smoothed particle methods. We then introduce the methods briefly. Then, we show one of the applications of the methods to astrophysical problem (fragmentation and collapse of rotating isothermal cloud). (Mori, K.)

  5. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Arnould, M.; Rayet, M.

    1990-01-01

    At all times and at all astrophysical scales, nuclear reactions have played and continue to play a key role. This concerns the energetics as well as the production of nuclides (nucleosynthesis). After a brief review of the observed composition of various objects in the universe, and especially of the solar system, the basic ingredients that are required in order to build up models for the chemical evolution of galaxies are sketched. Special attention is paid to the evaluation of the stellar yields through an overview of the important burning episodes and nucleosynthetic processes that can develop in non-exploding or exploding stars. Emphasis is put on the remaining astrophysical and nuclear physics uncertainties that hamper a clear understanding of the observed characteristics, and especially compositions, of a large variety of astrophysical objects

  6. The new astrophysics

    International Nuclear Information System (INIS)

    Longair, M.

    1989-01-01

    The author offers a review of advances in astrophysics since 1945 when astronomers started to explore the universe beyond the bounds of the optical wavelength of the electromagnetic spectrum, especially in the fields of radio, x ray and gamma ray, cosmic ray, ultraviolet and infrared astronomies, as well as neutral hydrogen and molecular line studies. Theoretical and technological advances have also kept pace. An overview of the new astrophysics is offered focusing on the large-scale distribution of matter and the background microwave radiation, galaxies, stellar evolution and the interstellar media (dust, gas and high energy particles). Nucleosynthesis in stars is mentioned in a broader discussion of stellar evolution, and dead stars including supernovae. Active galaxies and quasars are discussed. After considering what should be included in astrophysical cosmology, the author looks to the future of the science. (U.K.)

  7. Astrophysics Update 2

    CERN Document Server

    Mason, John W

    2006-01-01

    "Astrophysics Updates" is intended to serve the information needs of professional astronomers and postgraduate students about areas of astronomy, astrophysics and cosmology that are rich and active research spheres. Observational methods and the latest results of astronomical research are presented as well as their theoretical foundations and interrelations. The contributed commissioned articles are written by leading exponents in a format that will appeal to professional astronomers and astrophysicists who are interested in topics outside their own specific areas of research. This collection of timely reviews may also attract the interest of advanced amateur astronomers seeking scientifically rigorous coverage.

  8. Astrophysical opacity library

    International Nuclear Information System (INIS)

    Huebner, W.F.; Merts, A.L.; Magee, N.H. Jr.; Argo, M.F.

    1977-08-01

    The astrophysical elements opacity library includes equation of state data, various mean opacities, and 2000 values of the frequency-dependent extinction coefficients in equally spaced intervals u identical with hν/kT from 0 to 20 for 41 degeneracy parameters eta from -28 (nondegenerate) to 500 and 46 temperatures kT from 1 eV to 100 keV. Among available auxiliary quantities are the free electron density, mass density, and plasma cutoff frequency. A library-associated program can produce opacities for mixtures with up to 20 astrophysically abundant constituent elements at 4 levels of utility for the user

  9. Theoretical astrophysics an introduction

    CERN Document Server

    Bartelmann, Matthias

    2013-01-01

    A concise yet comprehensive introduction to the central theoretical concepts of modern astrophysics, presenting hydrodynamics, radiation, and stellar dynamics all in one textbook. Adopting a modular structure, the author illustrates a small number of fundamental physical methods and principles, which are sufficient to describe and understand a wide range of seemingly very diverse astrophysical phenomena and processes. For example, the formulae that define the macroscopic behavior of stellar systems are all derived in the same way from the microscopic distribution function. This function it

  10. Astrophysics in a nutshell

    CERN Document Server

    Maoz, Dan

    2016-01-01

    Winner of the American Astronomical Society's Chambliss Award, Astrophysics in a Nutshell has become the text of choice in astrophysics courses for science majors at top universities in North America and beyond. In this expanded and fully updated second edition, the book gets even better, with a new chapter on extrasolar planets; a greatly expanded chapter on the interstellar medium; fully updated facts and figures on all subjects, from the observed properties of white dwarfs to the latest results from precision cosmology; and additional instructive problem sets. Throughout, the text features the same focused, concise style and emphasis on physics intuition that have made the book a favorite of students and teachers.

  11. Introduction to Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Iliadis, Christian

    2010-01-01

    In the first lecture of this volume, we will present the basic fundamental ideas regarding nuclear processes occurring in stars. We start from stellar observations, will then elaborate on some important quantum-mechanical phenomena governing nuclear reactions, continue with how nuclear reactions proceed in a hot stellar plasma and, finally, we will provide an overview of stellar burning stages. At the end, the current knowledge regarding the origin of the elements is briefly summarized. This lecture is directed towards the student of nuclear astrophysics. Our intention is to present seemingly unrelated phenomena of nuclear physics and astrophysics in a coherent framework.

  12. Focusing telescopes in nuclear astrophysics

    International Nuclear Information System (INIS)

    Von Ballmoos, P.; Knodlseder, R.; Sazonov, S.; Griffiths, R.; Bastie, P.; Halloin, H.; Pareschi, G.; Ramsey, B.; Jensen, C.; Buis, E.J.; Ulmer, M.; Giommi, P.; Colafrancesco, S.; Comastri, A.; Barret, D.; Leising, M.; Hernanz, M.; Smith, D.; Abrosimov, N.; Smither, B.; Ubertini, P.; Olive, J.F.; Lund, N.; Pisa, A.; Courtois, P.; Roa, D.; Harrison, F.; Pareschi, G.; Frontera, F.; Von Ballmoos, P.; Barriere, N.; Rando, N.; Borde, J.; Hinglais, E.; Cledassou, R.; Duchon, P.; Sghedoni, M.; Huet, B.; Takahashi, T.; Caroli, E.; Quadrinin, L.; Buis, E.J.; Skinner, G.; Krizmanic, J.; Pareschi, G.; Loffredo, G.; Wunderer, C.; Weidenspointner, G.; Wunderer, C.; Koechlin, L.; Bignami, G.; Von Ballmoos, P.; Tueller, J.; Andritschke, T.; Laurens, A.; Evrard, J.

    2005-01-01

    The objective of this workshop is to consider the next generation of instrumentation to be required within the domain of nuclear astrophysics. A small, but growing community has been pursuing various techniques for the focusing of hard X-rays and gamma-rays with the aim of achieving a factor of up to 100 improvement in sensitivity over present technologies. Balloon flight tests of both multilayer mirrors and a Laue lens have been performed and ideas abound. At present, implementation scenarios for space missions are being studied at Esa, CNES, and elsewhere. The workshop will provide a first opportunity for this new community to meet, exchange technological know-how, discuss scientific objectives and synergies, and consolidate implementation approaches within National and European Space Science programs. This document gathers the slides of all the presentations

  13. Focusing telescopes in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Von Ballmoos, P; Knodlseder, R; Sazonov, S; Griffiths, R; Bastie, P; Halloin, H; Pareschi, G; Ramsey, B; Jensen, C; Buis, E J; Ulmer, M; Giommi, P; Colafrancesco, S; Comastri, A; Barret, D; Leising, M; Hernanz, M; Smith, D; Abrosimov, N; Smither, B; Ubertini, P; Olive, J F; Lund, N; Pisa, A; Courtois, P; Roa, D; Harrison, F; Pareschi, G; Frontera, F; Von Ballmoos, P; Barriere, N; Rando, N; Borde, J; Hinglais, E; Cledassou, R; Duchon, P; Sghedoni, M; Huet, B; Takahashi, T; Caroli, E; Quadrinin, L; Buis, E J; Skinner, G; Krizmanic, J; Pareschi, G; Loffredo, G; Wunderer, C; Weidenspointner, G; Wunderer, C; Koechlin, L; Bignami, G; Von Ballmoos, P; Tueller, J; Andritschke, T; Laurens, A; Evrard, J

    2005-07-01

    The objective of this workshop is to consider the next generation of instrumentation to be required within the domain of nuclear astrophysics. A small, but growing community has been pursuing various techniques for the focusing of hard X-rays and gamma-rays with the aim of achieving a factor of up to 100 improvement in sensitivity over present technologies. Balloon flight tests of both multilayer mirrors and a Laue lens have been performed and ideas abound. At present, implementation scenarios for space missions are being studied at Esa, CNES, and elsewhere. The workshop will provide a first opportunity for this new community to meet, exchange technological know-how, discuss scientific objectives and synergies, and consolidate implementation approaches within National and European Space Science programs. This document gathers the slides of all the presentations.

  14. New frontiers for tomorrow's world

    International Nuclear Information System (INIS)

    Kassler, P.

    1994-01-01

    The conference paper deals with new frontiers and barricades in the global economic development and their influence on fuel consumption and energy source development. Topics discussed are incremental energy supply - new frontiers, world car population - new frontiers, OPEC crude production capacity vs call on OPEC, incremental world oil demand by region 1992-2000, oil resource cost curve, progress in seismic 1983-1991, Troll picture, cost reduction in renewables, sustained growth scenario, nuclear electricity capacity - France, OECD road transport fuels - barricades, and energy taxation. 18 figs

  15. Astrophysical Russian Dolls

    OpenAIRE

    Loeb, Abraham; Imara, Nia

    2017-01-01

    Are there examples of "astrophysical Russian dolls," and what could we learn from their similarities? In this article, we list a few such examples, including disks, filaments, and clusters. We suggest that forging connections across disciplinary borders enhances our perception of beauty, while simultaneously leading to a more comprehensive understanding of the Universe.

  16. High energy astrophysics

    International Nuclear Information System (INIS)

    Shklorsky, I.S.

    1979-01-01

    A selected list of articles of accessible recent review articles and conference reports, wherein up-to-date summaries of various topics in the field of high energy astrophysics can be found, is presented. A special report outlines work done in the Soviet Union in this area. (Auth.)

  17. Ghana's cocoa frontier in transition

    DEFF Research Database (Denmark)

    Knudsen, Michael Helt; Agergaard, Jytte

    2015-01-01

    Since the first commercial planting of cocoa in Ghana more than a century ago, the production of cocoa has been a key factor in the redistribution of migrants and has played a pivotal role in the development of both sending and receiving communities. This process has been acknowledged...... Region, this article aims to examine how immigration and frontier dynamics in the Western region are contributing to livelihood transitions and small town development, and how this process is gradually becoming delinked from the production of cocoa. The article focuses on how migration dynamics interlink...... in the literature for decades. However, how migration flows have changed in response to changing livelihoods dynamics of the frontier and how this has impacted on the development of the frontier has only attracted limited attention. Based on a study of immigration to Ghana's current cocoa frontier in the Western...

  18. Encyclopedia of Astronomy and Astrophysics

    CERN Document Server

    2002-01-01

    Interstellar medium, Light, Magnetisphere, Matter, Planet Earth, Public Impact, Solar Activity, Solar Heliosphere, Solar Interior, Solar Systems, Space, Stellar Astrophysics, Stellar Populations, Telescopes, Time The Encyclopedia of Astronomy and Astrophysics covers 30 major subject areas, such as Active galaxies, Astrometry, Astrophysical theory, Atmospheres, Binary stars, Biography, Clusters, Coordinates, Cosmology, Earth, Education, Galaxies,

  19. Multi-scale data visualization for computational astrophysics and climate dynamics at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Ahern, Sean; Daniel, Jamison R; Gao, Jinzhu; Ostrouchov, George; Toedte, Ross J; Wang, Chaoli

    2006-01-01

    Computational astrophysics and climate dynamics are two principal application foci at the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL). We identify a dataset frontier that is shared by several SciDAC computational science domains and present an exploration of traditional production visualization techniques enhanced with new enabling research technologies such as advanced parallel occlusion culling and high resolution small multiples statistical analysis. In collaboration with our research partners, these techniques will allow the visual exploration of a new generation of peta-scale datasets that cross this data frontier along all axes

  20. A Study on Neutrosophic Frontier and Neutrosophic Semi-frontier in Neutrosophic Topological Spaces

    Directory of Open Access Journals (Sweden)

    P. Iswarya

    2017-02-01

    Full Text Available In this paper neutrosophic frontier and neutrosophic semi-frontier in neutrosophic topology are introduced and several of their properties, characterizations and examples are established.

  1. Indirect techniques in nuclear astrophysics

    International Nuclear Information System (INIS)

    Mukhamedzhanov, A.M.; Tribble, R.E.; Blokhintsev, L.D.; Cherubini, S.; Spitaleri, C.; Kroha, V.; Nunes, F.M.

    2005-01-01

    It is very difficult or often impossible to measure in the lab conditions nuclear cross sections at astrophysically relevant energies. That is why different indirect techniques are used to extract astrophysical information. In this talk different experimental possibilities to get astrophysical information using radioactive and stable beams will be addressed. 1. The asymptotic normalization coefficient (ANC) method. 2. Radiative neutron captures are determined by the spectroscopic factors (SP). A new experimental technique to determine the neutron SPs will be addressed. 3. 'Trojan Horse' is another unique indirect method, which allows one to extract the astrophysical factors for direct and resonant nuclear reactions at astrophysically relevant energies. (author)

  2. Scaling law in laboratory astrophysics

    International Nuclear Information System (INIS)

    Xia Jiangfan; Zhang Jie

    2001-01-01

    The use of state-of-the-art lasers makes it possible to produce, in the laboratory, the extreme conditions similar to those in astrophysical processes. The introduction of astrophysics-relevant ideas in laser-plasma interaction experiments is propitious to the understanding of astrophysical phenomena. However, the great difference between laser-produced plasma and astrophysical objects makes it awkward to model the latter by laser-plasma experiments. The author presents the physical reasons for modeling astrophysical plasmas by laser plasmas, connecting these two kinds of plasmas by scaling laws. This allows the creation of experimental test beds where observation and models can be quantitatively compared with laboratory data

  3. Astrophysics a new approach

    CERN Document Server

    Kundt, Wolfgang

    2005-01-01

    For a quantitative understanding of the physics of the universe - from the solar system through the milky way to clusters of galaxies all the way to cosmology - these edited lecture notes are perhaps among the most concise and also among the most critical ones: Astrophysics has not yet stood the redundancy test of laboratory physics, hence should be wary of early interpretations. Special chapters are devoted to magnetic and radiation processes, supernovae, disks, black-hole candidacy, bipolar flows, cosmic rays, gamma-ray bursts, image distortions, and special sources. At the same time, planet earth is viewed as the arena for life, with plants and animals having evolved to homo sapiens during cosmic time. -- This text is unique in covering the basic qualitative and quantitative tools, formulae as well as numbers, needed for the precise interpretation of frontline phenomena in astrophysical research. The author compares mainstream interpretations with new and even controversial ones he wishes to emphasize. The...

  4. Astrophysics of Red Supergiants

    Science.gov (United States)

    Levesque, Emily M.

    2017-12-01

    'Astrophysics of Red Supergiants' is the first book of its kind devoted to our current knowledge of red supergiant stars, a key evolutionary phase that is critical to our larger understanding of massive stars. It provides a comprehensive overview of the fundamental physical properties of red supergiants, their evolution, and their extragalactic and cosmological applications. It serves as a reference for researchers from a broad range of fields (including stellar astrophysics, supernovae, and high-redshift galaxies) who are interested in red supergiants as extreme stages of stellar evolution, dust producers, supernova progenitors, extragalactic metallicity indicators, members of massive binaries and mergers, or simply as compelling objects in their own right. The book is accessible to a range of experience levels, from graduate students up to senior researchers.

  5. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  6. Nuclear astrophysics at DRAGON

    International Nuclear Information System (INIS)

    Hager, U.

    2014-01-01

    The DRAGON recoil separator is located at the ISAC facility at TRIUMF, Vancouver. It is designed to measure radiative alpha and proton capture reactions of astrophysical importance. Over the last years, the DRAGON collaboration has measured several reactions using both radioactive and high-intensity stable beams. For example, the 160(a, g) cross section was recently measured. The reaction plays a role in steady-state helium burning in massive stars, where it follows the 12C(a, g) reaction. At astrophysically relevant energies, the reaction proceeds exclusively via direct capture, resulting in a low rate. In this measurement, the unique capabilities of DRAGON enabled determination not only of the total reaction rates, but also of decay branching ratios. In addition, results from other recent measurements will be presented

  7. Allen's astrophysical quantities

    CERN Document Server

    2000-01-01

    This new, fourth, edition of Allen's classic Astrophysical Quantities belongs on every astronomer's bookshelf. It has been thoroughly revised and brought up to date by a team of more than ninety internationally renowned astronomers and astrophysicists. While it follows the basic format of the original, this indispensable reference has grown to more than twice the size of the earlier editions to accommodate the great strides made in astronomy and astrophysics. It includes detailed tables of the most recent data on: - General constants and units - Atoms, molecules, and spectra - Observational astronomy at all wavelengths from radio to gamma-rays, and neutrinos - Planetary astronomy: Earth, planets and satellites, and solar system small bodies - The Sun, normal stars, and stars with special characteristics - Stellar populations - Cataclysmic and symbiotic variables, supernovae - Theoretical stellar evolution - Circumstellar and interstellar material - Star clusters, galaxies, quasars, and active galactic nuclei ...

  8. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Cardenas, M.

    1976-01-01

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  9. The new astrophysics

    International Nuclear Information System (INIS)

    Longair, M.

    1993-01-01

    The various themes developed are: radioastronomy, X-ray and gamma-ray astronomy, cosmic ray, ultraviolet, neutral hydrogen and molecular line astronomy, optical and theoretical astronomy; the large scale distribution of matter and radiation in the universe, the galaxies, stars and stellar evolution, the interstellar medium (gas, dust) and star formation, galaxies and clusters of galaxies, active galaxies and quasars, astrophysical cosmology, the astronomy of the future. 86 figs., 60 refs

  10. Frontiers in Chemical Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bowlan, Pamela Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-02

    These are slides dealing with frontiers in chemical physics. The following topics are covered: Time resolving chemistry with ultrashort pulses in the 0.1-40 THz spectral range; Example: Mid-infrared absorption spectrum of the intermediate state CH2OO; Tracking reaction dynamics through changes in the spectra; Single-shot measurement of the mid-IR absorption dynamics; Applying 2D coherent mid-IR spectroscopy to learn more about transition states; Time resolving chemical reactions at a catalysis using mid-IR and THz pulses; Studying topological insulators requires a surface sensitive probe; Nonlinear phonon dynamics in Bi2Se3; THz-pump, SHG-probe as a surface sensitive coherent 2D spectroscopy; Nanometer and femtosecond spatiotemporal resolution mid-IR spectroscopy; Coherent two-dimensional THz/mid-IR spectroscopy with 10nm spatial resolution; Pervoskite oxides as catalysts; Functionalized graphene for catalysis; Single-shot spatiotemporal measurements; Spatiotemporal pulse measurement; Intense, broad-band THz/mid-IR generation with organic crystals.

  11. On unlimited frontiers

    International Nuclear Information System (INIS)

    Graham, J.

    1985-01-01

    The political system in the United States in unique because our forefathers planned it that way. Unfortunately, this uniqueness does not always serve the interest of those who advocate large nuclear-power facilities and fuel-cycle activities involving reprocessing and breeder reactors. The influence of various political systems on the viability of the nuclear-power option is discussed. As it faces the future, the U.S. nuclear community is divided over its most appropriate courses of action. The current administration is supportive in words if not in deeds, but it is ideologically opposed to advocating the conditions needed for a thriving nuclear industry based on large light water reactors. Will the U.S. enter the new century with ''unlimited frontiers'' in many new nuclear plant designs, or will some major shift in public opinion bring back political conditions that are more compatible with large LWR facilities. This is the $64,000 question confronting the nuclear industry, which must be prepared for any eventuality. The best chance for the U.S. to regain worldwide superiority in nuclear power-technology may lie in our ability to make rapid adjustments and to offer new and advanced machines that best fit utility needs and the political conditions of their own time

  12. Astrophysical fluid dynamics

    Science.gov (United States)

    Ogilvie, Gordon I.

    2016-06-01

    > These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is `frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, including shocks and other discontinuities, are discussed. The spherical blast wave resulting from a supernova, and involving a strong shock, is a classic problem that can be solved analytically. Steady solutions with spherical or axial symmetry reveal the physics of winds and jets from stars and discs. The linearized equations determine the oscillation modes of astrophysical bodies, as well as their stability and their response to tidal forcing.

  13. Astrophysical data analysis with information field theory

    International Nuclear Information System (INIS)

    Enßlin, Torsten

    2014-01-01

    Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented

  14. Astrophysical data analysis with information field theory

    Science.gov (United States)

    Enßlin, Torsten

    2014-12-01

    Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

  15. Astrophysical data analysis with information field theory

    Energy Technology Data Exchange (ETDEWEB)

    Enßlin, Torsten, E-mail: ensslin@mpa-garching.mpg.de [Max Planck Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching, Germany and Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, D-80539 München (Germany)

    2014-12-05

    Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

  16. NASA Astrophysics Funds Strategic Technology Development

    Science.gov (United States)

    Seery, Bernard D.; Ganel, Opher; Pham, Bruce

    2016-01-01

    The COR and PCOS Program Offices (POs) reside at the NASA Goddard Space Flight Center (GSFC), serving as the NASA Astrophysics Division's implementation arm for matters relating to the two programs. One aspect of the PO's activities is managing the COR and PCOS Strategic Astrophysics Technology (SAT) program, helping mature technologies to enable and enhance future astrophysics missions. For example, the SAT program is expected to fund key technology developments needed to close gaps identified by Science and Technology Definition Teams (STDTs) planned to study several large mission concept studies in preparation for the 2020 Decadal Survey.The POs are guided by the National Research Council's "New Worlds, New Horizons in Astronomy and Astrophysics" Decadal Survey report, NASA's Astrophysics Implementation Plan, and the visionary Astrophysics Roadmap, "Enduring Quests, Daring Visions." Strategic goals include dark energy, gravitational waves, and X-ray observatories. Future missions pursuing these goals include, e.g., US participation in ESA's Euclid, Athena, and L3 missions; Inflation probe; and a large UV/Optical/IR (LUVOIR) telescope.To date, 65 COR and 71 PCOS SAT proposals have been received, of which 15 COR and 22 PCOS projects were funded. Notable successes include maturation of a new far-IR detector, later adopted by the SOFIA HAWC instrument; maturation of the H4RG near-IR detector, adopted by WFIRST; development of an antenna-coupled transition-edge superconducting bolometer, a technology deployed by BICEP2/BICEP3/Keck to measure polarization in the CMB signal; advanced UV reflective coatings implemented on the optics of GOLD and ICON, two heliophysics Explorers; and finally, the REXIS instrument on OSIRIS-REx is incorporating CCDs with directly deposited optical blocking filters developed by another SAT-funded project.We discuss our technology development process, with community input and strategic prioritization informing calls for SAT proposals and

  17. Laboratory Astrophysics Using a Spare XRS Microcalorimeter

    Science.gov (United States)

    Audley, M. Damian; Beiersdorfer, Peter; Porter, Frederick Scott; Brown, Gregory; Boyce, Kevin R.; Brekosky, Regis; Brown, Gregory V.; Gendreau, Keith C.; Gygax, John; Kahn, Steve; hide

    2000-01-01

    The XRS instrument on Astro-E is a fully self-contained microcalorimeter x-ray instrument capable of acquiring optimally filtering, and characterizing events for 32 independent pixels. With the launch of the Astro-E spacecraft, a full flight spare detector system has been integrated into a laboratory cryostat for use on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory. The detector system contains a microcalorimeter array with 32 instrumented pixels heat sunk to 60 mK using an adiabatic demagnetization refrio,erator. The instrument has a composite resolution of 8eV at 1 keV and 12eV at 6 keV with a minimum of 95% quantum efficiency. This will allow high spectral resolution, broadband observations of collisionally excited plasmas which are produced in the EBIT experiment. Unique to our instrument are exceptionally well characterized 1000 Angstrom thick aluminum on polyimide infrared blocking filters. The detailed transmission function including the edc,e fine structure of these filters has been measured in our laboratory using an erect field grating spectrometer. This will allow the instrument to perform the first broadband absolute flux measurements with the EBIT instrument. The instrument performance as well as the results of preliminary measurements will be discussed. Work performed under the auspices of the U.S. D.o.E. by Lawrence Livermore National Laboratory under contract W-7405-ENG-48 and was supported by the NASA High Energy Astrophysics Supporting Research and Technology Program.

  18. Research in nuclear astrophysics

    International Nuclear Information System (INIS)

    Lattimer, J.M.; Yahil, A.

    1989-01-01

    The interaction between nuclear theory and some outstanding problems in astrophysics is examined. We are actively researching both the astrophysics of gravitational collapse, neutron star birth, and the emission of neutrinos from supernovae, on the one hand, and the nuclear physics of the equation of state of hot, dense matter on the other hand. There is close coupling between nuclear theory and the supernova phenomenon; in fact, nuclear matter properties, especially at supernuclear densities, might be best delineated by astrophysical considerations. Our research has also focused on the neutrinos emitted from supernovae, since they are the only available observables of the internal supernova mechanism. The recent observations of neutrinos from SN 1987A proved to be in remarkable agreement with models we pioneered in the one and one half years prior to its explosion in February 1987. We have also developed a novel hydrodynamical code in which shocks are treated via Riemann resolution rather than with artificial viscosity. We propose to modify it to use implicit differencing and to include multi-group neutrino diffusion and General Relativity. In parallel, we are extending calculations of the birth of a neutron star to include convection and mass accretion, by incorporating a hydrodynamic envelope onto a hydrostatic core. In view of the possible recent discovery of a pulsar in SN1987A, we are including the effects of rotation. We are undertaking a detailed comparison of current equations of state, focusing on disagreements regarding the nuclear incompressibly, symmetry energy and specific heat. Especially important is the symmetry energy, which below nuclear density controls free proton fractions and weak interaction rates and above this density critically influences the neutron star maximum mass and binding energy. 60 refs

  19. Experimental studies of nuclear astrophysics

    International Nuclear Information System (INIS)

    He Jianjun; Zhou Xiaohong; Zhang Yuhu

    2013-01-01

    Nuclear astrophysics is an interdisciplinary subject combining micro-scale nuclear physics and macro-scale astrophysics. Its main aims are to understand the origin and evolution of the elements in the universe, the time scale of stellar evolution, the stellar environment and sites, the energy generation of stars from thermonuclear processes and its impact on stellar evolution and the mechanisms driving astrophysical phenomena, and the structure and property of compact stars. This paper presents the significance and current research status of nuclear astrophysics; we introduce some fundamental concepts, the nuclear physics input parameters required by certain astrophysics models, and some widely-used experimental approaches in nuclear astrophysics research. The potential and feasibility of research in this field using China’s current and planned large-scale scientific facilities are analyzed briefly. Finally, the prospects of the establishing a deep underground science and engineering laboratory in China are envisaged. (authors)

  20. Astrophysics in 1999

    OpenAIRE

    Trimble, V; Aschwanden, MJ

    2000-01-01

    The year 1999 saw the arrival of a star with three planets, a universe with three parameters, and a solar corona that could be heated at least three ways. In addition, there were at least three papers on every question that has ever been asked in astrophysics, from "Will the Universe expand forever?" to "Does mantle convection occur in one or two layers?" The answers generally were, "Yes," "No," and "None of the above," to each of the questions. The authors have done their best to organize th...

  1. Frontiers of finance: evolution and efficient markets.

    Science.gov (United States)

    Farmer, J D; Lo, A W

    1999-08-31

    In this review article, we explore several recent advances in the quantitative modeling of financial markets. We begin with the Efficient Markets Hypothesis and describe how this controversial idea has stimulated a number of new directions of research, some focusing on more elaborate mathematical models that are capable of rationalizing the empirical facts, others taking a completely different tack in rejecting rationality altogether. One of the most promising directions is to view financial markets from a biological perspective and, specifically, within an evolutionary framework in which markets, instruments, institutions, and investors interact and evolve dynamically according to the "law" of economic selection. Under this view, financial agents compete and adapt, but they do not necessarily do so in an optimal fashion. Evolutionary and ecological models of financial markets is truly a new frontier whose exploration has just begun.

  2. Energy not the only frontier

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-11-15

    While the push for big new machines to explore high energy frontiers makes the headlines, other avenues for physics progress are still being actively explored. To reflect these efforts, theorists and experimenters from the experiments committees for CERN's two major existing machines - the PS Proton Synchrotron and the SPS Super Proton Synchrotron – joined forces in study groups to look at long term physics perspectives. As one experimenter put it, 'there are frontiers of high complexity and high precision as well as high energy'. The groups' findings were aired at a special joint open meeting of the two committees at CERN on 31 August and 1 September.

  3. Pushing Human Frontiers

    Science.gov (United States)

    Zubrin, Robert

    2005-01-01

    With human colonization of Mars, I think you will see a higher standard of civilization, just as America set a higher standard of civilization which then promulgated back into Europe. I think that if you want to maximize human potential, you need a higher standard of civilization, and that becomes an example that benefits everyone. Without an open frontier, closed world ideologies, such as the Malthus Theory, tend to come to the forefront. It is that there are limited resources; therefore, we are all in deadly competition with each other for the limited pot. The result is tyrannical and potentially genocidal regimes, and we've already seen this in the twentieth century. There s no truth in the Malthus Theory, because human beings are the creators of their resources. With every mouth comes a pair of hands and a brain. But if it seems to be true, you have a vector in this direction, and it is extremely unfortunate. It is only in a universe of infinite resources that all humans can be brothers and sisters. The fundamental question which affects humanity s sense of itself is whether the world is changeable or fixed. Are we the makers of our world or just its inhabitants? Some people have a view that they re living at the end of history within a world that s already defined, and there is no fundamental purpose to human life because there is nothing humans can do that matters. On the other hand, if humans understand their own role as the creators of their world, that s a much more healthy point of view. It raises the dignity of humans. Indeed, if we do establish a new branch of human civilization on Mars that grows in time and potency to the point where it cannot really settle Mars, but transforms Mars, and brings life to Mars, we will prove to everyone and for all time the precious and positive nature of the human species and every member of it.

  4. The two frontiers of physics

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-05-15

    In March at Garching, near Munich, physicists from different walks of life together took another hard look at the two major frontiers of physics – the very large and the infinitesimally small. Organized jointly by CERN and the European Southern Observatory (ESO), the Garching 'Symposium on Cosmology, Astronomy and Fundamental Physics' was the second in a series launched at CERN in November 1983.

  5. Welcome to the Universe an astrophysical tour

    CERN Document Server

    DeGrasse Tyson, Neil; Gott, Richard J

    2016-01-01

    Welcome to the Universe is a personal guided tour of the cosmos by three of today's leading astrophysicists. Inspired by the enormously popular introductory astronomy course that Neil deGrasse Tyson, Michael A. Strauss, and J. Richard Gott taught together at Princeton, this book covers it all--from planets, stars, and galaxies to black holes, wormholes, and time travel. Describing the latest discoveries in astrophysics, the informative and entertaining narrative propels you from our home solar system to the outermost frontiers of space. How do stars live and die? Why did Pluto lose its planetary status? What are the prospects of intelligent life elsewhere in the universe? How did the universe begin? Why is it expanding and why is its expansion accelerating? Is our universe alone or part of an infinite multiverse? Answering these and many other questions, the authors open your eyes to the wonders of the cosmos, sharing their knowledge of how the universe works. Breathtaking in scope and stunningly illustrate...

  6. Important plasma problems in astrophysics

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1995-01-01

    In astrophysics, plasmas occur under very extreme conditions. For example, there are ultrastrong magnetic fields in neutron stars, relativistic plasmas around black holes and in jets, extremely energetic particles such as cosmic rays in the interstellar medium, extremely dense plasmas in accretion disks, and extremely large magnetic Reynolds numbers in the interstellar medium. These extreme limits for astrophysical plasmas make plasma phenomena much simpler to analyze in astrophysics than in the laboratory. An understanding of such phenomena often results in an interesting way, by simply taking the extreme limiting case of a known plasma theory. The author will describe one of the more exciting examples and will attempt to convey the excitement he felt when he was first exposed to it. However, not all plasma astrophysical phenomena are so simple. There are certain important plasma phenomena in astrophysics that have not been so easily resolved. In fact, a resolution of them is blocking significant progress in astrophysical research. They have not yet yielded to attacks by theoretical astrophysicists nor to extensive numerical simulation. The author will attempt to describe one of the more important of these plasma--astrophysical problems, and discuss why its resolution is so important to astrophysics. This significant example is fast, magnetic reconnection. Another significant example is the large-magnetic-Reynolds number magnetohydrodynamics (MHD) dynamos

  7. Computational Infrastructure for Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Smith, Michael S.; Hix, W. Raphael; Bardayan, Daniel W.; Blackmon, Jeffery C.; Lingerfelt, Eric J.; Scott, Jason P.; Nesaraja, Caroline D.; Chae, Kyungyuk; Guidry, Michael W.; Koura, Hiroyuki; Meyer, Richard A.

    2006-01-01

    A Computational Infrastructure for Nuclear Astrophysics has been developed to streamline the inclusion of the latest nuclear physics data in astrophysics simulations. The infrastructure consists of a platform-independent suite of computer codes that is freely available online at nucastrodata.org. Features of, and future plans for, this software suite are given

  8. Cyberinfrastructure for Computational Relativistic Astrophysics

    OpenAIRE

    Ott, Christian

    2012-01-01

    Poster presented at the NSF Office of Cyberinfrastructure CyberBridges CAREER PI workshop. This poster discusses the computational challenges involved in the modeling of complex relativistic astrophysical systems. The Einstein Toolkit is introduced. It is an open-source community infrastructure for numerical relativity and computational astrophysics.

  9. FOREWORD: Nuclear Physics in Astrophysics V

    Science.gov (United States)

    Auerbach, Naftali; Hass, Michael; Paul, Michael

    2012-02-01

    the conference dinner banquet at the Dan hotel. An excursion to the 'Red Canyon' in the Eilat Mountains on Wednesday afternoon was one of the social highlights of the conference. A total number of 140 scientists attended NPA5 and about 30 accompanying persons; about 25% of these were young participants (less than 36 years old). 23 participants were from Israel, and 27 were from outside of Europe (including two from Africa). The subjects covered at the conference in Eilat concentrated mainly on the spirit of the original idea - to probe experimental and theoretical activity in nuclear structure and reactions that is directly related to the physics of the Universe. There were also sessions of general interest in astrophysics, as well as a poster session on Tuesday evening featuring 40 posters. The topics included: Nuclear Structure - Theory and Experiment Big-Bang Nucleosynthesis and Formation of First Stars Stellar Reactions and Solar Neutrinos Explosive Nucleosynthesis, Radioactive Beams and Exotic Nuclei-New Facilities and Future Possibilities for Astrophysics Neutrino Physics - the Low and High-Energy Frontiers Rare events, Dark Matter, Double beta-decay, Symmetries The conference started with an excellent exposé of the progress made in the discovery of super-heavy elements and the study of their properties. The progress in this field is enormous, and this subject should be communicated to more general audiences. The role of the nuclear equation of state and of the precise determination of nuclear masses in nucleosynthesis was emphasized in several talks. The role of neutrinos in astrophysics was discussed extensively in several sessions. One of the highlights of this was the presentation about the IceCube and DeepCore detectors operating deep in the Antarctic ice. These facilities are able to detect cosmogenic neutrinos in a wide energy range, from 10 GeV to 1010 GeV. The subject of solar neutrinos was discussed in a number of talks. Topics related to properties

  10. Radiation processes in astrophysics

    CERN Document Server

    Tucker, Wallace H

    1975-01-01

    The purpose of this book is twofold: to provide a brief, simple introduction to the theory of radiation and its application in astrophysics and to serve as a reference manual for researchers. The first part of the book consists of a discussion of the basic formulas and concepts that underlie the classical and quantum descriptions of radiation processes. The rest of the book is concerned with applications. The spirit of the discussion is to present simple derivations that will provide some insight into the basic physics involved and then to state the exact results in a form useful for applications. The reader is referred to the original literature and to reviews for rigorous derivations.The wide range of topics covered is illustrated by the following table of contents: Basic Formulas for Classical Radiation Processes; Basic Formulas for Quantum Radiation Processes; Cyclotron and Synchrotron Radiation; Electron Scattering; Bremsstrahlung and Collision Losses; Radiative Recombination; The Photoelectric Effect; a...

  11. NASA's Astrophysics Data Archives

    Science.gov (United States)

    Hasan, H.; Hanisch, R.; Bredekamp, J.

    2000-09-01

    The NASA Office of Space Science has established a series of archival centers where science data acquired through its space science missions is deposited. The availability of high quality data to the general public through these open archives enables the maximization of science return of the flight missions. The Astrophysics Data Centers Coordinating Council, an informal collaboration of archival centers, coordinates data from five archival centers distiguished primarily by the wavelength range of the data deposited there. Data are available in FITS format. An overview of NASA's data centers and services is presented in this paper. A standard front-end modifyer called `Astrowbrowse' is described. Other catalog browsers and tools include WISARD and AMASE supported by the National Space Scince Data Center, as well as ISAIA, a follow on to Astrobrowse.

  12. Black-hole astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  13. Astrophysics Faces the Millennium

    Science.gov (United States)

    Trimble, Virginia

    2001-03-01

    The Medieval synthesis of Aristotelian philosophy and church doctrine, due largely to Thomas Aquinas, insisted that the universe outside the earth's atmosphere must be immutable, single-centered, fully inventoried, immaculate or perfect, including perfectly spherical, and much else that sounds strange to modern ears. The beginnings of modern astronomy can be largely described as the overthrow of these various concepts by a combination of new technologies and new ways of thinking, and many current questions in astrophysics can be directly tied to developments of those same concepts. Indeed they probably all can be, but not over time, ending with questions like: Do other stars have spots? What does it mean when quasar jets look like they are moving faster than the speed of light? Is there anything special about our star, our galaxy, our planet, or our universe? How did these all form, and what is their long-term fate?

  14. Numerical relativity beyond astrophysics

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  15. Exotic nuclei and astrophysics

    Directory of Open Access Journals (Sweden)

    Penionzhkevich Yu.

    2012-12-01

    Full Text Available In recent years, nuclear physics investigations of the laws of the microscopic world contributed significantly to extension of our knowledge of phenomena occurring in the macroscopic world (Universe and made a formidable contribution to the development of astrophysical and cosmological theories. First of all, this concerns the expanding universe model, the evolution of stars, and the abundances of elements, as well as the properties of various stars and cosmic objects, including “cold” and neutron stars, black holes, and pulsars. Without claiming to give a full account of all cosmological problems, we will dwell upon those of them that, in my opinion, have much in common with nuclear-matter properties manifesting themselves in nuclear interactions.

  16. Numerical relativity beyond astrophysics.

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  17. Astrophysics days and MHD

    International Nuclear Information System (INIS)

    Falgarone, Edith; Rieutord, Michel; Richard, Denis; Zahn, Jean-Paul; Dauchot, Olivier; Daviaud, Francois; Dubrulle, Berengere; Laval, Jean-Philippe; Noullez, Alain; Bourgoin, Mickael; Odier, Philippe; Pinton, Jean-Francois; Leveque, Emmanuel; Chainais, Pierre; Abry, Patrice; Mordant, Nicolas; Michel, Olivier; Marie, Louis; Chiffaudel, Arnaud; Daviaud, Francois; Petrelis, Francois; Fauve, Stephan; Nore, C.; Brachet, M.-E.; Politano, H.; Pouquet, A.; Leorat, Jacques; Grapin, Roland; Brun, Sacha; Delour, Jean; Arneodo, Alain; Muzy, Jean-Francois; Magnaudet, Jacques; Braza, Marianna; Boree, Jacques; Maurel, S.; Ben, L.; Moreau, J.; Bazile, R.; Charnay, G.; Lewandowski, Roger; Laveder, Dimitri; Bouchet, Freddy; Sommeria, Joel; Le Gal, P.; Eloy, C.; Le Dizes, S.; Schneider, Kai; Farge, Marie; Bottausci, Frederic; Petitjeans, Philippe; Maurel, Agnes; Carlier, Johan; Anselmet, Fabien

    2001-05-01

    This publication gathers extended summaries of presentations proposed during two days on astrophysics and magnetohydrodynamics (MHD). The first session addressed astrophysics and MHD: The cold interstellar medium, a low ionized turbulent plasma; Turbulent convection in stars; Turbulence in differential rotation; Protoplanetary disks and washing machines; gravitational instability and large structures; MHD turbulence in the sodium von Karman flow; Numerical study of the dynamo effect in the Taylor-Green eddy geometry; Solar turbulent convection under the influence of rotation and of the magnetic field. The second session addressed the description of turbulence: Should we give up cascade models to describe the spatial complexity of the velocity field in a developed turbulence?; What do we learn with RDT about the turbulence at the vicinity of a plane surface?; Qualitative explanation of intermittency; Reduced model of Navier-Stokes equations: quickly extinguished energy cascade; Some mathematical properties of turbulent closure models. The third session addressed turbulence and coherent structures: Alfven wave filamentation and formation of coherent structures in dispersive MHD; Statistical mechanics for quasi-geo-strophic turbulence: applications to Jupiter's coherent structures; Elliptic instabilities; Physics and modelling of turbulent detached unsteady flows in aerodynamics and fluid-structure interaction; Intermittency and coherent structures in a washing machine: a wavelet analysis of joint pressure/velocity measurements; CVS filtering of 3D turbulent mixing layer using orthogonal wavelets. The last session addressed experimental methods: Lagrangian velocity measurements; Energy dissipation and instabilities within a locally stretched vortex; Study by laser imagery of the generation and breakage of a compressed eddy flow; Study of coherent structures of turbulent boundary layer at high Reynolds number

  18. Nuclear physics and astrophysics

    International Nuclear Information System (INIS)

    Schramm, D.N.; Olinto, A.V.

    1992-09-01

    We have investigated a variety of research topics on the interface of nuclear physics and astrophysics during the past year. We have continued our study of dihyperon states in dense matter and have started to make a connection between their properties in the core of neutron stars with the ongoing experimental searches at Brookhaven National Laboratory. We started to build a scenario for the origin of gamma-ray bursts using the conversion of neutron stars to strange stars close to an active galactic nucleous. We have been reconsidering the constraints due to neutron star cooling rates on the equation of state for high density matter in the light, of recent findings which show that the faster direct Urca cooling process is possible for a range of nuclear compositions. We have developed a model for the formation of primordial magnetic fields due to the dynamics of the quark-hadron phase transition. Encouraged by the most recent observational developments, we have investigated the possible origin of the boron and beryllium abundances. We have greatly improved the calculations of the primordial abundances of these elements I>y augmenting the reaction networks and by updating the most recent experimental nuclear reaction rates. Our calculations have shown that the primordial abundances are much higher than previously thought but that the observed abundances cannot be explained by primordial sources alone. We have also studied the origin of the boron and beryllium abundances due to cosmic ray spallation. Finally, we have continued to address the solar neutrino problem by investigating the impact of astrophysical uncertainties on the MSW solution for a full three-family treatment of MSW mixing

  19. Nuclear physics and astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N.; Olinto, A.V.

    1992-09-01

    We have investigated a variety of research topics on the interface of nuclear physics and astrophysics during the past year. We have continued our study of dihyperon states in dense matter and have started to make a connection between their properties in the core of neutron stars with the ongoing experimental searches at Brookhaven National Laboratory. We started to build a scenario for the origin of gamma-ray bursts using the conversion of neutron stars to strange stars close to an active galactic nucleous. We have been reconsidering the constraints due to neutron star cooling rates on the equation of state for high density matter in the light, of recent findings which show that the faster direct Urca cooling process is possible for a range of nuclear compositions. We have developed a model for the formation of primordial magnetic fields due to the dynamics of the quark-hadron phase transition. Encouraged by the most recent observational developments, we have investigated the possible origin of the boron and beryllium abundances. We have greatly improved the calculations of the primordial abundances of these elements I>y augmenting the reaction networks and by updating the most recent experimental nuclear reaction rates. Our calculations have shown that the primordial abundances are much higher than previously thought but that the observed abundances cannot be explained by primordial sources alone. We have also studied the origin of the boron and beryllium abundances due to cosmic ray spallation. Finally, we have continued to address the solar neutrino problem by investigating the impact of astrophysical uncertainties on the MSW solution for a full three-family treatment of MSW mixing.

  20. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 4. A Satellite Data Analysis and CubeSat Instrument Simulator Tool for Simultaneous Multi-spacecraft Measurements of Solar Energetic Particles. Jordan Vannitsen Federico Rizzitelli Kaiti Wang Boris Segret Jyh-Ching Juang Jiun-Jih Miau.

  1. 12th International Symposium on Frontiers of Fundamental Physics

    CERN Document Server

    Michelini, Marisa; Santi, Lorenzo; FFP12; Frontiers of fundamental physics and physics education research

    2014-01-01

    In a knowledge-based society, research into fundamental physics plays a vital role not only in the enhancement of human knowledge but also in the development of new technology that affects everday life.The international symposium series Frontiers of Fundamental Physics (FFP) regularly brings together eminent scholars and researchers working in various areas in physics to exchange expertise, ideas, results, and new research perspectives. The twelfth such symposium, FFP12, took place at the University of Udine, Italy, and covered diverse fields of research: astrophysics, high energy physics and particle physics, theoretical physics, gravitation and cosmology, condensed matter physics, statistical physics, computational physics, and mathematical physics. Importantly, it also devoted a great deal of attention to physics education research, teacher training in modern physics, and popularization of physics. The high scientific level of FFP12 was guaranteed by the careful selection made by scientific coordinators fr...

  2. The low-energy frontier of particle physics

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2010-02-01

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  3. Nuclear astrophysics with radioactive beams

    International Nuclear Information System (INIS)

    Bertulani, C.A.; Gade, A.

    2010-01-01

    The quest to comprehend how nuclear processes influence astrophysical phenomena is driving experimental and theoretical research programs worldwide. One of the main goals in nuclear astrophysics is to understand how energy is generated in stars, how elements are synthesized in stellar events and what the nature of neutron stars is. New experimental capabilities, the availability of radioactive beams and increased computational power paired with new astronomical observations have advanced the present knowledge. This review summarizes the progress in the field of nuclear astrophysics with a focus on the role of indirect methods and reactions involving beams of rare isotopes.

  4. Nuclear Astrophysics Experiments at CIAE

    International Nuclear Information System (INIS)

    Liu Weiping; Li Zhihong; Bai Xixiang; Lian Gang; Guo Bing; Zeng, Sheng; Yan Shengquan; Wang Baoxiang; Shu Nengchuan; Wu Kaisu; Chen Yongshou

    2005-01-01

    This paper describes nuclear astrophysical studies using the unstable ion beam facility GIRAFFE. We measured the angular distributions for some low energy reactions, such as 7 Be(d, n) 8 B, 11 C(d, n) 12 N, 8 Li(d, n) 9 Be and 8 Li(d, p) 9 Li in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of 7 Be(p, γ) 8 B, 11 C(p, γ) 12 N, 8 Li(n, γ) 9 Li at astrophysically relevant energies

  5. Energy not the only frontier

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    While the push for big new machines to explore high energy frontiers makes the headlines, other avenues for physics progress are still being actively explored. To reflect these efforts, theorists and experimenters from the experiments committees for CERN's two major existing machines - the PS Proton Synchrotron and the SPS Super Proton Synchrotron – joined forces in study groups to look at long term physics perspectives. As one experimenter put it, 'there are frontiers of high complexity and high precision as well as high energy'. The groups' findings were aired at a special joint open meeting of the two committees at CERN on 31 August and 1 September

  6. Frontier Scientists use Modern Media

    Science.gov (United States)

    O'connell, E. A.

    2013-12-01

    Engaging Americans and the international community in the excitement and value of Alaskan Arctic discovery is the goal of Frontier Scientists. With a changing climate, resources of polar regions are being eyed by many nations. Frontier Scientists brings the stories of field scientists in the Far North to the public. With a website, an app, short videos, and social media channels; FS is a model for making connections between the public and field scientists. FS will demonstrate how academia, web content, online communities, evaluation and marketing are brought together in a 21st century multi-media platform, how scientists can maintain their integrity while engaging in outreach, and how new forms of media such as short videos can entertain as well as inspire.

  7. Energy not the only frontier

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    In the major world areas active In high energy physics, proposals have been prepared for new machines to manufacture intense beams of strongly interacting particles (hadrons) to complement the physics coming in from the high energy frontier. An information session on these plans for intense hadron facilities was included in the Third International Conference on the Intersections between Particle and Nuclear Physics, held in Rockport, Maine, in May

  8. The two frontiers of physics

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    In March at Garching, near Munich, physicists from different walks of life together took another hard look at the two major frontiers of physics – the very large and the infinitesimally small. Organized jointly by CERN and the European Southern Observatory (ESO), the Garching 'Symposium on Cosmology, Astronomy and Fundamental Physics' was the second in a series launched at CERN in November 1983

  9. Atoms in astrophysics

    CERN Document Server

    Eissner, W; Hummer, D; Percival, I

    1983-01-01

    It is hard to appreciate but nevertheless true that Michael John Seaton, known internationally for the enthusiasm and skill with which he pursues his research in atomic physics and astrophysics, will be sixty years old on the 16th of January 1983. To mark this occasion some of his colleagues and former students have prepared this volume. It contains articles that de­ scribe some of the topics that have attracted his attention since he first started his research work at University College London so many years ago. Seaton's association with University College London has now stretched over a period of some 37 years, first as an undergraduate student, then as a research student, and then, successively, as Assistant Lecturer, Lecturer, Reader, and Professor. Seaton arrived at University College London in 1946 to become an undergraduate in the Physics Department, having just left the Royal Air Force in which he had served as a navigator in the Pathfinder Force of Bomber Command. There are a number of stories of ho...

  10. Photonuclear reactions: astrophysical implications

    International Nuclear Information System (INIS)

    Nedorezov, V.G.

    2005-01-01

    Full text: Brief review on astrophysical aspects in photonuclear studies is presented. Main attention is paid on the two kind experiments. The first one was performed at ESRF by GRAAL collaboration using the back scattering laser photons technique to study light speed anisotropy with respect to the dipole of the Cosmic Microwave Background (CMB) radiation. This is a modern analog of the Michelson - Morley experiment. The results obtained are not only methologically different from those of the above mentioned experiments but also provide stronger constrains on the light speed anisotropy in CMB frame. Second subject is related to the electron scattering on exotic nuclei which can play significant role in explosive phenomena such as novae, supernovae and neutron stars. Such approach may be considered as the alternative to traditional low energy accelerator experiments. Exotic nuclei for these purposes can be obtained at CSI (ELISe project). The experiment is foreseen to be installed at the New Experimental Storage Ring (NESR) at RAIR where cooled secondary beams of radioactive ions will collide with an intense electron beam circulating in a small electron storage beam

  11. Astrophysical implications of periodicity

    International Nuclear Information System (INIS)

    Muller, R.A.

    1988-01-01

    Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed

  12. Nuclear physics and astrophysics

    International Nuclear Information System (INIS)

    Schramm, D.N.; Olinto, A.V.

    1993-06-01

    The authors report on recent progress of research at the interface of nuclear physics and astrophysics. During the past year, the authors continued to work on Big Bang and stellar nucleosynthesis, the solar neutrino problem, the equation of state for dense matter, the quark-hadron phase transition, and the origin of gamma-ray bursts; and began studying the consequences of nuclear reaction rates in the presence of strong magnetic fields. They have shown that the primordial production of B and Be cannot explain recent detections of these elements in halo stars and have looked at spallation as the likely source of these elements. By looking at nucleosynthesis with inhomogeneous initial conditions, they concluded that the Universe must have been very smooth before nucleosynthesis. They have also constrained neutrino oscillations and primordial magnetic fields by Big Bang nucleosynthesis. On the solar neutrino problem, they have analyzed the implications of the SAGE and GALLEX experiments. They also showed that the presence of dibaryons in neutron stars depends weakly on uncertainties of nuclear equations of state. They have started to investigate the consequences of strong magnetic fields on nuclear reactions and implications for neutron star cooling and supernova nucleosynthesis

  13. Bioactive glasses: Frontiers and challenges

    Directory of Open Access Journals (Sweden)

    Larry L. Hench

    2015-11-01

    Full Text Available Bioactive glasses were discovered in 1969 and provided for the first time an alternative to nearly inert implant materials. Bioglass formed a rapid, strong and stable bond with host tissues. This article examines the frontiers of research crossed to achieve clinical use of bioactive glasses and glass-ceramics. In the 1980’s it was discovered that bioactive glasses could be used in particulate form to stimulate osteogenesis, which thereby led to the concept of regeneration of tissues. Later, it was discovered that the dissolution ions from the glasses behaved like growth factors, providing signals to the cells. This article summarizes the frontiers of knowledge crossed during four eras of development of bioactive glasses that have led from concept of bioactivity to widespread clinical and commercial use, with emphasis on the first composition, 45S5 Bioglass®. The four eras are: a discovery; b clinical application; c tissue regeneration; and d innovation. Questions still to be answered for the fourth era are included to stimulate innovation in the field and exploration of new frontiers that can be the basis for a general theory of bioactive stimulation of regeneration of tissues and application to numerous clinical needs.

  14. Astrophysics science operations - Near-term plans and vision

    Science.gov (United States)

    Riegler, Guenter R.

    1991-01-01

    Astrophysics science operations planned by the Science Operations branch of NASA Astrophysics Division for the 1990s for the purpose of gathering spaceborne astronomical data are described. The paper describes the near-future plans of the Science Operations in the areas of the preparation of the proposal; the planning and execution of spaceborne observations; the collection, processing, and analysis data; and the dissemination of results. Also presented are concepts planned for introduction at the beginning of the 20th century, including the concepts of open communications, transparent instrument and observatory operations, a spiral requirements development method, and an automated research assistant.

  15. Goddard's Astrophysics Science Divsion Annual Report 2014

    Science.gov (United States)

    Weaver, Kimberly (Editor); Reddy, Francis (Editor); Tyler, Pat (Editor)

    2015-01-01

    The Astrophysics Science Division (ASD, Code 660) is one of the world's largest and most diverse astronomical organizations. Space flight missions are conceived, built and launched to observe the entire range of the electromagnetic spectrum, from gamma rays to centimeter waves. In addition, experiments are flown to gather data on high-energy cosmic rays, and plans are being made to detect gravitational radiation from space-borne missions. To enable these missions, we have vigorous programs of instrument and detector development. Division scientists also carry out preparatory theoretical work and subsequent data analysis and modeling. In addition to space flight missions, we have a vibrant suborbital program with numerous sounding rocket and balloon payloads in development or operation. The ASD is organized into five labs: the Astroparticle Physics Lab, the X-ray Astrophysics Lab, the Gravitational Astrophysics Lab, the Observational Cosmology Lab, and the Exoplanets and Stellar Astrophysics Lab. The High Energy Astrophysics Science Archive Research Center (HEASARC) is an Office at the Division level. Approximately 400 scientists and engineers work in ASD. Of these, 80 are civil servant scientists, while the rest are resident university-based scientists, contractors, postdoctoral fellows, graduate students, and administrative staff. We currently operate the Swift Explorer mission and the Fermi Gamma-ray Space Telescope. In addition, we provide data archiving and operational support for the XMM mission (jointly with ESA) and the Suzaku mission (with JAXA). We are also a partner with Caltech on the NuSTAR mission. The Hubble Space Telescope Project is headquartered at Goddard, and ASD provides Project Scientists to oversee operations at the Space Telescope Science Institute. Projects in development include the Neutron Interior Composition Explorer (NICER) mission, an X-ray timing experiment for the International Space Station; the Transiting Exoplanet Sky Survey (TESS

  16. An introduction to observational astrophysics

    CERN Document Server

    Gallaway, Mark

    2016-01-01

    Observational Astrophysics follows the general outline of an astrophysics undergraduate curriculum targeting practical observing information to what will be covered at the university level. This includes the basics of optics and coordinate systems to the technical details of CCD imaging, photometry, spectography and radio astronomy.  General enough to be used by students at a variety of institutions and advanced enough to be far more useful than observing guides targeted at amateurs, the author provides a comprehensive and up-to-date treatment of observational astrophysics at undergraduate level to be used with a university’s teaching telescope.  The practical approach takes the reader from basic first year techniques to those required for a final year project. Using this textbook as a resource, students can easily become conversant in the practical aspects of astrophysics in the field as opposed to the classroom.

  17. Recent progress on astrophysical opacity

    International Nuclear Information System (INIS)

    Rogers, F.J.; Iglesias, C.A.

    1992-08-01

    Improvements in the calculation of the opacity of astrophysical plasmas has helped to resolve several long-standing puzzles in the modeling of variable stars. The most significant opacity enhancements over the Los Alamos Astrophysical Library (LAOL) are due to improvements in the equation of state and atomic physics. Comparison with experiment has corroborated the predicted large opacity increases due to transitions in M-shell iron. We give a summary of recent developments

  18. An introduction to astrophysical hydrodynamics

    CERN Document Server

    Shore, Steven N

    1992-01-01

    This book is an introduction to astrophysical hydrodynamics for both astronomy and physics students. It provides a comprehensive and unified view of the general problems associated with fluids in a cosmic context, with a discussion of fluid dynamics and plasma physics. It is the only book on hydrodynamics that addresses the astrophysical context. Researchers and students will find this work to be an exceptional reference. Contents include chapters on irrotational and rotational flows, turbulence, magnetohydrodynamics, and instabilities.

  19. Minicourses in Astrophysics, Modular Approach, Vol. I.

    Science.gov (United States)

    Illinois Univ., Chicago.

    This is the first volume of a two-volume minicourse in astrophysics. It contains chapters on the following topics: planetary atmospheres; X-ray astronomy; radio astrophysics; molecular astrophysics; and gamma-ray astrophysics. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are included with…

  20. Relativistic astrophysics and theory of gravity

    International Nuclear Information System (INIS)

    Zel'dovich, Ya.B.

    1982-01-01

    A brief historical review of the development of astrophysical science in the State Astrophysical Institute named after Shternberg (SAISh) has been given in a popular form. The main directions of the SAISh astrophysical investigations have been presented: relativistic theory of gravity, relativistic astrophysics of interplanetary medium and cosmology

  1. Fundamental Questions in Astrophysics: Guidelines for Future UV Observatories

    CERN Document Server

    Gómez de Castro, Ana I

    2006-01-01

    Modern astrophysics is a mature science that has evolved from its early phase of discovery and classification to a physics-oriented discipline focused in finding answers to fundamental problems ranging from cosmology to the origin and diversity of life-sustainable systems in the Universe. For this very reason, progress of modern astrophysics requires the access to the electromagnetic spectrum in the broadest energy range. The Ultraviolet is a fundamental energy domain since it is one of the most powerful tool to study plasmas at temperatures in the 3,000-300,000~K range as well as electronic transitions of the most abundant molecules in the Universe. Moreover, the UV radiation field is a powerful astrochemical and photoionizing agent. This book describes the fundamental problems in modern astrophysics that cannot progress without easy and wide-spread access to modern UV instrumentation.

  2. General Astrophysics with the HabEx Workhorse Camera

    Science.gov (United States)

    Stern, Daniel; Clarke, John; Gaudi, B. Scott; Kiessling, Alina; Krause, Oliver; Martin, Stefan; Scowen, Paul; Somerville, Rachel; HabEx STDT

    2018-01-01

    The Habitable Exoplanet Imaging Mission (HabEx) concept has been designed to enable an extensive suite of science, broadly put under the rubric of General Astrophysics, in addition to its exoplanet direct imaging science. General astrophysics directly addresses multiple NASA programmatic branches, and HabEx will enable investigations ranging from cosmology, to galaxy evolution, to stellar population studies, to exoplanet transit spectroscopy, to Solar System studies. This poster briefly describes one of the two primary HabEx General Astrophysics instruments, the HabEx Workhorse Camera (HWC). HWC will be a dual-detector UV-to-near-IR imager and multi-object grism spectrometer with a microshutter array and a moderate (3' x 3') field-of-view. We detail some of the key science we expect HWC to undertake, emphasizing unique capabilities enabled by a large-aperture, highly stable space-borne platform at these wavelengths.

  3. NASA Astrophysics Technology Needs

    Science.gov (United States)

    Stahl, H. Philip

    2012-01-01

    July 2010, NASA Office of Chief Technologist (OCT) initiated an activity to create and maintain a NASA integrated roadmap for 15 key technology areas which recommend an overall technology investment strategy and prioritize NASA?s technology programs to meet NASA?s strategic goals. Science Instruments, Observatories and Sensor Systems(SIOSS) roadmap addresses technology needs to achieve NASA?s highest priority objectives -- not only for the Science Mission Directorate (SMD), but for all of NASA.

  4. Network frontier as a metaphor and myth

    Directory of Open Access Journals (Sweden)

    N V Plotichkina

    2017-12-01

    Full Text Available This article considers spatial metaphors of the Internet and the possibility to extrapolate the frontier thesis of F. Turner on the electronic space. The authors believe that information and communication technologies and the digital world have become new spaces for the expansion of states or individuals. That is why there are ongoing scientific debates on the limits and potential of western and electronic frontiers’ metaphors for analytical description of the digital space. The metaphor of the Internet as a western frontier is quite controversial; many authors prefer the electronic frontier analogy as more heuristic and valid for constructing metaphors of the digital reality. The network frontier is defined as a dynamic, elastic and permeable border of social and cultural practices of the network society. The authors estimate the heuristic potential of the concept ‘network frontier’ developed on the basis of integration of the frontier theory and the concept ‘network society’, taking into account the effects of globalization for the study of elastic, permeable and movable border of the network landscape. In the digital world, the spatiality transforms, the geography of the Internet network determines the metamorphosis of the frontier as a contact zone between online and offline spaces, which is dynamic, innovative, encourages mobility, and its permeability depends on the digital competence of citizens. The authors explain the mythology of western and electronic frontier; name the main network frontier myths related to the rhetoric of western frontier myth; describe the main components of the western frontier myth associated with the idea of American exceptionalism; and conclude with the identification of nowadays myths about frontier-men and the online space they master.

  5. Old Borders and New Bordering Capabilities: Cities as Frontier Zones

    Directory of Open Access Journals (Sweden)

    Saskia Sassen

    2015-12-01

    Full Text Available The global city is a new frontier zone. Deregulation, privatization, and new fiscal and monetary policies create the formal instruments to construct their equivalent of the old military “fort”. The city is also a strategic frontier zone for those who lack power, and allows the making of informal politics. At the same time the border is a mix of regimes, marked by protections and opportunities for corporations and high-level professionals, and implies confinement, capture and detention for migrants. The essay discusses the transformation of the city in a frontier zone and analyses the separation between the capabilities entailed by territoriality and the geographic territory tout court. The analysis focuses on the effects of neoliberal policies that, far from making this a borderless world, have actually multiplied the bordered spaces that allow firms and markets to move across conventional borders. Cities are therefore one of the key sites where new neoliberal norms are made and where new identities emerge.

  6. High energy astrophysics. An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Courvoisier, Thierry J.L. [Geneva Univ., Versoix (Switzerland). ISDC, Data Centre for Astrophysics

    2013-07-01

    Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

  7. Vikings and the Western Frontier

    OpenAIRE

    Wienberg, Jes

    2015-01-01

    The article investigates how and why the Vikings became world-famous. The point of departure is the World Exposition in Chicago in 1893, where an icon for the Viking, a replica of the Gokstad ship, arrived the very same day as Frederick Jackson Turner presented his frontier thesis. The origin of the word Viking, the romantic revival of the Viking, the creation of the Viking Age and the criticism of the Viking and the Viking Age is discussed. Finally the article argues that the Viking and the ...

  8. South African Homelands as Frontiers

    DEFF Research Database (Denmark)

    of frontier zones, the homelands emerge as areas in which the future of the South African postcolony is being renegotiated, contested and remade with hyper-real intensity. This is so because the many fault lines left over from apartheid (its loose ends, so to speak) – between white and black; between...... in these settings that the postcolonial promise of liberation and freedom must face its test. As such, the book offers highly nuanced and richly detailed analyses that go to the heart of the diverse dilemmas of post-apartheid South Africa as a whole, but simultaneously also provides in condensed form an extended...

  9. New Frontiers of Land Control

    DEFF Research Database (Denmark)

    Lee Peluso, Nancy; Lund, Christian

    2011-01-01

    rights, and territories created, extracted, produced, or protected on land. Primitive and on-going forms of accumulation, frontiers, enclosures, territories, grabs, and racializations have all been associated with mechanisms for land control. Agrarian environments have been transformed by processes of de...... analytic tools that had seemed to have timeless applicability with new frameworks, concepts, and theoretical tools. What difference does land control make? These contributions to the debates demonstrate that the answers have been shaped by conflicts, contexts, histories, and agency, as land has been...

  10. New frontiers in PDF determination

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Parton Distribution Functions (PDFs) are a crucial input at the LHC, their uncertainty often being the limiting factor in the accuracy of theoretical predictions. At the same time the LHC is delivering a number of precise measurements that have the potential to greatly constrain these functions. I will give an overview on the theory behind and on the state of the art of PDF determination. I will then mention the new theoretical and methodological challenges in modern PDF fits and explore the precision frontiers opened by the accuracy of the LHC data.

  11. Fundamental Physics at the Intensity Frontier

    CERN Document Server

    Hewett, J.L.; Brock, R.; Butler, J.N.; Casey, B.C.K.; Collar, J.; de Gouvea, A.; Essig, R.; Grossman, Y.; Haxton, W.; Jaros, J.A.; Jung, C.K.; Lu, Z.T.; Pitts, K.; Ligeti, Z.; Patterson, J.R.; Ramsey-Musolf, M.; Ritchie, J.L.; Roodman, A.; Scholberg, K.; Wagner, C.E.M.; Zeller, G.P.; Aefsky, S.; Afanasev, A.; Agashe, K.; Albright, C.; Alonso, J.; Ankenbrandt, C.; Aoki, M.; Arguelles, C.A.; Arkani-Hamed, N.; Armendariz, J.R.; Armendariz-Picon, C.; Arrieta Diaz, E.; Asaadi, J.; Asner, D.M.; Babu, K.S.; Bailey, K.; Baker, O.; Balantekin, B.; Baller, B.; Bass, M.; Batell, B.; Beacham, J.; Behr, J.; Berger, N.; Bergevin, M.; Berman, E.; Bernstein, R.; Bevan, A.J.; Bishai, M.; Blanke, M.; Blessing, S.; Blondel, A.; Blum, T.; Bock, G.; Bodek, A.; Bonvicini, G.; Bossi, F.; Boyce, J.; Breedon, R.; Breidenbach, M.; Brice, S.J.; Briere, R.A.; Brodsky, S.; Bromberg, C.; Bross, A.; Browder, T.E.; Bryman, D.A.; Buckley, M.; Burnstein, R.; Caden, E.; Campana, P.; Carlini, R.; Carosi, G.; Castromonte, C.; Cenci, R.; Chakaberia, I.; Chen, Mu-Chun; Cheng, C.H.; Choudhary, B.; Christ, N.H.; Christensen, E.; Christy, M.E.; Chupp, T.E.; Church, E.; Cline, D.B.; Coan, T.E.; Coloma, P.; Comfort, J.; Coney, L.; Cooper, J.; Cooper, R.J.; Cowan, R.; Cowen, D.F.; Cronin-Hennessy, D.; Datta, A.; Davies, G.S.; Demarteau, M.; DeMille, D.P.; Denig, A.; Dermisek, R.; Deshpande, A.; Dewey, M.S.; Dharmapalan, R.; Dhooghe, J.; Dietrich, M.R.; Diwan, M.; Djurcic, Z.; Dobbs, S.; Duraisamy, M.; Dutta, Bhaskar; Duyang, H.; Dwyer, D.A.; Eads, M.; Echenard, B.; Elliott, S.R.; Escobar, C.; Fajans, J.; Farooq, S.; Faroughy, C.; Fast, J.E.; Feinberg, B.; Felde, J.; Feldman, G.; Fierlinger, P.; Fileviez Perez, P.; Filippone, B.; Fisher, P.; Flemming, B.T.; Flood, K.T.; Forty, R.; Frank, M.J.; Freyberger, A.; Friedland, A.; Gandhi, R.; Ganezer, K.S.; Garcia, A.; Garcia, F.G.; Gardner, S.; Garrison, L.; Gasparian, A.; Geer, S.; Gehman, V.M.; Gershon, T.; Gilchriese, M.; Ginsberg, C.; Gogoladze, I.; Gonderinger, M.; Goodman, M.; Gould, H.; Graham, M.; Graham, P.W.; Gran, R.; Grange, J.; Gratta, G.; Green, J.P.; Greenlee, H.; Group, R.C.; Guardincerri, E.; Gudkov, V.; Guenette, R.; Haas, A.; Hahn, A.; Han, T.; Handler, T.; Hardy, J.C.; Harnik, R.; Harris, D.A.; Harris, F.A.; Harris, P.G.; Hartnett, J.; He, B.; Heckel, B.R.; Heeger, K.M.; Henderson, S.; Hertzog, D.; Hill, R.; Hinds, E.A.; Hitlin, D.G.; Holt, R.J.; Holtkamp, N.; Horton-Smith, G.; Huber, P.; Huelsnitz, W.; Imber, J.; Irastorza, I.; Jaeckel, J.; Jaegle, I.; James, C.; Jawahery, A.; Jensen, D.; Jessop, C.P.; Jones, B.; Jostlein, H.; Junk, T.; Kagan, A.L.; Kalita, M.; Kamyshkov, Y.; Kaplan, D.M.; Karagiorgi, G.; Karle, A.; Katori, T.; Kayser, B.; Kephart, R.; Kettell, S.; Kim, Y.K.; Kirby, M.; Kirch, K.; Klein, J.; Kneller, J.; Kobach, A.; Kohl, M.; Kopp, J.; Kordosky, M.; Korsch, W.; Kourbanis, I.; Krisch, A.D.; Krizan, P.; Kronfeld, A.S.; Kulkarni, S.; Kumar, K.S.; Kuno, Y.; Kutter, T.; Lachenmaier, T.; Lamm, M.; Lancaster, J.; Lancaster, M.; Lane, C.; Lang, K.; Langacker, P.; Lazarevic, S.; Le, T.; Lee, K.; Lesko, K.T.; Li, Y.; Lindgren, M.; Lindner, A.; Link, J.; Lissauer, D.; Littenberg, L.S.; Littlejohn, B.; Liu, C.Y.; Loinaz, W.; Lorenzon, W.; Louis, W.C.; Lozier, J.; Ludovici, L.; Lueking, L.; Lunardini, C.; MacFarlane, D.B.; Machado, P.A.N.; Mackenzie, P.B.; Maloney, J.; Marciano, W.J.; Marsh, W.; Marshak, M.; Martin, J.W.; Mauger, C.; McFarland, K.S.; McGrew, C.; McLaughlin, G.; McKeen, D.; McKeown, R.; Meadows, B.T.; Mehdiyev, R.; Melconian, D.; Merkel, H.; Messier, M.; Miller, J.P.; Mills, G.; Minamisono, U.K.; Mishra, S.R.; Mocioiu, I.; Sher, S.Moed; Mohapatra, R.N.; Monreal, B.; Moore, C.D.; Morfin, J.G.; Mousseau, J.; Moustakas, L.A.; Mueller, G.; Mueller, P.; Muether, M.; Mumm, H.P.; Munger, C.; Murayama, H.; Nath, P.; Naviliat-Cuncin, O.; Nelson, J.K.; Neuffer, D.; Nico, J.S.; Norman, A.; Nygren, D.; Obayashi, Y.; O'Connor, T.P.; Okada, Y.; Olsen, J.; Orozco, L.; Orrell, J.L.; Osta, J.; Pahlka, B.; Paley, J.; Papadimitriou, V.; Papucci, M.; Parke, S.; Parker, R.H.; Parsa, Z.; Partyka, K.; Patch, A.; Pati, J.C.; Patterson, R.B.; Pavlovic, Z.; Paz, Gil; Perdue, G.N.; Perevalov, D.; Perez, G.; Petti, R.; Pettus, W.; Piepke, A.; Pivovaroff, M.; Plunkett, R.; Polly, C.C.; Pospelov, M.; Povey, R.; Prakesh, A.; Purohit, M.V.; Raby, S.; Raaf, J.L.; Rajendran, R.; Rajendran, S.; Rameika, G.; Ramsey, R.; Rashed, A.; Ratcliff, B.N.; Rebel, B.; Redondo, J.; Reimer, P.; Reitzner, D.; Ringer, F.; Ringwald, A.; Riordan, S.; Roberts, B.L.; Roberts, D.A.; Robertson, R.; Robicheaux, F.; Rominsky, M.; Roser, R.; Rosner, J.L.; Rott, C.; Rubin, P.; Saito, N.; Sanchez, M.; Sarkar, S.; Schellman, H.; Schmidt, B.; Schmitt, M.; Schmitz, D.W.; Schneps, J.; Schopper, A.; Schuster, P.; Schwartz, A.J.; Schwarz, M.; Seeman, J.; Semertzidis, Y.K.; Seth, K.K.; Shafi, Q.; Shanahan, P.; Sharma, R.; Sharpe, S.R.; Shiozawa, M.; Shiltsev, V.; Sigurdson, K.; Sikivie, P.; Singh, J.; Sivers, D.; Skwarnicki, T.; Smith, N.; Sobczyk, J.; Sobel, H.; Soderberg, M.; Song, Y.H.; Soni, A.; Souder, P.; Sousa, A.; Spitz, J.; Stancari, M.; Stavenga, G.C.; Steffen, J.H.; Stepanyan, S.; Stoeckinger, D.; Stone, S.; Strait, J.; Strassler, M.; Sulai, I.A.; Sundrum, R.; Svoboda, R.; Szczerbinska, B.; Szelc, A.; Takeuchi, T.; Tanedo, P.; Taneja, S.; Tang, J.; Tanner, D.B.; Tayloe, R.; Taylor, I.; Thomas, J.; Thorn, C.; Tian, X.; Tice, B.G.; Tobar, M.; Tolich, N.; Toro, N.; Towner, I.S.; Tsai, Y.; Tschirhart, R.; Tunnell, C.D.; Tzanov, M.; Upadhye, A.; Urheim, J.; Vahsen, S.; Vainshtein, A.; Valencia, E.; Van de Water, R.G.; Van de Water, R.S.; Velasco, M.; Vogel, J.; Vogel, P.; Vogelsang, W.; Wah, Y.W.; Walker, D.; Weiner, N.; Weltman, A.; Wendell, R.; Wester, W.; Wetstein, M.; White, C.; Whitehead, L.; Whitmore, J.; Widmann, E.; Wiedemann, G.; Wilkerson, J.; Wilkinson, G.; Wilson, P.; Wilson, R.J.; Winter, W.; Wise, M.B.; Wodin, J.; Wojcicki, S.; Wojtsekhowski, B.; Wongjirad, T.; Worcester, E.; Wurtele, J.; Xin, T.; Xu, J.; Yamanaka, T.; Yamazaki, Y.; Yavin, I.; Yeck, J.; Yeh, M.; Yokoyama, M.; Yoo, J.; Young, A.; Zimmerman, E.; Zioutas, K.; Zisman, M.; Zupan, J.; Zwaska, R.; Intensity Frontier Workshop

    2012-01-01

    The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.

  12. Frontier differences and the global malmquist index

    DEFF Research Database (Denmark)

    Asmild, Mette

    2015-01-01

    This chapter reviews different ways of comparing the efficiency frontiers for subgroups within a data set, specifically program efficiency, the metatechnology (or technology gap) ratio and the global frontier difference index. The latter is subsequently used to define a global Malmquist index...

  13. JILA Science | Exploring the frontiers of physics

    Science.gov (United States)

    print logo Main menu Research Research Areas Research Highlights JILA Discoveries JILA Physics Frontier Institutes Give to JILA Search form Search Search Advanced JILA Sites: JILA Physics Frontier Center JILA Molecular Physics Biophysics Chemical Physics Laser Physics Nanoscience Precision Measurement Quantum

  14. Recent results in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Coc, Alain; Kiener, Juergen [CNRS/IN2P3 et Universite Paris Sud 11, UMR 8609, Centre de Sciences Nucleaires et de Sciences de la Matiere (CSNSM), Orsay Campus (France); Hammache, Fairouz [CNRS/IN2P3 et Universite Paris Sud 11, UMR 8608, Institut de Physique Nucleaire d' Orsay (IPNO), Orsay Campus (France)

    2015-03-01

    In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified, e.g., {sup 12}C(α, γ){sup 16}O for stellar evolution, or {sup 13}C(α, n){sup 16}O and {sup 22}Ne(α, n){sup 25}Mg as neutron sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear reaction rates now includes the associated rate uncertainties that are used in astrophysical models to i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further experimental investigation. Sometimes direct cross section measurements are possible, but more generally the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are often overlooked but are also important for nuclear astrophysics, e.g., in gamma-ray emission from solar flares or in the interaction of cosmic rays with matter, and also motivate laboratory experiments. Finally, we show that beyond the historical motivations of nuclear astrophysics, understanding i) the energy sources that drive stellar evolution and ii) the origin of the elements can also be used to give new insights into physics beyond the standard model. (orig.)

  15. Recent results in nuclear astrophysics

    International Nuclear Information System (INIS)

    Coc, Alain; Kiener, Juergen; Hammache, Fairouz

    2015-01-01

    In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified, e.g., 12 C(α, γ) 16 O for stellar evolution, or 13 C(α, n) 16 O and 22 Ne(α, n) 25 Mg as neutron sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear reaction rates now includes the associated rate uncertainties that are used in astrophysical models to i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further experimental investigation. Sometimes direct cross section measurements are possible, but more generally the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are often overlooked but are also important for nuclear astrophysics, e.g., in gamma-ray emission from solar flares or in the interaction of cosmic rays with matter, and also motivate laboratory experiments. Finally, we show that beyond the historical motivations of nuclear astrophysics, understanding i) the energy sources that drive stellar evolution and ii) the origin of the elements can also be used to give new insights into physics beyond the standard model. (orig.)

  16. Highlights of the NASA particle astrophysics program

    Energy Technology Data Exchange (ETDEWEB)

    Jones, William Vernon, E-mail: w.vernon.jones@nasa.gov [Astrophysics Division DH000, Science Mission Directorate, NASA Headquarters, Washington DC (United States)

    2014-07-01

    The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

  17. Highlights of the NASA particle astrophysics program

    International Nuclear Information System (INIS)

    Jones, William Vernon

    2014-01-01

    The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

  18. Astrophysics a very short introduction

    CERN Document Server

    Binney, James

    2016-01-01

    Astrophysics is the physics of the stars, and more widely the physics of the Universe. It enables us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the cosmos as a whole. In this Very Short Introduction, the leading astrophysicist James Binney shows how the field of astrophysics has expanded rapidly in the past century, with vast quantities of data gathered by telescopes exploiting all parts of the electromagnetic spectrum, combined with the rapid advance of computing power, which has allowed increasingly effective mathematical modelling. He illustrates how the application of fundamental principles of physics - the consideration of energy and mass, and momentum - and the two pillars of relativity and quantum mechanics, has provided insights into phenomena ranging from rapidly spinning millisecond pulsars to the collision of giant spiral galaxies. This is a clear, rigorous introduction to astrophysics for those keen to cut their teeth on a conceptual trea...

  19. Magnetohydrodynamic models of astrophysical jets

    International Nuclear Information System (INIS)

    Beskin, Vasily S

    2010-01-01

    In this review, analytical results obtained for a wide class of stationary axisymmetric flows in the vicinity of compact astrophysical objects are analyzed, with an emphasis on quantitative predictions for specific sources. Recent years have witnessed a great increase in understanding the formation and properties of astrophysical jets. This is due not only to new observations but also to advances in analytical theory which has produced fairly simple relations, and to what can undoubtedly be called a breakthrough in numerical simulation which has enabled confirmation of theoretical predictions. Of course, we are still very far from fully understanding the physical processes occurring in compact sources. Nevertheless, the progress made raises hopes for near-future test observations that can give insight into the physical processes occurring in active astrophysical objects. (reviews of topical problems)

  20. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  1. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1963-01-01

    Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses i

  2. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1962-01-01

    Advances in Astronomy and Astrophysics, Volume 1 brings together numerous research works on different aspects of astronomy and astrophysics. This book is divided into five chapters and begins with an observational summary of the shock-wave theory of novae. The subsequent chapter provides the properties and problems of T tauri stars and related objects. These topics are followed by discussions on the structure and origin of meteorites and cosmic dust, as well as the models for evaluation of mass distribution in oblate stellar systems. The final chapter describes the methods of polarization mea

  3. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1966-01-01

    Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A ch

  4. Advanced LIGO: sources and astrophysics

    International Nuclear Information System (INIS)

    Creighton, Teviet

    2003-01-01

    Second-generation detectors in LIGO will take us from the discovery phase of gravitational-wave observations to the phase of true gravitational-wave astrophysics, with hundreds or thousands of potential sources. This paper surveys the most likely and interesting potential sources for Advanced LIGO, and the astrophysical processes that each one will probe. I conclude that binary inspiral signals are expected, while continuous signals from pulsars are plausible but not guaranteed. Other sources, such as core-collapse bursts, cosmic strings and primordial stochastic backgrounds, are speculative sources for Advanced LIGO, but also potentially the most interesting, since they push the limits of our theoretical knowledge

  5. Nuclear astrophysics away from stability

    International Nuclear Information System (INIS)

    Mathews, G.J.; Howard, W.M.; Takahashi, K.; Ward, R.A.

    1985-08-01

    Explosive astrophysical environments invariably lead to the production of nuclei away from stability. An understanding of the dynamics and nucleosynthesis in such environments is inextricably coupled to an understanding of the properties of the synthesized nuclei. In this talk a review is presented of the basic explosive nucleosynthesis mechanisms (s-process, r-process, n-process, p-process, and rp-process). Specific stellar model calculations are discussed and a summary of the pertinent nuclear data is presented. Possible experiments and nuclear-model calculations are suggested that could facilitate a better understanding of the astrophysical scenarios. 39 refs., 4 figs

  6. White Paper on Nuclear Astrophysics

    OpenAIRE

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; Berstein, Lee A.; Blackmon, Jeffrey C.; Messer, Bronson; Brown, B. Alex; Brown, Edward F.; Brune, Carl R.; Champagne, Art E.; Chieffi, Alessandro; Couture, Aaron J.; Danielewicz, Pawel; Diehl, Roland; El-Eid, Mounib

    2016-01-01

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21-23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town mee...

  7. Nuclear astrophysics lessons from INTEGRAL.

    Science.gov (United States)

    Diehl, Roland

    2013-02-01

    Measurements of high-energy photons from cosmic sources of nuclear radiation through ESA's INTEGRAL mission have advanced our knowledge: new data with high spectral resolution showed that characteristic gamma-ray lines from radioactive decays occur throughout the Galaxy in its interstellar medium. Although the number of detected sources and often the significance of the astrophysical results remain modest, conclusions derived from this unique astronomical window of radiation originating from nuclear processes are important, complementing the widely-employed atomic-line based spectroscopy. We review the results and insights obtained in the past decade from gamma-ray line measurements of cosmic sources in the context of their astrophysical questions.

  8. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1968-01-01

    Advances in Astronomy and Astrophysics, Volume 6 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with the description of improved methods for analyzing and classifying families of periodic orbits in a conservative dynamical system with two degrees of freedom. The next chapter describes the variation of fractional luminosity of distorted components of close binary systems in the course of their revolution, or the accompanying changes in radial velocity. This topic is followed by discussions on vari

  9. Nuclear astrophysics data at ORNL

    International Nuclear Information System (INIS)

    Smith, M.S.; Blackmon, J.C.

    1998-01-01

    There is a new program of evaluation and dissemination of nuclear data of critical importance for nuclear astrophysics within the Physics Division of Oak Ridge National Laboratory. Recent activities include determining the rates of the important 14 O(α,p) 17 F and 17 F(p,γ) 18 Ne reactions, disseminating the Caughlan and Fowler reaction rate compilation on the World Wide Web, and evaluating the 17 O(p,α) 14 N reaction rate. These projects, which are closely coupled to current ORNL nuclear astrophysics research, are briefly discussed along with future plans

  10. Intracluster light at the Frontier - II. The Frontier Fields Clusters

    Science.gov (United States)

    Montes, Mireia; Trujillo, Ignacio

    2018-02-01

    Multiwavelength deep observations are a key tool to understand the origin of the diffuse light in clusters of galaxies: the intracluster light (ICL). For this reason, we take advantage of the Hubble Frontier Fields (HFF) survey to investigate the properties of the stellar populations of the ICL of its six massive intermediate redshift (0.3 1015 M⊙) clusters is formed by the stripping of MW-like objects that have been accreted at z < 1, in agreement with current simulations. We do not find any significant increase in the fraction of light of the ICL with cosmic time, although the redshift range explored is narrow to derive any strong conclusion. When exploring the slope of the stellar mass density profile, we found that the ICL of the HFF clusters follows the shape of their underlying dark matter haloes, in agreement with the idea that the ICL is the result of the stripping of galaxies at recent times.

  11. Journal of Astrophysics and Astronomy

    Indian Academy of Sciences (India)

    27

    Indian Institute of Astrophysics, Koramangala 2nd Block, Bangalore. 560034, India .... the hydrogen rich thermosphere so significantly that the internal energy of the gas becomes greater than the gravitational potential energy. This leads ... way greenhouse, water vapor would reach the stratosphere where it would.

  12. Journal of Astrophysics and Astronomy

    Indian Academy of Sciences (India)

    65

    Northern IMF as simulated by PIC code in parallel with MHD model-Journal of Astrophysics ... The global structure of the collisionless bow shock was inves- tigated by ..... international research community, access to modern space science simulations. ...... LaTeX Font Info: Redeclaring math alphabet \\mathbf on input line 29.

  13. An introduction to nuclear astrophysics

    International Nuclear Information System (INIS)

    Norman, E.B.

    1987-09-01

    The role of nuclear reactions in astrophysics is described. Stellar energy generation and heavy element nucleosynthesis is explained in terms of specific sequences of charged-particle and neutron induced reactions. The evolution and final states of stars are examined. 20 refs. 11 figs., 2 tabs

  14. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  15. Astronomy & Astrophysics: an international journal

    Science.gov (United States)

    Bertout, C.

    2011-07-01

    After a brief historical introduction, we review the scope, editorial process, and production organization of A&A, one of the leading journals worldwide dedicated to publishing the results of astrophysical research. We then briefly discuss the economic model of the Journal and some current issues in scientific publishing.

  16. Compressed Baryonic Matter of Astrophysics

    OpenAIRE

    Guo, Yanjun; Xu, Renxin

    2013-01-01

    Baryonic matter in the core of a massive and evolved star is compressed significantly to form a supra-nuclear object, and compressed baryonic matter (CBM) is then produced after supernova. The state of cold matter at a few nuclear density is pedagogically reviewed, with significant attention paid to a possible quark-cluster state conjectured from an astrophysical point of view.

  17. Electric Currents along Astrophysical Jets

    Directory of Open Access Journals (Sweden)

    Ioannis Contopoulos

    2017-10-01

    Full Text Available Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these fields and their associated electric currents. Several researchers have reported direct evidence for large scale electric currents along astrophysical jets. Quite unexpectedly, their directions are not random as would have been the case if the magnetic field were generated by a magnetohydrodynamic dynamo. Instead, in all kpc-scale detections, the inferred electric currents are found to flow away from the galactic nucleus. This unexpected break of symmetry suggests that a battery mechanism is operating around the central black hole. In the present article, we summarize observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets. We also present recent results of general relativistic radiation magnetohydrodynamic simulations which show the action of the Cosmic Battery in the vicinity of astrophysical black holes.

  18. Indirect methods in nuclear astrophysics

    International Nuclear Information System (INIS)

    Bertulani, C.A.; Shubhchintak; Mukhamedzhanov, A.; Kadyrov, A. S.; Kruppa, A.; Pang, D. Y.

    2016-01-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions. (paper)

  19. Astrophysics on the Lab Bench

    Science.gov (United States)

    Hughes, Stephen W.

    2010-01-01

    In this article some basic laboratory bench experiments are described that are useful for teaching high school students some of the basic principles of stellar astrophysics. For example, in one experiment, students slam a plastic water-filled bottle down onto a bench, ejecting water towards the ceiling, illustrating the physics associated with a…

  20. Nuclear astrophysics: An application of nuclear physics

    International Nuclear Information System (INIS)

    Fueloep, Z.

    2005-01-01

    Nuclear astrophysics, a fruitful combination of nuclear physics and astrophysics can be viewed as a special application of nuclear physics where the study of nuclei and their reactions are motivated by astrophysical problems. Nuclear astrophysics is also a good example for the state of the art interdisciplinary research. The origin of elements studied by geologists is explored by astrophysicists using nuclear reaction rates provided by the nuclear physics community. Due to the high interest in the field two recent Nuclear Physics Divisional Conferences of the European Physical Society were devoted to nuclear astrophysics and a new conference series entitled 'Nuclear Physics in Astrophysics' has been established. Selected problems of nuclear astrophysics will be presented emphasizing the interplay between nuclear physics and astrophysics. As an example the role of 14 N(p,r) 15 O reaction rate in the determination of the age of globular clusters will be discussed in details

  1. International Olympiad on Astronomy and Astrophysics

    Science.gov (United States)

    Soonthornthum, B.; Kunjaya, C.

    2011-01-01

    The International Olympiad on Astronomy and Astrophysics, an annual astronomy and astrophysics competition for high school students, is described. Examples of problems and solutions from the competition are also given. (Contains 3 figures.)

  2. Optimization and industry new frontiers

    CERN Document Server

    Korotkikh, Victor

    2003-01-01

    Optimization from Human Genes to Cutting Edge Technologies The challenges faced by industry today are so complex that they can only be solved through the help and participation of optimization ex­ perts. For example, many industries in e-commerce, finance, medicine, and engineering, face several computational challenges due to the mas­ sive data sets that arise in their applications. Some of the challenges include, extended memory algorithms and data structures, new program­ ming environments, software systems, cryptographic protocols, storage devices, data compression, mathematical and statistical methods for knowledge mining, and information visualization. With advances in computer and information systems technologies, and many interdisci­ plinary efforts, many of the "data avalanche challenges" are beginning to be addressed. Optimization is the most crucial component in these efforts. Nowadays, the main task of optimization is to investigate the cutting edge frontiers of these technologies and systems ...

  3. New frontiers for tomorrow`s world

    Energy Technology Data Exchange (ETDEWEB)

    Kassler, P [Shell International Petroleum Co. Ltd., London (United Kingdom)

    1994-12-31

    The conference paper deals with new frontiers and barricades in the global economic development and their influence on fuel consumption and energy source development. Topics discussed are incremental energy supply - new frontiers, world car population - new frontiers, OPEC crude production capacity vs call on OPEC, incremental world oil demand by region 1992-2000, oil resource cost curve, progress in seismic 1983-1991, Troll picture, cost reduction in renewables, sustained growth scenario, nuclear electricity capacity - France, OECD road transport fuels - barricades, and energy taxation. 18 figs.

  4. Advanced optical instruments technology

    Science.gov (United States)

    Shao, Mike; Chrisp, Michael; Cheng, Li-Jen; Eng, Sverre; Glavich, Thomas; Goad, Larry; Jones, Bill; Kaarat, Philip; Nein, Max; Robinson, William

    1992-08-01

    The science objectives for proposed NASA missions for the next decades push the state of the art in sensitivity and spatial resolution over a wide range of wavelengths, including the x-ray to the submillimeter. While some of the proposed missions are larger and more sensitive versions of familiar concepts, such as the next generation space telescope, others use concepts, common on the Earth, but new to space, such as optical interferometry, in order to provide spatial resolutions impossible with other concepts. However, despite their architecture, the performance of all of the proposed missions depends critically on the back-end instruments that process the collected energy to produce scientifically interesting outputs. The Advanced Optical Instruments Technology panel was chartered with defining technology development plans that would best improve optical instrument performance for future astrophysics missions. At this workshop the optical instrument was defined as the set of optical components that reimage the light from the telescope onto the detectors to provide information about the spatial, spectral, and polarization properties of the light. This definition was used to distinguish the optical instrument technology issues from those associated with the telescope, which were covered by a separate panel. The panel identified several areas for optical component technology development: diffraction gratings; tunable filters; interferometric beam combiners; optical materials; and fiber optics. The panel also determined that stray light suppression instruments, such as coronagraphs and nulling interferometers, were in need of general development to support future astrophysics needs.

  5. An Arbitrary Benchmark CAPM: One Additional Frontier Portfolio is Sufficient

    OpenAIRE

    Ekern, Steinar

    2008-01-01

    First draft: July 16, 2008 This version: October 7, 2008 The benchmark CAPM linearly relates the expected returns on an arbitrary asset, an arbitrary benchmark portfolio, and an arbitrary MV frontier portfolio. The benchmark is not required to be on the frontier and may be non-perfectly correlated with the frontier portfolio. The benchmark CAPM extends and generalizes previous CAPM formulations, including the zero beta, two correlated frontier portfolios, riskless augmented frontier, an...

  6. The Explorer program for astronomy and astrophysics

    International Nuclear Information System (INIS)

    Savage, B.D.; Becklin, E.E.; Cassinelli, J.P.; Dupree, A.K.; Elliot, J.L.; Hoffmann, W.F.; Hudson, H.S.; Jura, M.; Kurfess, J.; Murray, S.S.

    1986-01-01

    This report was prepared to provide NASA with a strategy for proceeding with Explorer-class programs for research in space astronomy and astrophysics. The role of Explorers in astronomy and astrophysics and their past accomplishments are discussed, as are current and future astronomy and astrophysics Explorers. Specific cost needs for an effective Explorer program are considered

  7. The importance of CNO isotopes in astrophysics

    International Nuclear Information System (INIS)

    Audoze, J.

    1977-01-01

    The research into CNO isotopes in astrophysics includes many different subfields of astrophysics such as meteoretical studies, experimental and theoretical nuclear astrophysics, optical astronomy, radio astronomy, etc. The purpose of this paper is to give some overview of the topic and guideline among these different subfields. (G.T.H.)

  8. X-ray polarimetry and new prospects in high-energy astrophysics

    International Nuclear Information System (INIS)

    Sgrò, C.

    2016-01-01

    Polarimetry is universally recognized as one of the new frontiers in X-ray astrophysics. It is a powerful tool to investigate a variety of astrophysical processes, as well as a mean to study fundamental physics in space. A renewed interest is testified by dedicated missions approved for phase A by ESA and NASA. The main advance is the availability of a gas pixel detector that is able to add polarization measurement to imaging and spectroscopy, and can be used at the focus of a conventional X-ray optics. The detector exploits the photoelectric effect in gas and a finely segmented ASIC as a collecting anode. In this work I will describe in detail the experimental technique and the detector concept, and illustrate the scientific prospects of these new missions.

  9. Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

    Science.gov (United States)

    Takabe, Hideaki

    2016-10-01

    This is an article for the memorial lecture of Edward Teller Medal and is presented as memorial lecture at the IFSA03 conference held on September 12th, 2003, at Monterey, CA. The author focuses on his main contributions to fusion science and its extension to astrophysics in the field of theory and computation by picking up five topics. The first one is the anomalous resisitivity to hot electrons penetrating over-dense region through the ion wave turbulence driven by the return current compensating the current flow by the hot electrons. It is concluded that almost the same value of potential as the average kinetic energy of the hot electrons is realized to prevent the penetration of the hot electrons. The second is the ablative stabilization of Rayleigh-Taylor instability at ablation front and its dispersion relation so-called Takabe formula. This formula gave a principal guideline for stable target design. The author has developed an integrated code ILESTA (ID & 2D) for analyses and design of laser produced plasma including implosion dynamics. It is also applied to design high gain targets. The third is the development of the integrated code ILESTA. The forth is on Laboratory Astrophysics with intense lasers. This consists of two parts; one is review on its historical background and the other is on how we relate laser plasma to wide-ranging astrophysics and the purposes for promoting such research. In relation to one purpose, I gave a comment on anomalous transport of relativistic electrons in Fast Ignition laser fusion scheme. Finally, I briefly summarize recent activity in relation to application of the author's experience to the development of an integrated code for studying extreme phenomena in astrophysics.

  10. Frontiers of quantum Monte Carlo workshop: preface

    International Nuclear Information System (INIS)

    Gubernatis, J.E.

    1985-01-01

    The introductory remarks, table of contents, and list of attendees are presented from the proceedings of the conference, Frontiers of Quantum Monte Carlo, which appeared in the Journal of Statistical Physics

  11. Applied thermodynamics: A new frontier for biotechnology

    DEFF Research Database (Denmark)

    Mollerup, Jørgen

    2006-01-01

    The scientific career of one of the most outstanding scientists in molecular thermodynamics, Professor John M. Prausnitz at Berkeley, reflects the change in the agenda of molecular thermodynamics, from hydrocarbon chemistry to biotechnology. To make thermodynamics a frontier for biotechnology...

  12. Frontier search to slow in Indonesia

    International Nuclear Information System (INIS)

    Land, R.

    1992-01-01

    This paper reports that oil and gas exploration in Indonesia likely will begin refocusing on proven areas after 1993, Arthur Andersen and Co.'s Far East oil analyst predicts. Arthur Andersen's James Sales the disappointing exploration results, outdated production sharing contract (PSC) terms, and low oil prices are discouraging companies from exploring frontier acreage. But Indonesian frontier activity during 1992-93 is likely to remain high because a large number of PSCs awarded in the past 2 years by state owned Pertamina cover high risk frontier areas. PSC contractors have disclosed several discoveries on recently awarded frontier tracts. However, the discoveries have been relatively small and far from pipeline infrastructure. With prevailing low oil prices, Pertamina likely will find it difficult to entice companies to extend PSCs or joint operating agreements beyond minimum exploration commitments

  13. Nucleon measurements at the precision frontier

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Carl E. [Physics Department, College of William and Mary, Williamsburg, VA 23187 (United States)

    2013-11-07

    We comment on nucleon measurements at the precision frontier. As examples of what can be learned, we concentrate on three topics, which are parity violating scattering experiments, the proton radius puzzle, and the symbiosis between nuclear and atomic physics.

  14. On the critical frontiers of Potts ferromagnets

    International Nuclear Information System (INIS)

    Magalhaes, A.C.N. de; Tsallis, C.

    1981-01-01

    A conjecture concerning the critical frontiers of q- state Potts ferromagnets on d- dimensional lattices (d > 1) which generalize a recent one stated for planar lattices is formulated. The present conjecture is verified within satisfactory accuracy (exactly in some cases) for all the lattices or arrays whose critical points are known. Its use leads to the prediction of: a) a considerable amount of new approximate critical points (26 on non-planar regular lattices, some others on Husimi trees and cacti); b) approximate critical frontiers for some 3- dimensional lattices; c) the possibly asymptotically exact critical point on regular lattices in the limit d→infinite for all q>=1; d) the possibly exact critical frontier for the pure Potts model on fully anisotropic Bethe lattices; e) the possibly exact critical frontier for the general quenched random-bond Potts ferromagnet (any P(J)) on isotropic Bethe lattices. (Author) [pt

  15. Exploring the Cosmic Frontier, Task A - Direct Detection of Dark Matter, Task B - Experimental Particle Astrophysics

    International Nuclear Information System (INIS)

    Matthews, John A.J.; Gold, Michael S.

    2016-01-01

    This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.

  16. Exploring the Cosmic Frontier, Task A - Direct Detection of Dark Matter, Task B - Experimental Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, John A.J. [Univ. of New Mexico, Albuquerque, NM (United States); Gold, Michael S. [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-11

    This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.

  17. New Frontiers in Passive and Active Nanoantennas

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Ziolkowski, Richard W.

    2017-01-01

    The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers.......The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers....

  18. Frontiers in Time Series and Financial Econometrics

    OpenAIRE

    Ling, S.; McAleer, M.J.; Tong, H.

    2015-01-01

    __Abstract__ Two of the fastest growing frontiers in econometrics and quantitative finance are time series and financial econometrics. Significant theoretical contributions to financial econometrics have been made by experts in statistics, econometrics, mathematics, and time series analysis. The purpose of this special issue of the journal on “Frontiers in Time Series and Financial Econometrics” is to highlight several areas of research by leading academics in which novel methods have contrib...

  19. Focusing Telescopes in Nuclear Astrophysics

    CERN Document Server

    Ballmoos, Peter von

    2007-01-01

    This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

  20. Multifragmentation model for astrophysical strangelets

    International Nuclear Information System (INIS)

    Biswas, Sayan; De, J.N.; Joarder, Partha S.; Raha, Sibaji; Syam, Debapriyo

    2012-01-01

    A model for the possible size distribution of astrophysical strangelets, that fragment out of the warm strange quark matter ejected during the merger of binary strange stars in the Galaxy, is presented here by invoking the statistical multifragmentation model. A simplified assumption of zero quark mass has been considered to obtain such mass-spectrum for the strangelets. An approximate estimate for the intensity of such strangelets in the galactic cosmic rays is also attempted by using a diffusion approximation.

  1. Ongoing Space Physics - Astrophysics Connections

    OpenAIRE

    Eichler, David

    2005-01-01

    I review several ongoing connections between space physics and astrophysics: a) Measurements of energetic particle spectra have confirmed theoretical prediction of the highest energy to which shocks can accelerate particles, and this has direct bearing on the origin of the highest energy cosmic rays. b) Mass ejection in solar flares may help us understand photon ejection in the giant flares of magnetar outbursts. c) Measurements of electron heat fluxes in the solar wind can help us understand...

  2. Estimating the NIH efficient frontier.

    Directory of Open Access Journals (Sweden)

    Dimitrios Bisias

    Full Text Available BACKGROUND: The National Institutes of Health (NIH is among the world's largest investors in biomedical research, with a mandate to: "…lengthen life, and reduce the burdens of illness and disability." Its funding decisions have been criticized as insufficiently focused on disease burden. We hypothesize that modern portfolio theory can create a closer link between basic research and outcome, and offer insight into basic-science related improvements in public health. We propose portfolio theory as a systematic framework for making biomedical funding allocation decisions-one that is directly tied to the risk/reward trade-off of burden-of-disease outcomes. METHODS AND FINDINGS: Using data from 1965 to 2007, we provide estimates of the NIH "efficient frontier", the set of funding allocations across 7 groups of disease-oriented NIH institutes that yield the greatest expected return on investment for a given level of risk, where return on investment is measured by subsequent impact on U.S. years of life lost (YLL. The results suggest that NIH may be actively managing its research risk, given that the volatility of its current allocation is 17% less than that of an equal-allocation portfolio with similar expected returns. The estimated efficient frontier suggests that further improvements in expected return (89% to 119% vs. current or reduction in risk (22% to 35% vs. current are available holding risk or expected return, respectively, constant, and that 28% to 89% greater decrease in average years-of-life-lost per unit risk may be achievable. However, these results also reflect the imprecision of YLL as a measure of disease burden, the noisy statistical link between basic research and YLL, and other known limitations of portfolio theory itself. CONCLUSIONS: Our analysis is intended to serve as a proof-of-concept and starting point for applying quantitative methods to allocating biomedical research funding that are objective, systematic, transparent

  3. Estimating the NIH efficient frontier.

    Science.gov (United States)

    Bisias, Dimitrios; Lo, Andrew W; Watkins, James F

    2012-01-01

    The National Institutes of Health (NIH) is among the world's largest investors in biomedical research, with a mandate to: "…lengthen life, and reduce the burdens of illness and disability." Its funding decisions have been criticized as insufficiently focused on disease burden. We hypothesize that modern portfolio theory can create a closer link between basic research and outcome, and offer insight into basic-science related improvements in public health. We propose portfolio theory as a systematic framework for making biomedical funding allocation decisions-one that is directly tied to the risk/reward trade-off of burden-of-disease outcomes. Using data from 1965 to 2007, we provide estimates of the NIH "efficient frontier", the set of funding allocations across 7 groups of disease-oriented NIH institutes that yield the greatest expected return on investment for a given level of risk, where return on investment is measured by subsequent impact on U.S. years of life lost (YLL). The results suggest that NIH may be actively managing its research risk, given that the volatility of its current allocation is 17% less than that of an equal-allocation portfolio with similar expected returns. The estimated efficient frontier suggests that further improvements in expected return (89% to 119% vs. current) or reduction in risk (22% to 35% vs. current) are available holding risk or expected return, respectively, constant, and that 28% to 89% greater decrease in average years-of-life-lost per unit risk may be achievable. However, these results also reflect the imprecision of YLL as a measure of disease burden, the noisy statistical link between basic research and YLL, and other known limitations of portfolio theory itself. Our analysis is intended to serve as a proof-of-concept and starting point for applying quantitative methods to allocating biomedical research funding that are objective, systematic, transparent, repeatable, and expressly designed to reduce the burden of

  4. High energy astrophysics an introduction

    CERN Document Server

    Courvoisier, Thierry J -L

    2013-01-01

    High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad...

  5. Metaorganisms as the new frontier.

    Science.gov (United States)

    Bosch, Thomas C G; McFall-Ngai, Margaret J

    2011-09-01

    Because it appears that almost all organisms are part of an interdependent metaorganism, an understanding of the underlying host-microbe species associations, and of evolution and molecular underpinnings, has become the new frontier in zoology. The availability of novel high-throughput sequencing methods, together with the conceptual understanding that advances mostly originate at the intersection of traditional disciplinary boundaries, enable biologists to dissect the mechanisms that control the interdependent associations of species. In this review article, we outline some of the issues in inter-species interactions, present two case studies illuminating the necessity of interfacial research when addressing complex and fundamental zoological problems, and show that an interdisciplinary approach that seeks to understand co-evolved multi-species relationships will connect genomes, phenotypes, ecosystems and the evolutionary forces that have shaped them. We hope that this article inspires other collaborations of a similar nature on the diverse landscape commonly referred to as "zoology". Copyright © 2011 Elsevier GmbH. All rights reserved.

  6. Space astronomy and astrophysics program by CSA

    Science.gov (United States)

    Laurin, Denis; Ouellet, Alain; Dupuis, Jean; Chicoine, Ruth-Ann

    2014-07-01

    Canada became actively engaged in space astronomy in the 1990s by contributing two fine guidance sensors to the FUSE Far-UV mission (NASA 1999-2008). In the same period, Canada contributed to ODIN's infrared instrument (ESA 2001-2006) and correlators for VSOP (JAXA 1997-2005). In early 2000, Canada developed its own space telescope, Micro-variability and Observations of STars (MOST), a 15-cm telescope on a microsatellite, operating since 2003, and more recently contributed to the realization of the BRITE nanosatellites constellation. Canada also provided hardware to the European Space Agency's Herschel HIFI instrument and simulators to the SPIRE instrument and data analysis tools for Planck. More recently the Canadian Space Agency (CSA) delivered detector units for the UVIT instrument on board the Indian Space Research Organisation's (ISRO) ASTROSAT. The CSA's most important contribution to a space astronomy mission to date is the Fine Guidance Senor (FGS) and Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument to NASA's James Webb Space Telescope. The CSA is currently building the laser metrology system for JAXA's ASTRO-H hard X-ray telescope. Canadian astronomers contributed to several high profile stratospheric balloon projects investigating the CMB and the CSA recently established a balloon launch facility. As expressed in Canada's new Space Policy Framework announced in February 2014, Canada remains committed to future space exploration endeavors. The policy aims at ensure that Canada is a sought-after partner in the international space exploration missions that serve Canada's national interests; and continuing to invest in the development of Canadian contributions in the form of advanced systems and optical instruments. In the longer term, through consultations and in keeping the Canadian astronomical community's proposed Long Range Plan, the CSA is exploring possibilities to contributions to important missions such as WFIRST, SPICA and Athena

  7. The low-energy frontier of particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-02-15

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  8. BRAVO (Brazilian Astrophysical Virtual Observatory): data mining development

    Science.gov (United States)

    De Carvalho, R. R.; Capelato, H. V.; Velho, H. C.

    2007-08-01

    The primary goal of the BRAVO project is to generate investment in information technology, with particular emphasis on datamining and statistical analysis. From a scientific standpoint, the participants assembled to date are engaged in several scientific projects in various fields of cosmology, astrophysics, and data analysis, with significant contributions from international partners. These scientists conduct research on clusters of galaxies, small groups of galaxies, elliptical galaxies, population synthesis, N-body simulations, and a variety of studies in stellar astrophysics. One of the main aspects of this project is the incorporation of these disparate areas of astrophysical research within the context of the coherent development of database technology.Observational cosmology is one of the branches of science experiencing the largest growth in the past few decades. large photometric and spectroscopic surveys have been carried out in both hemispheres. As a result, an extraordinary amount of data in all portions of the electromagnetic spectrum exists, but without standard techniques for storage and distribution. This project will utilize several specific astronomical databases, created to store data generated by several instruments (including SOAR, Gemini, BDA, etc), uniting them within a common framework and with standard interfaces. We are inviting members of the entire Brazilian astronomical community to partake in this effort. This will certainly impact both education and outreach efforts, as well as the future development of astrophysical research. Finally, this project will provide a constant investment in human resources. First, it will do so by stimulating ongoing short technical visits to Johns Hopkins University and Caltech. These will allow us to bring software technology and expertise in datamining back to Brazil. Second, we will organize the Summer School on Software Technology in Astrophysics, which will be designed to ensure that the Brazilian

  9. Using Visual Analytics to Maintain Situation Awareness in Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Poon, Sarah S.; Aldering, Gregory S.; Thomas, Rollin C.; Quimby, Robert

    2008-07-01

    We present a novel collaborative visual analytics application for cognitively overloaded users in the astrophysics domain. The system was developed for scientists needing to analyze heterogeneous, complex data under time pressure, and then make predictions and time-critical decisions rapidly and correctly under a constant influx of changing data. The Sunfall Data Taking system utilizes severalnovel visualization and analysis techniques to enable a team of geographically distributed domain specialists to effectively and remotely maneuver a custom-built instrument under challenging operational conditions. Sunfall Data Taking has been in use for over eighteen months by a major international astrophysics collaboration (the largest data volume supernova search currently in operation), and has substantially improved the operational efficiency of its users. We describe the system design process by an interdisciplinary team, the system architecture, and the results of an informal usability evaluation of the production system by domain experts in the context of Endsley?s three levels of situation awareness.

  10. MAX: Development of a Laue diffraction lens for nuclear astrophysics

    International Nuclear Information System (INIS)

    Barriere, N.; Ballmoos, P. von; Skinner, G.; Smither, B.; Bastie, P.; Hinglais, E.; Abrosimov, N.; Alvarez, J.M.; Andersen, K.; Courtois, P.; Halloin, H.; Harris, M.; Isern, J.; Jean, P.; Knoedlseder, J.; Ubertini, P.; Vedrenne, G.; Weidenspointner, G.; Wunderer, C.

    2006-01-01

    The next generation of instrumentation for nuclear astrophysics will have to achieve an improvement in sensitivity by a factor of 10-100 over present technologies. With the focusing gamma-ray telescope MAX we take up this challenge and propose to combine the required sensitivity with high spectral and angular resolution, and the capability to measure the polarization of the photons. MAX is a space-borne crystal diffraction telescope, featuring a broad-band Laue lens optimized for the observation of compact sources in two wide energy bands of high astrophysical relevance. Gamma rays will be focused from the large collecting area of a crystal diffraction lens onto a very small detector volume. As a consequence, the signal to background ratio is greatly enhanced, leading to unprecedented sensitivities

  11. Enhancements to the NASA Astrophysics Science Information and Abstract Service

    Science.gov (United States)

    Kurtz, M. J.; Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Murray, S. S.

    1995-05-01

    The NASA Astrophysics Data System Astrophysics Science Information and Abstract Service, the extension of the ADS Abstract Service continues rapidly to expand in both use and capabilities. Each month the service is used by about 4,000 different people, and returns about 1,000,000 pieces of bibliographic information. Among the recent additions to the system are: 1. Whole Text Access. In addition to the ApJ Letters we now have whole text for the ApJ on-line, soon we will have AJ and Rev. Mexicana. Discussions with other publishers are in progress. 2. Space Instrumentation Database. We now provide a second abstract service, covering papers related to space instruments. This is larger than the astronomy and astrophysics database in terms of total abstracts. 3. Reference Books and Historical Journals. We have begun putting the SAO Annals and the HCO Annals on-line. We have put the Handbook of Space Astronomy and Astrophysics by M.V. Zombeck (Cambridge U.P.) on-line. 4. Author Abstracts. We can now include original abstracts in addition to those we get from the NASA STI Abstracts Database. We have included abstracts for A&A in collaboration with the CDS in Strasbourg, and are collaborating with the AAS and the ASP on others. We invite publishers and editors of journals and conference proceedings to include their original abstracts in our service; send inquiries via e-mail to ads@cfa.harvard.edu. 5. Author Notes. We now accept notes and comments from authors of articles in our database. These are arbitrary html files and may contain pointers to other WWW documents, they are listed along with the abstracts, whole text, and data available in the index listing for every reference. The ASIAS is available at: http://adswww.harvard.edu/

  12. Conventional - Frontier and east coast supply

    International Nuclear Information System (INIS)

    Morrell, G.R.

    1998-01-01

    An assessment of frontier basins in Canada with proven potential for petroleum resources was provided. A prediction of which frontier basin will become a major supplier of conventional light oil was made by examining where companies are investing in frontier exploration today. Frontier land values for five active frontier areas were discussed. These included the Grand Banks of Newfoundland, Nova Scotia Offshore, Western Newfoundland, the southern Northwest Territories and the Central Mackenzie Valley. The focus of this presentation was on three of these regions which are actually producing: Newfoundland's Grand Banks, offshore Nova Scotia and the Mackenzie Valley. Activities in each of these areas were reviewed. The Canada-Newfoundland Offshore Petroleum Board has listed Hibernia's reserves at 666 million barrels. The Sable Offshore Energy Project on the continental shelf offshore Nova Scotia proposes to develop 5.4 tcf of gas plus 75 million barrels of NGLs over a project life of 14 years. In the Mackenzie Valley there are at least three petroleum systems, including the 235 million barrel pool at Norman Wells. 8 refs., 1 tab., 3 figs

  13. Dark matter: the astrophysical case

    International Nuclear Information System (INIS)

    Silk, J.

    2012-01-01

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

  14. Nuclear astrophysics with indirect methods

    International Nuclear Information System (INIS)

    Shubhchintak

    2016-01-01

    In the area of astrophysics, it is well known that several different type of nuclear reactions are involved in the production of elements and for energy generation in stars. The knowledge of rates and cross section of these reactions is necessary in order to understand the origin of elements in the universe. Particularly, interests are there in the processes like pp-chain, CNO cycle, r-process and s-process, which are responsible for the formation of majority of the nuclei via various reactions like (p, γ), (n, γ), (α, γ) etc

  15. Nuclear physics in astrophysics. Part 2. Abstracts

    International Nuclear Information System (INIS)

    Gyuerky, Gy.; Fueloep, Zs.

    2005-01-01

    The proceedings of the 20. International Nuclear Physics Divisional Conference of the European Physical Society covers a wide range of topics in nuclear astrophysics. The topics addressed are big bang nucleosynthesis, stellar nucleosynthesis, measurements and nuclear data for astrophysics, nuclear structure far from stability, neutrino physics, and rare-ion-beam facilities and experiments. The perspectives of nuclear physics and astrophysics are also overviewed. 77 items are indexed separately for the INIS database. (K.A.)

  16. High Energy Astrophysics Science Archive Research Center

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Energy Astrophysics Science Archive Research Center (HEASARC) is the primary archive for NASA missions dealing with extremely energetic phenomena, from...

  17. Frontiers, territoriality and tensions in bordering spaces

    Directory of Open Access Journals (Sweden)

    María Eugenia Comerci

    2012-01-01

    Full Text Available The expansión of the agricultural frontier in the Argentine pampas implied a re-valuation of "bordering" spaces, which were considered "marginal" by capital. This paper aims at interpreting the socio-territorial impact -from both a material and a symbolic level- being caused by the expansión of the productive, business-profile [agricultural and oil] frontier in the center-west of the province of La Pampa. With the interpretative approach provided by qualitative methodologies, we intend to analyze -in a case study- how these frontier expansión processes altered and re-defined the social arena between the years 2000 and 2010, the social construction of the space and the power relations in Chos Malal

  18. Contruction of a smoothed DEA frontier

    Directory of Open Access Journals (Sweden)

    Mello João Carlos Correia Baptista Soares de

    2002-01-01

    Full Text Available It is known that the DEA multipliers model does not allow a unique solution for the weights. This is due to the absence of unique derivatives in the extreme-efficient points, which is a consequence of the piecewise linear nature of the frontier. In this paper we propose a method to solve this problem, consisting of changing the original DEA frontier for a new one, smooth (with continuous derivatives at every point and closest to the original frontier. We present the theoretical development for the general case, exemplified with the particular case of the BCC model with one input and one output. The 3-dimensional problem is briefly discussed. Some uses of the model are summarised, and one of them, a new Cross-Evaluation model, is presented.

  19. The Distribution of the Sample Minimum-Variance Frontier

    OpenAIRE

    Raymond Kan; Daniel R. Smith

    2008-01-01

    In this paper, we present a finite sample analysis of the sample minimum-variance frontier under the assumption that the returns are independent and multivariate normally distributed. We show that the sample minimum-variance frontier is a highly biased estimator of the population frontier, and we propose an improved estimator of the population frontier. In addition, we provide the exact distribution of the out-of-sample mean and variance of sample minimum-variance portfolios. This allows us t...

  20. Fundamental Symmetries of the Early Universe and the Precision Frontier

    International Nuclear Information System (INIS)

    Ramsey-Musolf, Michael J.

    2009-01-01

    The search for the next Standard Model of fundamental interactions is being carried out at two frontiers: the high energy frontier involving the Tevatron and Large Hadron Collider, and the high precision frontier where the focus is largely on low energy experiments. I discuss the unique and powerful window on new physics provided by the precision frontier and its complementarity to the information we hope to gain from present and future colliders.

  1. AHP 21: Review: China's Last Imperial Frontier and The Sichuan Frontier and Tibet

    Directory of Open Access Journals (Sweden)

    Robert Entenmann

    2012-12-01

    Full Text Available Until recently, historians have not paid much attention to Qing China's Tibetan frontier, but two excellent new studies address this neglect. One is Yingcong Dai's The Sichuan Frontier and Tibet: Imperial Strategy in the Early Qing, which examines the Qing conquest of the Khams region up to the end of the eighteenth century and its effect on Sichuan. The other is China's Last Imperial Frontier: Late Qing Expansion in Sichuan's Tibetan Borderlands by Xiuyu Wang, in which he describes Qing efforts to impose direct administration on the Khams region in the last years of the dynasty. ...

  2. Strategic Military Colonisation: The Cape Eastern Frontier 1806–1872

    African Journals Online (AJOL)

    The Cape Eastern Frontier of South Africa offers a fascinating insight into British military strategy as well as colonial development. The Eastern Frontier was for over 100 years a very turbulent frontier. It was the area where the four main population groups (the Dutch, the British, the Xhosa and the Khoikhoi) met, and in many ...

  3. The Advanced Telescope for High Energy Astrophysics

    Science.gov (United States)

    Guainazzi, Matteo

    2017-08-01

    Athena (the Advanced Telescope for High Energy Astrophysics) is a next generation X-ray observatory currently under study by ESA for launch in 2028. Athena is designed to address the Hot and Energetic Universe science theme, which addresses two key questions: 1) How did ordinary matter evolve into the large scale structures we see today? 2) How do black holes grow and shape the Universe. To address these topics Athena employs an innovative X-ray telescope based on Silicon Pore Optics technology to deliver extremely light weight and high throughput, while retaining excellent angular resolution. The mirror can be adjusted to focus onto one of two focal place instruments: the X-ray Integral Field Unit (X-IFU) which provides spatially-resolved, high resolution spectroscopy, and the Wide Field Imager (WFI) which provides spectral imaging over a large field of view, as well as high time resolution and count rate tolerance. Athena is currently in Phase A and the study status will be reviewed, along with the scientific motivations behind the mission.

  4. NASA Astrophysics Data System's New Data

    Science.gov (United States)

    Eichhorn, G.; Accomazzi, A.; Demleitner, M.; Grant, C. S.; Kurtz, M. J.; Murray, S. S.

    2000-05-01

    The NASA Astrophysics Data System has greatly increased its data holdings. The Physics database now contains almost 900,000 references and the Astronomy database almost 550,000 references. The Instrumentation database has almost 600,000 references. The scanned articles in the ADS Article Service are increasing in number continuously. Almost 1 million pages have been scanned so far. Recently the abstracts books from the Lunar and Planetary Science Conference have been scanned and put on-line. The Monthly Notices of the Royal Astronomical Society are currently being scanned back to Volume 1. This is the last major journal to be completely scanned and on-line. In cooperation with a conservation project of the Harvard libraries, microfilms of historical observatory literature are currently being scanned. This will provide access to an important part of the historical literature. The ADS can be accessed at: http://adswww.harvard.edu This project is funded by NASA under grant NCC5-189.

  5. Recent astrophysical applications of the Trojan Horse Method to nuclear astrophysics

    International Nuclear Information System (INIS)

    Spitaleri, C.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Tumino, A.; Fu, C.; Tribble, R.; Banu, A.; Al-Abdullah, T.; Goldberg, V.; Mukhamedzhanov, A.; Tabacaru, G.; Trache, L.

    2008-01-01

    The Trojan Horse Method (THM) is an unique indirect technique allowing to measure astrophysical rearrangement reactions down to astrophysical relevant energies. The basic principle and a review of the recent applications of the Trojan Horse Method are presented. The applications aiming to the extraction of the bare astrophysical S b (E) for some two-body processes are discussed

  6. Estimating the NIH Efficient Frontier

    Science.gov (United States)

    2012-01-01

    Background The National Institutes of Health (NIH) is among the world’s largest investors in biomedical research, with a mandate to: “…lengthen life, and reduce the burdens of illness and disability.” Its funding decisions have been criticized as insufficiently focused on disease burden. We hypothesize that modern portfolio theory can create a closer link between basic research and outcome, and offer insight into basic-science related improvements in public health. We propose portfolio theory as a systematic framework for making biomedical funding allocation decisions–one that is directly tied to the risk/reward trade-off of burden-of-disease outcomes. Methods and Findings Using data from 1965 to 2007, we provide estimates of the NIH “efficient frontier”, the set of funding allocations across 7 groups of disease-oriented NIH institutes that yield the greatest expected return on investment for a given level of risk, where return on investment is measured by subsequent impact on U.S. years of life lost (YLL). The results suggest that NIH may be actively managing its research risk, given that the volatility of its current allocation is 17% less than that of an equal-allocation portfolio with similar expected returns. The estimated efficient frontier suggests that further improvements in expected return (89% to 119% vs. current) or reduction in risk (22% to 35% vs. current) are available holding risk or expected return, respectively, constant, and that 28% to 89% greater decrease in average years-of-life-lost per unit risk may be achievable. However, these results also reflect the imprecision of YLL as a measure of disease burden, the noisy statistical link between basic research and YLL, and other known limitations of portfolio theory itself. Conclusions Our analysis is intended to serve as a proof-of-concept and starting point for applying quantitative methods to allocating biomedical research funding that are objective, systematic, transparent

  7. Space astronomy and astrophysics program by NASA

    Science.gov (United States)

    Hertz, Paul L.

    2014-07-01

    The National Aeronautics and Space Administration recently released the NASA Strategic Plan 20141, and the NASA Science Mission Directorate released the NASA 2014 Science Plan3. These strategic documents establish NASA's astrophysics strategic objectives to be (i) to discover how the universe works, (ii) to explore how it began and evolved, and (iii) to search for life on planets around other stars. The multidisciplinary nature of astrophysics makes it imperative to strive for a balanced science and technology portfolio, both in terms of science goals addressed and in missions to address these goals. NASA uses the prioritized recommendations and decision rules of the National Research Council's 2010 decadal survey in astronomy and astrophysics2 to set the priorities for its investments. The NASA Astrophysics Division has laid out its strategy for advancing the priorities of the decadal survey in its Astrophysics 2012 Implementation Plan4. With substantial input from the astrophysics community, the NASA Advisory Council's Astrophysics Subcommittee has developed an astrophysics visionary roadmap, Enduring Quests, Daring Visions5, to examine possible longer-term futures. The successful development of the James Webb Space Telescope leading to a 2018 launch is an Agency priority. One important goal of the Astrophysics Division is to begin a strategic mission, subject to the availability of funds, which follows from the 2010 decadal survey and is launched after the James Webb Space Telescope. NASA is studying a Wide Field Infrared Survey Telescope as its next large astrophysics mission. NASA is also planning to partner with other space agencies on their missions as well as increase the cadence of smaller Principal Investigator led, competitively selected Astrophysics Explorers missions.

  8. TeV Particle Astrophysics 2010, Booklet of abstracts

    International Nuclear Information System (INIS)

    None, C.; Davide Ferella, A.; Pato, M.; Catena, R.; Salucci, P.; Rielage, K.; Kobayashi, K.; Degunda, U.; Estrada, J.; Yue, Q.; Benbow, W.; Maestro, P.; Berghaus, P.; Benzvi, S.; Gallant, Y.; Coniglione, R.; Frey, R.; Besson, D.; Odrowski, S.; Ernenwein, J.P.; Dios Zornosa, J. de; Colnard, C.; Cavalcante de Souza, J.; Fraija, N.; Cerdeno, D.; Moroi, T.; Kumar, J.; Slatyer, T.; Yaguna, C.; Thomson, G.; Tameda, Y.; Taylor, A.; Giacinti, G.; Calvez, A.; Kotera, K.; Shinozaki, K.; Aharonian, F.; Essey, W.; Ahlers, M.; Fargion, D.; Canadas, B.; Boehm, C.; Palomares-Ruiz, S.; Panci, P.; Sanchez-Conde, M.A.; Hensley, B.; Vivier, M.; Hooper, D.; Finkbeiner, D.; Dobler, G.; Malyshev, D.; Mertsch, P.; Giannios, D.; Dalton, M.; Casandijan, J.M.; Mukherjee, R.; Morlino, G.; Ando, S.; Gilmore, R.; Medina, C.; Weitzel, Q.; Caprioli, D.; Vovk, I.; Vincent, S.; Delahaye, T.; Lavalle, J.; Galli, S.; Crocker, R.; Catena, R.; Cholis, I.; Sandick, P.; Rydberg, C.E.; Hulss, J.P.; Danninger, M.; Tran, D.; Spolyar, D.; Belanger, G.; Ronga, F.; Montanino, D.; Fornasa, M.; Regoes, E.; Caprioli, D.; Morlino, G.; Ostapchenko, S.; Kawanaka, N.; Kalli, S.; Whitehorn, N.; Boutayeb, B.; Casanellas, J.; Lopes, I.

    2012-01-01

    The aim of the conference is to bring together theorists and experimentalists working in the fields of Particle Physics, Astrophysics and Cosmology, with a shared interest in physical processes at the TeV energy scale. After decades of theoretical speculation, the exploration of the TeV energy frontier has now in fact begun, with the results provided by ground-based and space-born observatories of gamma-rays (Fermi, HESS, Magic, Veritas, Cangaroo, Milagro), anti-matter (PAMELA, ATIC, HESS and soon AMS-02) and neutrinos (IceCube, Antares), with a large number of ongoing direct Dark Matter search experiments exploiting different detection techniques, and with the TeV particle accelerators Tevatron and the Large Hadron Collider. The physics underlying these experiments involves many intertwined issues, such as the nature of Dark Matter, Physics beyond the Standard Model, the origin of Cosmic Rays and the distribution of Dark and visible matter in the Universe. This document gathers only the abstracts of the papers. (authors)

  9. Plasma phenomenology in astrophysical systems: Radio-sources and jets

    International Nuclear Information System (INIS)

    Montani, Giovanni; Petitta, Jacopo

    2014-01-01

    We review the plasma phenomenology in the astrophysical sources which show appreciable radio emissions, namely Radio-Jets from Pulsars, Microquasars, Quasars, and Radio-Active Galaxies. A description of their basic features is presented, then we discuss in some details the links between their morphology and the mechanisms that lead to the different radio-emissions, investigating especially the role played by the plasma configurations surrounding compact objects (Neutron Stars, Black Holes). For the sake of completeness, we briefly mention observational techniques and detectors, whose structure set them apart from other astrophysical instruments. The fundamental ideas concerning angular momentum transport across plasma accretion disks—together with the disk-source-jet coupling problem—are discussed, by stressing their successes and their shortcomings. An alternative scenario is then inferred, based on a parallelism between astrophysical and laboratory plasma configurations, where small-scale structures can be found. We will focus our attention on the morphology of the radio-jets, on their coupling with the accretion disks and on the possible triggering phenomena, viewed as profiles of plasma instabilities

  10. The Science and Prospects of Astrophysical Observations with New Horizons

    Science.gov (United States)

    Nguyen, Chi; Zemcov, Michael; Cooray, Asantha; Lisse, Carey; Poppe, Andrew

    2018-01-01

    Astrophysical observation from the outer solar system provides a unique and quiet vantage point from which to understand our cosmos. If properly designed, such observations enable several niche science cases that are difficult or impossible to perform near Earth. NASA's New Horizons mission includes several instruments with ~10cm telescopes that provide imaging capability from UV to near-IR wavelengths with moderate spectral resolution. A carefully designed survey can optimize the expendable propellant and limited data telemetry bandwidth to allow several unique measurements, including a detailed understanding of the cosmic extragalactic background light in the optical and near-IR, studies of the local and extragalactic UV background, measurements of the properties of dust and ice in the outer solar system, searches for moons and other faint structures around exoplanets, and determinations of the mass of planets far from their parent stars using gravitational microlensing. New Horizons is currently in an extended mission, that will conclude in 2021, designed to survey distant objects in the Kuiper Belt at high phase angles and perform a close flyby of KBO 2014 MU69. Afterwards, the astrophysics community will have a unique, generational opportunity to use this mission for astronomical observations at heliocentric distances beyond 50 AU. In this poster, we present the science case for an extended 2021 - 2026 astrophysics mission, and discuss some of the practical considerations that must be addressed to maximize the potential science return.

  11. Massive magnetic monopoles in cosmology and astrophysics

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1984-01-01

    The astrophysical and cosmological consequences of magnetic monopoles are discussed. The production of monopoles during phase transition in the early universe is addressed, and proposals which have been made to alleviate the monopole problem are summarized. Astrophysical limits on galactic magnetic monopoles are discussed along with experimental efforts to detect monopoles. Finally, monopole-induced proton decay is addressed. 48 references

  12. Highlights of modern astrophysics: Concepts and controversies

    International Nuclear Information System (INIS)

    Shapiro, S.L.; Teukolsky, V.

    1986-01-01

    In this book, physicists and astronomers review issues in astrophysics. The book stresses accomplishments of observational and theoretical work, and demonstrates how to reveal information about stars and galaxies by applying the basic principles of physics. It pinpoints conflicting views and findings on important topics and indicates possibilities for future research in the field of modern astrophysics

  13. Astrophysics with small satellites in Scandinavia

    DEFF Research Database (Denmark)

    Lund, Niels

    2003-01-01

    The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.......The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved....

  14. Astrophysical targets of the Fresnel diffractive imager

    Science.gov (United States)

    Koechlin, L.; Deba, P.; Raksasataya, T.

    2017-11-01

    The Fresnel Diffractive imager is an innovative concept of distributed space telescope, for high resolution (milli arc-seconds) spectro-imaging in the IR, visible and UV domains. This paper presents its optical principle and the science that can be done on potential astrophysical targets. The novelty lies in the primary optics: a binary Fresnel array, akin to a binary Fresnel zone plate. The main interest of this approach is the relaxed manufacturing and positioning constraints. While having the resolution and imaging capabilities of lens or mirrors of equivalent size, no optical material is involved in the focusing process: just vacuum. A Fresnel array consists of millions void subapertures punched into a large and thin opaque membrane, that focus light by diffraction into a compact and highly contrasted image. The positioning law of the aperture edges drives the image quality and contrast. This optical concept allows larger and lighter apertures than solid state optics, aiming to high angular resolution and high dynamic range imaging, in particular for UV applications. Diffraction focusing implies very long focal distances, up to dozens of kilometers, which requires at least a two-vessel formation flying in space. The first spacecraft, "the Fresnel Array spacecraft", holds the large punched foil: the Fresnel Array. The second, the "Receiver spacecraft" holds the field optics and focal instrumentation. A chromatism correction feature enables moderately large (20%) relative wavebands, and fields of a few to a dozen arc seconds. This Fresnel imager is adapted to high contrast stellar environments: dust disks, close companions and (we hope) exoplanets. Specific to the particular grid-like pattern of the primary focusing zone plate, is the very high dynamic range achieved in the images, in the case of compact objects. Large stellar photospheres may also be mapped with Fresnel arrays of a few meters opertaing in the UV. Larger and more complex fields can be imaged with

  15. Demographics in Astronomy and Astrophysics

    Science.gov (United States)

    Ulvestad, James S.

    2011-05-01

    Astronomy has been undergoing a significant demographic shift over the last several decades, as shown by data presented in the 2000 National Research Council (NRC) report "Federal Funding of Astronomical Research," and the 2010 NRC report, "New Worlds, New Horizons in Astronomy and Astrophysics." For example, the number of advertised postdoctoral positions in astronomy has increased much more rapldly than the number of faculty positions, contributing to a holding pattern of early-career astronomers in multiple postdoctoral positions. This talk will summarize some of the current demographic trends in astronomy, including information about gender and ethnic diversity, and describe some of the possible implications for the future. I thank the members of the Astro2010 Demographics Study Group, as well as numerous white-paper contributors to Astro2010, for providing data and analyses.

  16. Silica aerogel and space astrophysics

    International Nuclear Information System (INIS)

    Koch-Miramond, L.

    1985-09-01

    Silica aerogels have been produced in large and transparent blocks for space astrophysics experiments since the beginning of the 1970's. They were used in cosmic ray experiments on board balloons by the Saclay group. A new space venture where aerogel Cerenkov radiators will play a decisive role is currently being prepared by a large collaboration of European and US Institutes. It will be part of the so-called International Solar Polar Mission (ISPM) which will explore the heliosphere over the full range of solar latitudes from the ecliptic (equatorial) plane to the magnetic poles of the sun. Comments on properties and long term behaviour of silica aerogel cerenkov radiators in space environment are given

  17. Axions in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Sikivie, P.

    1984-07-01

    Axion models often have a spontaneously broken exact discrete symmetry. In that case, they have discretely degenerate vacua and hence domain walls. The properties of the domain walls, the cosmological catastrophe they produce and the ways in which this catastrophe may be avoided are explained. Cosmology and astrophysics provide arguments that imply the axion decay constant should lie in the range 10 8 GeV less than or equal to f/sub a/ less than or equal to 10 12 GeV. Reasons are given why axions are an excellent candidate to constitute the dark matter of galactic halos. Using the coupling of the axions to the electromagnetic field, detectors are described to look for axions floating about in the halo of our galaxy and for axions emitted by the sun

  18. The fundamentals of stellar astrophysics

    International Nuclear Information System (INIS)

    Collins, G.W. II.

    1989-01-01

    A broad overview of theoretical stellar astrophysics is presented in a textbook intended for graduate students. Chapters are devoted to fundamental principles, assumptions, theorems, and polytropes; energy sources and sinks; the flow of energy through the star and the construction of stellar models; the theory of stellar evolution; relativistic stellar structure; the structure of distorted stars; stellar pulsation and oscillation. Also discussed are the flow of radiation through the stellar atmosphere, the solution of the radiative-transfer equation, the environment of the radiation field, the construction of a stellar model atmosphere, the formation and shape of spectral lines, LTE breakdown, illuminated and extended stellar atmospheres, and the transfer of polarized radiation. Diagrams, graphs, and sample problems are provided. 164 refs

  19. Nuclear astrophysics of the sun

    International Nuclear Information System (INIS)

    Kocharov, G.E.

    1980-01-01

    In the first chapter we will discuss the problem of nuclear reactions in the interior of the sun and consider the modern aspects of the neutrino astrophysics of the Sun. The second chapter is devoted to the high energy interactions in the solar atmosphere during the flares. Among a great number of events during the solar flares we shall consider mainly the nuclear reactions. Special attention will be paid to the genetic connection between the different components of solar electromagnetic and corpuscular radiation. The idea of the unity of processes in different parts of the Sun, from hot and dense interior up to the rare plasma of the solar corona will be the main line of the book. (orig./WL) 891 WL/orig.- 892 HIS

  20. Modeling stochastic frontier based on vine copulas

    Science.gov (United States)

    Constantino, Michel; Candido, Osvaldo; Tabak, Benjamin M.; da Costa, Reginaldo Brito

    2017-11-01

    This article models a production function and analyzes the technical efficiency of listed companies in the United States, Germany and England between 2005 and 2012 based on the vine copula approach. Traditional estimates of the stochastic frontier assume that data is multivariate normally distributed and there is no source of asymmetry. The proposed method based on vine copulas allow us to explore different types of asymmetry and multivariate distribution. Using data on product, capital and labor, we measure the relative efficiency of the vine production function and estimate the coefficient used in the stochastic frontier literature for comparison purposes. This production vine copula predicts the value added by firms with given capital and labor in a probabilistic way. It thereby stands in sharp contrast to the production function, where the output of firms is completely deterministic. The results show that, on average, S&P500 companies are more efficient than companies listed in England and Germany, which presented similar average efficiency coefficients. For comparative purposes, the traditional stochastic frontier was estimated and the results showed discrepancies between the coefficients obtained by the application of the two methods, traditional and frontier-vine, opening new paths of non-linear research.

  1. Resources for Teaching about the Frontier.

    Science.gov (United States)

    Seiter, David

    1988-01-01

    Highlights materials relating to the U.S. frontier during the 19th century by citing journal articles and documents related to this topic. Indicates the means for obtaining these works which deal with rural schooling, historical demography, Native Americans, music, revivalism, and Black cowboys. (KO)

  2. THE INVISIBLE FRONTIER: THE CURRENT LIMITS OF ...

    African Journals Online (AJOL)

    tions, area-wide or regional development organizations, specialized functional authorities or ... regional or functional development authorities, parastatal organizations, or special project ..... frontiers between urban, peri-urban and rural activity are blurring and merging. .... KOPP, A., 1998. Networking and rural development.

  3. Risk appetite : reaching for the frontier

    NARCIS (Netherlands)

    dr. A.F. de Wild

    2015-01-01

    Deze poster vat de resultaten samen van een onderzoek in spelvorm gehouden onder 56 Nederlandse risicomanagement professionals. Onderzocht werd of zij in staat waren risico’s optimaal te managen. In het spel konden 10 optimale spelstrategieën gespeeld worden die samen een efficient frontier vormden.

  4. Nonlinear science as a fluctuating research frontier

    International Nuclear Information System (INIS)

    He Jihuan

    2009-01-01

    Nonlinear science has had quite a triumph in all conceivable applications in science and technology, especially in high energy physics and nanotechnology. COBE, which was awarded the physics Nobel Prize in 2006, might be probably more related to nonlinear science than the Big Bang theory. Five categories of nonlinear subjects in research frontier are pointed out.

  5. Large-Scale Astrophysical Visualization on Smartphones

    Science.gov (United States)

    Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

    2011-07-01

    Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

  6. Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions

    OpenAIRE

    Paxton, Bill; Schwab, Josiah; Bauer, Evan B.; Bildsten, Lars; Blinnikov, Sergei; Duffell, Paul; Farmer, R.; Goldberg, Jared A.; Marchant, Pablo; Sorokina, Elena; Thoul, Anne; Townsend, Richard H. D.; Timmes, F. X.

    2017-01-01

    We update the capabilities of the software instrument Modules for Experiments in Stellar Astrophysics (MESA) and enhance its ease of use and availability. Our new approach to locating convective boundaries is consistent with the physics of convection, and yields reliable values of the convective core mass during both hydrogen and helium burning phases. Stars with $M

  7. Frontiere pericolose: l’adattamento Dangerous frontiers: adaptation

    Directory of Open Access Journals (Sweden)

    Sandro Volpe

    2011-04-01

    >good adaptation – must push further, dare in diversity. Departing from a text means setting off, travelling, crossing a frontier to land elsewhere. And sometimes, as Truffaut wished, doing «something different, and better».

  8. Frontier Fields: Engaging Educators, the Youth, and the Public in Exploring the Cosmic Frontier

    Science.gov (United States)

    Lawton, Brandon L.; Eisenhamer, Bonnie; Smith, Denise A.; Summers, Frank; Darnell, John A.; Ryer, Holly

    2015-01-01

    The Frontier Fields is a multi-cycle program of six deep-field observations of strong-lensing galaxy clusters that will be taken in parallel with six deep 'blank fields.' The three-year long collaborative program is led by observations from NASA's Great Observatories. The observations allow astronomers to look deeper into the universe than ever before, and potentially uncover galaxies that are as much as 100 times fainter than what the telescopes can typically observe. The Frontier Fields science program is ideal for informing audiences about scientific advances and topics in STEM. The study of galaxy properties, statistics, optics, and Einstein's theory of general relativity naturally leverages off of the science returns of the Frontier Fields program. As a result, the Space Telescope Science Institute's Office of Public Outreach (OPO) has initiated an education and public outreach (EPO) project to follow the progress of the Frontier Fields.For over two decades, the Hubble EPO program has sought to bring the wonders of the universe to the education community, the youth, and the public, and engage audiences in the adventure of scientific discovery. Program components include standards-based curriculum-support materials, exhibits and exhibit components, professional development workshops, and direct interactions with scientists. We are also leveraging our new social media strategy to bring the science program to the public in the form of an ongoing blog. The main underpinnings of the program's infrastructure are scientist-educator development teams, partnerships, and an embedded program evaluation component. OPO is leveraging this existing infrastructure to bring the Frontier Fields science program to the education community and the public in a cost-effective way.The Frontier Fields program has just completed its first year. This talk will feature the goals and current status of the Frontier Fields EPO program. We will highlight OPO's strategies and infrastructure

  9. Astrophysics at RIA (ARIA) Working Group

    International Nuclear Information System (INIS)

    Smith, Michael S.; Schatz, Hendrik; Timmes, Frank X.; Wiescher, Michael; Greife, Uwe

    2006-01-01

    The Astrophysics at RIA (ARIA) Working Group has been established to develop and promote the nuclear astrophysics research anticipated at the Rare Isotope Accelerator (RIA). RIA is a proposed next-generation nuclear science facility in the U.S. that will enable significant progress in studies of core collapse supernovae, thermonuclear supernovae, X-ray bursts, novae, and other astrophysical sites. Many of the topics addressed by the Working Group are relevant for the RIKEN RI Beam Factory, the planned GSI-Fair facility, and other advanced radioactive beam facilities

  10. Extractive industries and political frontiers in the Amazon during the elastic rubber boom

    International Nuclear Information System (INIS)

    Zarate G, Carlos G

    2008-01-01

    The article analyzes the relationship between the extractive activity of elastic rubber, during the period between the fourth part of 19th century and the first decades of the 20 Th century, in the Amazonian frontier between Brazil, Peru and Colombia, and the process of configuration and definition of the boundaries between these countries. The central aspect of the analysis and the discussion is the questioning of the deterministic and simplistic interpretations that associate, in a mechanical way, the relationship between the kind of rubber species exploited and their production organization, the effects on the indigenous societies, and even the politic organization and delimitation of the bordering territories. It is also expected to show how these interpretations have been wrongly or instrumentally used even in the ideological field, to justify and explain the results of the bordering agreements of these countries, which conduced to establish the current Political frontiers in the Amazon

  11. MUSE integral-field spectroscopy towards the Frontier Fields Cluster Abell S1063

    DEFF Research Database (Denmark)

    Karman, W.; Caputi, K. I.; Grillo, C.

    2015-01-01

    We present the first observations of the Frontier Fields Cluster Abell S1063 taken with the newly commissioned Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph. Because of the relatively large field of view (1 arcmin^2), MUSE is ideal to simultaneously target multiple galaxies...... the cluster, we find 17 galaxies at higher redshift, including three previously unknown Lyman-alpha emitters at z>3, and five multiply-lensed galaxies. We report the detection of a new z=4.113 multiply lensed galaxy, with images that are consistent with lensing model predictions derived for the Frontier...... of scientific topics that can be addressed with a single MUSE pointing. We conclude that MUSE is a very efficient instrument to observe galaxy clusters, enabling their mass modelling, and to perform a blind search for high-redshift galaxies....

  12. Local models of astrophysical discs

    Science.gov (United States)

    Latter, Henrik N.; Papaloizou, John

    2017-12-01

    Local models of gaseous accretion discs have been successfully employed for decades to describe an assortment of small-scale phenomena, from instabilities and turbulence, to dust dynamics and planet formation. For the most part, they have been derived in a physically motivated but essentially ad hoc fashion, with some of the mathematical assumptions never made explicit nor checked for consistency. This approach is susceptible to error, and it is easy to derive local models that support spurious instabilities or fail to conserve key quantities. In this paper we present rigorous derivations, based on an asympototic ordering, and formulate a hierarchy of local models (incompressible, Boussinesq and compressible), making clear which is best suited for a particular flow or phenomenon, while spelling out explicitly the assumptions and approximations of each. We also discuss the merits of the anelastic approximation, emphasizing that anelastic systems struggle to conserve energy unless strong restrictions are imposed on the flow. The problems encountered by the anelastic approximation are exacerbated by the disc's differential rotation, but also attend non-rotating systems such as stellar interiors. We conclude with a defence of local models and their continued utility in astrophysical research.

  13. Mass-23 nuclei in astrophysics

    International Nuclear Information System (INIS)

    Fraser, P R; Amos, K; Van der Kniff, D; Canton, L; Karataglidis, S; Svenne, J P

    2015-01-01

    The formation of mass-23 nuclei by radiative capture is of great interest in astrophysics. A topical problem associated with these isobars is the so-called 22 Na puzzle of ONe white dwarf novae, where the abundance of 22 Na observed is not as is predicted by current stellar models, indicating there is more to learn about how the distribution of elements in the universe occurred. Another concerns unexplained variations in elements abundance on the surface of aging red giant stars. One method for theoretically studying nuclear scattering is the Multi-Channel Algebraic Scattering (MCAS) formalism. Studies to date have used a simple collective-rotor prescription to model the target states which couple to projectile nucleons. While, in general, the target states considered all belong to the ground state rotor band, for some systems it is necessary to include coupling to states outside of this band. Herein we discuss an extension of MCAS to allow coupling of different strengths between such states and the ground state band. This consideration is essential when studying the scattering of neutrons from 22 Ne, a necessary step in studying the mass-23 nuclei mentioned above. (paper)

  14. Frontiers in particle science and technology

    International Nuclear Information System (INIS)

    Goddard, D.T.; Lawson, S.; Williams, R.A.

    2002-07-01

    The study of particulate materials and interfaces is a dominant discipline within chemical, pharmaceutical, biological, mineral, energy, consumer and healthcare products sectors. The role is set to expand with advances in engineered particulates, nanoscience and innovations in materials science and processing. This book addresses some key issues in these new frontiers for the research and industrial community. Such issues will continue to impact the quality of our everyday lives

  15. Efficient Frontier - Comparing Different Volatility Estimators

    OpenAIRE

    Tea Poklepović; Zdravka Aljinović; Mario Matković

    2015-01-01

    Modern Portfolio Theory (MPT) according to Markowitz states that investors form mean-variance efficient portfolios which maximizes their utility. Markowitz proposed the standard deviation as a simple measure for portfolio risk and the lower semi-variance as the only risk measure of interest to rational investors. This paper uses a third volatility estimator based on intraday data and compares three efficient frontiers on the Croatian Stock Market. The results show that ra...

  16. Isometric embeddings in cosmology and astrophysics

    Indian Academy of Sciences (India)

    embedding theory, a given spacetime (or 'brane') is embedded in a higher- ..... If one recalls that the motivation (at least in part) for non-compact extra ... to successfully embed (apparently perfect fluid) astrophysical models, we typically need to.

  17. Transport processes in space physics and astrophysics

    CERN Document Server

    Zank, Gary P

    2014-01-01

    Transport Processes in Space Physics and Astrophysics' is aimed at graduate level students to provide the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. Subjects emphasized in the work include collisional and collisionless processes in gases (neutral or plasma), analogous processes in turbulence fields and radiation fields, and allows for a simplified treatment of the statistical description of the system. A systematic study that addresses the common tools at a graduate level allows students to progress to a point where they can begin their research in a variety of fields within space physics and astrophysics. This book is for graduate students who expect to complete their research in an area of plasma space physics or plasma astrophysics. By providing a broad synthesis in several areas of transport theory and modeling, the work also benefits resear...

  18. X-Ray Calorimeter Arrays for Astrophysics

    Science.gov (United States)

    Kilbourne, Caroline A.

    2009-01-01

    High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. The grating spectrometers on the XMM and Chandra satellites started a new era in x-ray astronomy, but there remains a need for instrumentation that can provide higher spectral resolution with high throughput in the Fe-K band (around 6 keV) and can enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. The instrumentation needed is a broad-band imaging spectrometer - basically an x-ray camera that can distinguish tens of thousands of x-ray colors. The potential benefits to astrophysics of using a low-temperature calorimeter to determine the energy of an incident x-ray photon via measurement of a small change in temperature was first articulated by S. H. Moseley over two decades ago. In the time since, technological progress has been steady, though full realization in an orbiting x-ray telescope is still awaited. A low-temperature calorimeter can be characterized by the type of thermometer it uses, and three types presently dominate the field. The first two types are temperature-sensitive resistors - semiconductors in the metal-insulator transition and superconductors operated in the superconducting-normal transition. The third type uses a paramagnetic thermometer. These types can be considered the three generations of x-ray calorimeters; by now each has demonstrated a resolving power of 2000 at 6 keV, but only a semiconductor calorimeter system has been developed to spaceflight readiness. The Soft X-ray Spectrometer on Astro-H, expected to launch in 2013, will use an array of silicon thermistors with I-IgTe x-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in small arrays, kilo-pixel arrays of the superconducting calorimeters are just now being produced, and it is anticipated that much larger arrays will require the non-dissipative advantage of magnetic thermometers.

  19. The Canadian experience in frontier environmental protection

    International Nuclear Information System (INIS)

    Jones, G.H.

    1991-01-01

    Early Canadian frontier exploration (from 1955 onshore and from 1966 for offshore drilling) caused insignificant public concern. The 1967-1968 Torrey Canyon Tanker and Santa Barbara disasters roused public opinion and governments. In Canada, 1969-1970 Arctic gas blowouts, a tanker disaster, and damage to the 'Manhattan' exacerbated concerns and resulted in new environmental regulatory constraints. From 1970, the Arctic Petroleum Operations Association learned to operate safely with environmental responsibility. It studied physical environment for design criteria, and the biological and human environment to ameliorate impact. APOA's research projects covered sea-ice, permafrost, sea-bottom, oil-spills, bird and mammal migration, fish habitat, food chains, oceanography, meteorology, hunters'/trappers' harvests, etc. In 1971 Eastcoast Petroleum Operators' Association and Alaska Oil and Gas Association followed APOA's cooperative research model. EPOA stressed icebergs and fisheries. Certain research was handled by the Canadian Offshore Oil Spill Research Association. By the mid-1980s these associations had undertaken $70,000,000 of environmental oriented research, with equivalent additional work by member companies on specific needs and similar sums by Federal agencies often working with industry on complementary research. The frontier associations then merged with the Canadian Petroleum Association, already active environmentally in western Canada. Working with government and informing environmental interest groups, the public, natives, and local groups, most Canadian frontier petroleum operations proceeded with minimal delay and environmental disturbance

  20. Nuclear astrophysics and nuclei far from stability

    International Nuclear Information System (INIS)

    Schatz, H.

    2003-01-01

    Unstable nuclei play a critical role in a number of astrophysical scenarios and are important for our understanding of the origin of the elements. Among the most important scenarios are the r-process (Supernovae), Novae, X-ray bursters, and Superbursters. For these astrophysical events I review the open questions, recent developments in astronomy, and how nuclear physics, in particular experiments with radioactive beams, needs to contribute to find the answers. (orig.)

  1. Cosmological and astrophysical neutrino mass measurements

    DEFF Research Database (Denmark)

    Abazajian, K.N.; Calabrese, E.; Cooray, A.

    2011-01-01

    Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach.......Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach....

  2. Technology Development for a Neutrino Astrophysical Observatory

    International Nuclear Information System (INIS)

    Chaloupka, V.; Cole, T.; Crawford, H.J.; He, Y.D.; Jackson, S.; Kleinfelder, S.; Lai, K.W.; Learned, J.; Ling, J.; Liu, D.; Lowder, D.; Moorhead, M.; Morookian, J.M.; Nygren, D.R.; Price, P.B.; Richards, A.; Shapiro, G.; Shen, B.; Smoot, George F.; Stokstad, R.G.; VanDalen, G.; Wilkes, J.; Wright, F.; Young, K.

    1996-01-01

    We propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory

  3. Astrophysics at nTOF facility

    International Nuclear Information System (INIS)

    Tagliente, G.; Colonna, N.; Maronne, S.; Terlizzi, R.; Abondanno, U.; Fujii, K.; Milazzo, P.M.; Moreau, C.; Belloni, F.; Aerts, G.; Berthoumieux, E.; Andriamonje, S.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Alvarez, H.; Duran, I.; Paradela, C.; Alvarez-Velarde, F.; Cano-Ott, D.; Embid-Segura, M.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C.; Gonzalez-Romero, E.; Andrzejewski, J.; Marganiec, J.; Assimakopoulos, P.; Karamanis, D.; Audouin, L.; Dillman, I.; Heil, M.; Kappeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wissak, K.; Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H.; Pigni, M.T.; Baumann, P.; David, S.; Kerveno, M.; Rudolf, G.; Lukic, S.; Becvar, F.; Krticka, M.; Bisterzo, S.; Ferrant, L.; Gallino, R.; Calvino, F.; Poch, A.; Pretel, C.; Calviani, M.; Gramegna, F.; Mastinu, P.; Capote, R.; Mengoni, A.; Capote, R.; Lozano, M.; Quesada, J.; Carrapico, C.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P.; Cennini, P.; Chiaveri, E.; Dahlfors, M.; Kadi, Y.; Sarchiapone, L.; Vlachoudis, V.; Wendler, H.; Chepel, V.; Ferreira-Marques, R.; Goncalves, I.; Lindote, A.; Lopes, I.; Neves, F.; Couture, A.; Cox, J.; O'Brien, S.; Wiescher, M.; Dominga-Pardo, C.; Tain, J.L.; Eleftheriadis, C.; Lamboudis, C.; Savvidis, I.; Stephan, C.; Tassan-Got, L.; Furman, W.; Haas, B.; Haight, R.; Reifarth, R.; Igashira, M.; Koehler, P.; Massimi, C.; Vannini, G.; Papadopoulos, C.; Pavlik, A.; Pavlopoulos, P.; Plomen, A.; Rullhusen, P.; Rauscher, T.; Rubbia, C.; Ventura, A.

    2009-01-01

    The neutron time of flight (n T OF) facility at CERN is a neutron spallation source, its white neutron energy spectrum ranges from thermal to several GeV, covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross-section required in s-process nucleosynthesis. This contribution gives an overview on the astrophysical program made at n T OF facility, the results and the implications will be considered.

  4. Hydrodynamic instabilities in astrophysics and ICF

    International Nuclear Information System (INIS)

    Paul Drake, R.

    2005-01-01

    Inertial fusion systems and astrophysical systems both involve hydrodynamic effects, including sources of pressure, shock waves, rarefactions, and plasma flows. In the evolution of such systems, hydrodynamic instabilities naturally evolve. As a result, a fundamental understanding of hydrodynamic instabilities is necessary to understand their behavior. In addition, high-energy-density facilities designed for ICF purposes can be used to provide and experimental basis for understanding astrophysical processes. In this talk. I will discuss the instabilities that appear in astrophysics and ICF from the common perspective of the basic mechanisms at work. Examples will be taken from experiments aimed at ICF, from astrophysical systems, and from experiments using ICF systems to address issues in astrophysics. The high-energy-density research facilities of today can accelerate small but macroscopic amounts of material to velocities above 100 km/s, can heat such material to temperature above 100 eV, can produce pressures far above a million atmospheres (10''12 dybes/cm''2 or 0.1 TPascal), and can do experiments under these conditions that address basic physics issues. This enables on to devise experiments aimed directly at important process such as the Rayleigh Taylor instability at an ablating surface or at an embedded interface that is accelerating, the Richtmeyer Meshkov evolution of shocked interfaces, and the Kelvin-Helmholtz instability of shear flows. The talk will include examples of such phenomena from the laboratory and from astrophysics, and will discuss experiments to study them. (Author)

  5. Nuclear astrophysics: a new era

    Energy Technology Data Exchange (ETDEWEB)

    Wiescher, Michael; Aprahamian, Ani [Department of Physics, University of Notre Dame (United States); Regan, Paddy [Department of Physics, University of Surrey (United Kingdom)

    2002-02-01

    The latest generation of radioactive-ion-beam facilities promises to shed light on the complex nuclear processes that control the evolution of stars and stellar explosions. The most fundamental question in nature is where do we come from, or, put another way, what are we made of? The late Carl Sagan poetically said that we are all made of stardust, but the origin of the elements has fascinated scientists for thousands of years. Many of the greatest medieval and renaissance scientists dabbled in alchemy, trying to create the elements that make up the cosmos, but we had to wait until the early 20th century to recognize that elements are really defined by the number of protons in the nucleus. According to our current understanding, after the big bang most of the normal or baryonic material in the universe consisted of the lightest two elements, hydrogen and helium, with only trace amounts of lithium and beryllium. All the heavier elements that occur naturally on Earth were created from this original material via a series of nuclear reactions in the cores of stars or in stellar explosions. Over the last decade, ground-based telescopes and satellite-based Observatories have opened new windows on the stars across the electromagnetic spectrum, from infrared to gamma radiation. New technology now makes it possible to observe and analyse short-lived stellar explosions. Indeed, the distribution of elements in 'planetary nebula' and in the ejecta of supernovae and novae give a direct glimpse of individual nucleosynthesis processes. In the February issue of Physics World, Michael Wiescher, Paddy Regan and Ani Aprahamian describe how sate-of-the-art facilities are set to plug many of the gaps in our understanding of nuclear astrophysics. (U.K.)

  6. Distance Measurement Solves Astrophysical Mysteries

    Science.gov (United States)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

  7. The Hubble Frontier Fields: Engaging Multiple Audiences in Exploring the Cosmic Frontier

    Science.gov (United States)

    Lawton, Brandon L.; Smith, Denise A.; Summers, Frank; Ryer, Holly; Slivinski, Carolyn; Lotz, Jennifer M.

    2017-06-01

    The Hubble Frontier Fields is a multi-cycle program of six deep-field observations of strong-lensing galaxy clusters taken in parallel with six deep “blank fields.” The three-year long collaborative program began in late 2013 and is led by observations from NASA’s Great Observatories. The observations, now complete, allow astronomers to look deeper into the universe than ever before, and potentially uncover galaxies that are as much as 100 times fainter than what the telescopes can typically observe. The Frontier Fields science program is ideal for informing audiences about scientific advances and topics in STEM. The study of galaxy properties, statistics, optics, and Einstein’s theory of general relativity naturally leverages off of the science returns of the Frontier Fields program. As a result, the Space Telescope Science Institute’s Office of Public Outreach (OPO) has engaged multiple audiences over the past three years to follow the progress of the Frontier Fields.For over two decades, the STScI outreach program has sought to bring the wonders of the universe to the public and engage audiences in the adventure of scientific discovery. In addition, we are leveraging the reach of the new NASA’s Universe of Learning education program to bring the science of the Frontier Fields to informal education audiences. The main underpinnings of the STScI outreach program and the Universe of Learning education program are scientist-educator development teams, partnerships, and an embedded program evaluation component. OPO is leveraging the infrastructure of these education and outreach programs to bring the Frontier Fields science program to the education community and the public in a cost-effective way.This talk will feature highlights over the past three years of the program. We will highlight OPO’s strategies and infrastructure that allows for the quick delivery of groundbreaking science to the education community and public.

  8. Frontiers in Theoretical and Applied Physics

    CERN Document Server

    2017-01-01

    The aim of the conference is to provide a forum for physicists, astronomers, and space and material scientists from around the world to present the latest developments in the various dynamic fields of physics. Atomic, Molecular and Optical Physics, Condensed Matter Physics, Material Science and Nanophysics, Nuclear and High Energy Physics, Mathematical Physics, Astrophysics, Space and Planetary Physics

  9. A Note on the Kinks at the Mean Variance Frontier

    OpenAIRE

    Vörös, J.; Kriens, J.; Strijbosch, L.W.G.

    1997-01-01

    In this paper the standard portfolio case with short sales restrictions is analyzed.Dybvig pointed out that if there is a kink at a risky portfolio on the efficient frontier, then the securities in this portfolio have equal expected return and the converse of this statement is false.For the existence of kinks at the efficient frontier the sufficient condition is given here and a new procedure is used to derive the efficient frontier, i.e. the characteristics of the mean variance frontier.

  10. The Cherenkov Telescope Array For Very High-Energy Astrophysics

    Science.gov (United States)

    Kaaret, Philip

    2015-08-01

    The field of very high energy (VHE) astrophysics had been revolutionized by the results from ground-based gamma-ray telescopes, including the current imaging atmospheric Cherenkov telescope (IACT) arrays: HESS, MAGIC and VERITAS. A worldwide consortium of scientists from 29 countries has formed to propose the Cherenkov Telescope Array (CTA) that will capitalize on the power of this technique to greatly expand the scientific reach of ground-based gamma-ray telescopes. CTA science will include key topics such as the origin of cosmic rays and cosmic particle acceleration, understanding extreme environments in regions close to neutron stars and black holes, and exploring physics frontiers through, e.g., the search for WIMP dark matter, axion-like particles and Lorentz invariance violation. CTA is envisioned to consist of two large arrays of Cherenkov telescopes, one in the southern hemisphere and one in the north. Each array will contain telescopes of different sizes to provide a balance between cost and array performance over an energy range from below 100 GeV to above 100 TeV. Compared to the existing IACT arrays, CTA will have substantially better angular resolution and energy resolution, will cover a much wider energy range, and will have up to an order of magnitude better sensitivity. CTA will also be operated as an open observatory and high-level CTA data will be placed into the public domain; these aspects will enable broad participation in CTA science from the worldwide scientific community to fully capitalize on CTA's potential. This talk will: 1) review the scientific motivation and capabilities of CTA, 2) provide an overview of the technical design and the status of prototype development, and 3) summarize the current status of the project in terms of its proposed organization and timeline. The plans for access to CTA data and opportunities to propose for CTA observing time will be highlighed.Presented on behalf of the CTA Consortium.

  11. CERN and the high energy frontier

    Directory of Open Access Journals (Sweden)

    Tsesmelis Emmanuel

    2014-04-01

    Full Text Available This paper presents the particle physics programme at CERN at the high-energy frontier. Starting from the key open questions in particle physics and the large-scale science facilities existing at CERN, concentrating on the Large Hadron Collider(LHC, this paper goes on to present future possibilities for global projects in high energy physics. The paper presents options for future colliders, all being within the framework of the recently updated European Strategy for Particle Physics, and all of which have a unique value to add to experimental particle physics. The paper concludes by outlining key messages for the way forward for high-energy physics research.

  12. From "Frontiers of Astronomy" to Astrobiology

    Science.gov (United States)

    Kwok, Sun

    2011-10-01

    In his book Frontiers of Astronomy, Fred Hoyle outlined a number of ideas on the stellar synthesis of solid-state materials and their ejection into the interstellar medium. He also considered the possibility of interstellar organics being integrated into the early Earth during the accretion phase of planetary formation. These organics may have played a role in the origin of life and the creation of fossil fuels. In this paper, we assess these ideas with modern observational evidence, in particular on the evidence of stellar synthesis of complex organics and their delivery to the early Solar System.

  13. Frontiers in biomedical engineering and biotechnology.

    Science.gov (United States)

    Liu, Feng; Goodarzi, Ali; Wang, Haifeng; Stasiak, Joanna; Sun, Jianbo; Zhou, Yu

    2014-01-01

    The 2nd International Conference on Biomedical Engineering and Biotechnology (iCBEB 2013), held in Wuhan on 11–13 October 2013, is an annual conference that aims at providing an opportunity for international and national researchers and practitioners to present the most recent advances and future challenges in the fields of Biomedical Information, Biomedical Engineering and Biotechnology. The papers published by this issue are selected from this conference, which witnesses the frontier in the field of Biomedical Engineering and Biotechnology, which particularly has helped improving the level of clinical diagnosis in medical work.

  14. The Research Frontier in Corporate Governance

    DEFF Research Database (Denmark)

    Ahrens, Thomas; Filatotchev, Igor; Thomsen, Steen

    2011-01-01

    in our knowledge of corporate governance and is likely to lead of a rethink of central concepts like shareholder value, debt governance, and management incentives (2) what do we know and what do we need to how about the impact of national institutions on corporate governance? (3) What research questions......In this paper we attempt to identify the research frontier in corporate governance using three different approaches: (1) what challenges does the financial crisis 2007–2009 pose for corporate governance research? We show that the financial crisis is a huge natural experiment which has exposed gaps...

  15. Energy technology sources, systems and frontier conversion

    CERN Document Server

    Ohta, Tokio

    1994-01-01

    This book provides a concise and technical overview of energy technology: the sources of energy, energy systems and frontier conversion. As well as serving as a basic reference book for professional scientists and students of energy, it is intended for scientists and policy makers in other disciplines (including practising engineers, biologists, physicists, economists and managers in energy related industries) who need an up-to-date and authoritative guide to the field of energy technology.Energy systems and their elemental technologies are introduced and evaluated from the view point

  16. Fermilab a laboratory at the frontier of research

    CERN Document Server

    Gillies, James D

    2002-01-01

    Since its foundation in 1967, creeping urbanization has taken away some of Fermilab's remoteness, but the famous buffalo still roam, and farm buildings evocative of frontier America dot the landscape - appropriately for a laboratory at the high-energy frontier of modern research. Topics discussed are the Tevatron, detector upgrades, the neutrino programme, Fermilab and the LHC and the non-accelerator programme.

  17. A Frontier Model for Landscape Ecology: The Tapir in Honduras

    OpenAIRE

    Kevin Flesher; Eduardo Ley

    1995-01-01

    We borrow a frontier specification from the econometrics literature to make inferences about the tolerance of the tapir to human settlements. We estimate the width of an invisible band surrounding human settlements which would act as a frontier or exclusion zone to the tapir to be around 290 meters.

  18. Efficient Provision of Employment Service Outputs: A Production Frontier Analysis.

    Science.gov (United States)

    Cavin, Edward S.; Stafford, Frank P.

    1985-01-01

    This article develops a production frontier model for the Employment Service and assesses the relative efficiency of the 51 State Employment Security Agencies in attaining program outcomes close to that frontier. This approach stands in contrast to such established practices as comparing programs to their own previous performance. (Author/CT)

  19. On the Endogeneity of the Mean-Variance Efficient Frontier.

    Science.gov (United States)

    Somerville, R. A.; O'Connell, Paul G. J.

    2002-01-01

    Explains that the endogeneity of the efficient frontier in the mean-variance model of portfolio selection is commonly obscured in portfolio selection literature and in widely used textbooks. Demonstrates endogeneity and discusses the impact of parameter changes on the mean-variance efficient frontier and on the beta coefficients of individual…

  20. Plasma Astrophysics, part II Reconnection and Flares

    CERN Document Server

    Somov, Boris V

    2007-01-01

    This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The first part is unique in covering all the basic principles and practical tools required for understanding and working in plasma astrophysics. The second part presents the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas within the solar system; single and double stars, relativistic objects, accretion disks, and their coronae are also covered. This book is designed mainly for professional researchers in astrophysics. However, it will also be interesting and useful to graduate students in space sciences, geophysics, as well as advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.

  1. Plasma Astrophysics, Part I Fundamentals and Practice

    CERN Document Server

    Somov, Boris V

    2006-01-01

    This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The first part is unique in covering all the basic principles and practical tools required for understanding and working in plasma astrophysics. The second part presents the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas within the solar system; single and double stars, relativistic objects, accretion disks, and their coronae are also covered. This book is designed mainly for professional researchers in astrophysics. However, it will also be interesting and useful to graduate students in space sciences, geophysics, as well as advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.

  2. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  3. The Astrophysical Multimessenger Observatory Network (AMON)

    Science.gov (United States)

    Smith. M. W. E.; Fox, D. B.; Cowen, D. F.; Meszaros, P.; Tesic, G.; Fixelle, J.; Bartos, I.; Sommers, P.; Ashtekar, Abhay; Babu, G. Jogesh; hide

    2013-01-01

    We summarize the science opportunity, design elements, current and projected partner observatories, and anticipated science returns of the Astrophysical Multimessenger Observatory Network (AMON). AMON will link multiple current and future high-energy, multimessenger, and follow-up observatories together into a single network, enabling near real-time coincidence searches for multimessenger astrophysical transients and their electromagnetic counterparts. Candidate and high-confidence multimessenger transient events will be identified, characterized, and distributed as AMON alerts within the network and to interested external observers, leading to follow-up observations across the electromagnetic spectrum. In this way, AMON aims to evoke the discovery of multimessenger transients from within observatory subthreshold data streams and facilitate the exploitation of these transients for purposes of astronomy and fundamental physics. As a central hub of global multimessenger science, AMON will also enable cross-collaboration analyses of archival datasets in search of rare or exotic astrophysical phenomena.

  4. Astrophysical observations: lensing and eclipsing Einstein's theories.

    Science.gov (United States)

    Bennett, Charles L

    2005-02-11

    Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.

  5. Astrophysical hints of axion-like particles

    Science.gov (United States)

    Roncadelli, M.; Galanti, G.; Tavecchio, F.; Bonnoli, G.

    2015-01-01

    After reviewing three astrophysical hints of the existence of axion-like particles (ALPs), we describe in more detail a new similar hint involving flat spectrum radio quasars (FSRQs). Detection of FSRQs above about 20GeV pose a challenge to very-high-energy (VHE) astrophysics, because at those energies the ultraviolet emission from their broad line region should prevent photons produced by the central engine to leave the source. Although a few astrophysical explanations have been put forward, they are totally ad hoc. We show that a natural explanation instead arises within the conventional models of FSRQs provided that photon-ALP oscillations occur inside the source. Our analysis takes the FSRQ PKR 1222+206 as an example, and it looks tantalizing that basically the same choice of the free model parameters adopted in this case is consistent with those that provide the other three hints of the existence of ALPs.

  6. The Astrophysics Science Division Annual Report 2008

    Science.gov (United States)

    Oegerle, William; Reddy, Francis; Tyler, Pat

    2009-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. This report includes the Division's activities during 2008.

  7. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Heidbrink, W. W.

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

  8. Exploring New Physics Frontiers Through Numerical Relativity.

    Science.gov (United States)

    Cardoso, Vitor; Gualtieri, Leonardo; Herdeiro, Carlos; Sperhake, Ulrich

    2015-01-01

    The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.

  9. Laboratory Astrophysics Division of The AAS (LAD)

    Science.gov (United States)

    Salama, Farid; Drake, R. P.; Federman, S. R.; Haxton, W. C.; Savin, D. W.

    2012-10-01

    The purpose of the Laboratory Astrophysics Division (LAD) is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. LAD represents all areas of astrophysics and planetary sciences. The first new AAS Division in more than 30 years, the LAD traces its history back to the recommendation from the scientific community via the White Paper from the 2006 NASA-sponsored Laboratory Astrophysics Workshop. This recommendation was endorsed by the Astronomy and Astrophysics Advisory Committee (AAAC), which advises the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the U.S. Department of Energy (DOE) on selected issues within the fields of astronomy and astrophysics that are of mutual interest and concern to the agencies. In January 2007, at the 209th AAS meeting, the AAS Council set up a Steering Committee to formulate Bylaws for a Working Group on Laboratory Astrophysics (WGLA). The AAS Council formally established the WGLA with a five-year mandate in May 2007, at the 210th AAS meeting. From 2008 through 2012, the WGLA annually sponsored Meetings in-a-Meeting at the AAS Summer Meetings. In May 2011, at the 218th AAS meeting, the AAS Council voted to convert the WGLA, at the end of its mandate, into a Division of the AAS and requested draft Bylaws from the Steering Committee. In January 2012, at the 219th AAS Meeting, the AAS Council formally approved the Bylaws and the creation of the LAD. The inaugural gathering and the first business meeting of the LAD were held at the 220th AAS meeting in Anchorage in June 2012. You can learn more about LAD by visiting its website at http://lad.aas.org/ and by subscribing to its mailing list.

  10. Laboratory Astrophysics Division of the AAS (LAD)

    Science.gov (United States)

    Salama, Farid; Drake, R. P.; Federman, S. R.; Haxton, W. C.; Savin, D. W.

    2012-01-01

    The purpose of the Laboratory Astrophysics Division (LAD) is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. LAD represents all areas of astrophysics and planetary sciences. The first new AAS Division in more than 30 years, the LAD traces its history back to the recommendation from the scientific community via the White Paper from the 2006 NASA-sponsored Laboratory Astrophysics Workshop. This recommendation was endorsed by the Astronomy and Astrophysics Advisory Committee (AAAC), which advises the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the U.S. Department of Energy (DOE) on selected issues within the fields of astronomy and astrophysics that are of mutual interest and concern to the agencies. In January 2007, at the 209th AAS meeting, the AAS Council set up a Steering Committee to formulate Bylaws for a Working Group on Laboratory Astrophysics (WGLA). The AAS Council formally established the WGLA with a five-year mandate in May 2007, at the 210th AAS meeting. From 2008 through 2012, the WGLA annually sponsored Meetings in-a-Meeting at the AAS Summer Meetings. In May 2011, at the 218th AAS meeting, the AAS Council voted to convert the WGLA, at the end of its mandate, into a Division of the AAS and requested draft Bylaws from the Steering Committee. In January 2012, at the 219th AAS Meeting, the AAS Council formally approved the Bylaws and the creation of the LAD. The inaugural gathering and the first business meeting of the LAD were held at the 220th AAS meeting in Anchorage in June 2012. You can learn more about LAD by visiting its website at http://lad.aas.org/ and by subscribing to its mailing list.

  11. Radioisotope instruments

    CERN Document Server

    Cameron, J F; Silverleaf, D J

    1971-01-01

    International Series of Monographs in Nuclear Energy, Volume 107: Radioisotope Instruments, Part 1 focuses on the design and applications of instruments based on the radiation released by radioactive substances. The book first offers information on the physical basis of radioisotope instruments; technical and economic advantages of radioisotope instruments; and radiation hazard. The manuscript then discusses commercial radioisotope instruments, including radiation sources and detectors, computing and control units, and measuring heads. The text describes the applications of radioisotop

  12. Byurakan Astrophysical Observatory as Cultural Centre

    Science.gov (United States)

    Mickaelian, A. M.; Farmanyan, S. V.

    2017-07-01

    NAS RA V. Ambartsumian Byurakan Astrophysical Observatory is presented as a cultural centre for Armenia and the Armenian nation in general. Besides being scientific and educational centre, the Observatory is famous for its unique architectural ensemble, rich botanical garden and world of birds, as well as it is one of the most frequently visited sightseeing of Armenia. In recent years, the Observatory has also taken the initiative of the coordination of the Cultural Astronomy in Armenia and in this field, unites the astronomers, historians, archaeologists, ethnographers, culturologists, literary critics, linguists, art historians and other experts. Keywords: Byurakan Astrophysical Observatory, architecture, botanic garden, tourism, Cultural Astronomy.

  13. Theoretical nuclear structure and astrophysics at FAIR

    International Nuclear Information System (INIS)

    Rodríguez, Tomás R

    2014-01-01

    Next generation of radioactive ion beam facilities like FAIR will open a bright future for nuclear structure and nuclear astrophysics research. In particular, very exotic nuclei (mainly neutron rich) isotopes will be produced and a lot of new exciting experimental data will help to test and improve the current nuclear models. In addition, these data (masses, reaction cross sections, beta decay half-lives, etc.) combined with the development of better theoretical approaches will be used as the nuclear physics input for astrophysical simulations. In this presentation I will review some of the state-of-the-art nuclear structure methods and their applications.

  14. Sources and astrophysical effects of gravitational waves

    International Nuclear Information System (INIS)

    Rees, M.J.

    1974-01-01

    The probable sources of short intense gravitational wave emissions are discussed and it is concluded, on the basis of current astrophysical ideas, that the number of events detected by an apparatus such as Weber's would not be more than one pulse par century. Some proposed explanations of a higher event rate are examined briefly but it is suggested that the sensitivity would probably have to be improved by a factor 10 8 if a few events per year due to extragalactic supernovae are to be detectable. The article concludes by mentioning several other kinds of gravitational waves of potential interest in astrophysics

  15. Advances in astronomy and astrophysics 9

    CERN Document Server

    Kopal, Zdenek

    1972-01-01

    Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as

  16. Advances in astronomy and astrophysics 7

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

    Advances in Astronomy and Astrophysics, Volume 7 covers reviews about the advances in astronomy and astrophysics. The book presents reviews on the scattering of electrons by diatomic molecules and on Babcock's theory of the 22-year solar cycle and the latitude drift of the sunspot zone. The text then describes reviews on the structures of the terrestrial planets (Earth, Venus, Mars, Mercury) and on type III solar radio bursts. The compact and dispersed cosmic matter is also considered with regard to the search for new cosmic objects and phenomena and on the nature of the ref shift from compact

  17. Astrophysical relevance of γ transition energies

    International Nuclear Information System (INIS)

    Rauscher, Thomas

    2008-01-01

    The relevant γ energy range is explicitly identified where additional γ strength must be located to have an impact on astrophysically relevant reactions. It is shown that folding the energy dependences of the transmission coefficients and the level density leads to maximal contributions for γ energies of 2≤E γ ≤4 unless quantum selection rules allow isolated states to contribute. Under this condition, electric dipole transitions dominate. These findings allow us to more accurately judge the relevance of modifications of the γ strength for astrophysics

  18. Spherical Panoramas for Astrophysical Data Visualization

    Science.gov (United States)

    Kent, Brian R.

    2017-05-01

    Data immersion has advantages in astrophysical visualization. Complex multi-dimensional data and phase spaces can be explored in a seamless and interactive viewing environment. Putting the user in the data is a first step toward immersive data analysis. We present a technique for creating 360° spherical panoramas with astrophysical data. The three-dimensional software package Blender and the Google Spatial Media module are used together to immerse users in data exploration. Several examples employing these methods exhibit how the technique works using different types of astronomical data.

  19. On the saturation of astrophysical dynamos

    DEFF Research Database (Denmark)

    Dorch, Bertil; Archontis, Vasilis

    2004-01-01

    In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate in the li......In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate...

  20. Bibliometric indicators of young authors in astrophysics

    DEFF Research Database (Denmark)

    Havemann, Frank; Larsen, Birger

    2015-01-01

    We test 16 bibliometric indicators with respect to their validity at the level of the individual researcher by estimating their power to predict later successful researchers. We compare the indicators of a sample of astrophysics researchers who later co-authored highly cited papers before...... their first landmark paper with the distributions of these indicators over a random control group of young authors in astronomy and astrophysics. We find that field and citation-window normalisation substantially improves the predicting power of citation indicators. The sum of citation numbers normalised...

  1. Magnetic processes in astrophysics theory, simulations, experiments

    CERN Document Server

    Rüdiger, Günther; Hollerbach, Rainer

    2013-01-01

    In this work the authors draw upon their expertise in geophysical and astrophysical MHD to explore the motion of electrically conducting fluids, the so-called dynamo effect, and describe the similarities and differences between different magnetized objects. They also explain why magnetic fields are crucial to the formation of the stars, and discuss promising experiments currently being designed to investigate some of the relevant physics in the laboratory. This interdisciplinary approach will appeal to a wide audience in physics, astrophysics and geophysics. This second edition covers such add

  2. High energy astrophysics with ground-based gamma ray detectors

    International Nuclear Information System (INIS)

    Aharonian, F; Buckley, J; Kifune, T; Sinnis, G

    2008-01-01

    Recent advances in ground-based gamma ray astronomy have led to the discovery of more than 70 sources of very high energy (E γ ≥ 100 GeV) gamma rays, falling into a number of source populations including pulsar wind nebulae, shell type supernova remnants, Wolf-Rayet stars, giant molecular clouds, binary systems, the Galactic Center, active galactic nuclei and 'dark' (yet unidentified) galactic objects. We summarize the history of TeV gamma ray astronomy up to the current status of the field including a description of experimental techniques and highlight recent astrophysical results. We also discuss the potential of ground-based gamma ray astronomy for future discoveries and describe possible directions for future instrumental developments

  3. First Session of the Sant Cugat Forum on Astrophysics

    CERN Document Server

    Rea, Nanda; High-Energy Emission from Pulsars and their Systems

    2011-01-01

    The aim of the inaugural meeting of the Sant Cugat Forum on Astrophysics was to address, in a global context, the current understanding of and challenges in high-energy emissions from isolated and non-isolated neutron stars, and to confront the theoretical picture with observations of both the Fermi satellite and the currently operating ground-based Cherenkov telescopes. Participants have also discussed the prospects for possible observations with planned instruments across the multi-wavelength spectrum (e.g. SKA, LOFAR, E-VLT, IXO, CTA) and how they will impact our theoretical understanding of these systems. In keeping with the goals of the Forum, this book not only represents the proceedings of the meeting, but also a reflection on the state-of-the-art in the topic.

  4. Dragonfly: Exploring Titan's Surface with a New Frontiers Relocatable Lander

    Science.gov (United States)

    Barnes, Jason W.; Turtle, Elizabeth P.; Trainer, Melissa G.; Lorenz, Ralph

    2017-10-01

    We proposed to the NASA New Frontiers 4 mission call a lander to assess Titan's prebiotic chemistry, evaluate its habitability, and search for biosignatures on its surface. Titan as an Ocean World is ideal for the study of prebiotic chemical processes and the habitability of an extraterrestrial environment due to its abundant complex carbon-rich chemistry and because both liquid water and liquid hydrocarbons can occur on its surface. Transient liquid water surface environments can be created by both impacts and cryovolcanic processes. In both cases, the water could mix with surface organics to form a primordial soup. The mission would sample both organic sediments and water ice to measure surface composition, achieving surface mobility by using rotors to take off, fly, and land at new sites. The Dragonfly rotorcraft lander can thus convey a single capable instrument suite to multiple locations providing the capability to explore diverse locations 10s to 100s of kilometers apart to characterize the habitability of Titan's environment, investigate how far prebiotic chemistry has progressed, and search for chemical signatures indicative of water- and/or hydrocarbon-based life.

  5. White Paper on Nuclear Astrophysics and Low Energy Nuclear Physics - Part 1. Nuclear Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Arcones, Almudena [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, Jutta E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Others, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-04

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21 - 23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9 - 10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12 - 13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long-standing key questions are well within reach in the coming decade.

  6. Frontiere, confini, limiti: e la geografia?

    Directory of Open Access Journals (Sweden)

    Marcello Tanca

    2011-11-01

    Full Text Available The adjective "geographic" does not draw upon what is conceived and opposed to "cultural" elements, but what is resultant of the meeting and exploration of cultural trajectories - boundaries that men establish and realize to contact with the earth's reality, and their societies therein. The historian Lucien Febvre, Paul Vidal de La Blache's student and friend, wrote "in geography no issue is more important than subdivisions one". At the concept of natural frontiers (that until the 700's, indicated a physical element with greater visibility and stability over and above  any man's work, during the eighteenth century,  the problem of subdivision brought with it complications - ergo,  the identification of a criterion to divide the earth surface in parts. Now since the evidence of each geographical representation is actually the product of a self performative mechanism (Dematteis, this should ensure that we contribute, with all our collective practices, to give a meaning and a symbolic function to physical objects,  frontiers, boundaries and limits. In this respect, individual views lose the often fixed aspect of personal opinion, and the connotation of what is "natural", assumes a different cognitive meaning, along with the political and symbolic points of view that mankind often embraces.

  7. Canada's Dominion Astrophysical Observatory and the rise of 20th Century Astrophysics and Technology

    Science.gov (United States)

    Hesser, James E.; Bohlender, David; Crabtree, Dennis

    2015-08-01

    Construction of Canada’s Dominion Astrophysical Observatory (DAO) commenced in 1914 with first light on 6 May 1918. Its varied, rich contributions to the astronomical heritage of the 20th century continue into the 21st century. The first major research observatory built with public funding on the West Coast of North America, it was Canada’s first ‘big science’ project. DAO welcomed scientists from around the world to use its 1.8m telescope designed by John Stanley Plaskett working in close collaboration with the Warner and Swasey Company of Cleveland, OH. Their original design was copied seven times around the globe, the last occasion being in the 1960s. From Day 1 the DAO welcomed the public for viewing and interaction with the small scientific staff whose early efforts would today be characterized as ‘Key Projects’. Those efforts included measuring the radial velocities of O and B stars that, interpreted through Oort’s ideas of differential rotation, determined the most reliable estimate of the size and mass of the Milky Way available until radio astronomical techniques emerged in the 1950s. The first organic molecule in interstellar space, CH, was discovered by a DAO astronomer. The first, very puzzling estimate of ~3K for the temperature of interstellar space was deduced from interstellar CN observations a year after interstellar CH and CN were discovered. DAO’s heritage of innovative instrumentation continues to the present day where expertise in optically efficient, mechanically stable spectrographs and adaptive optics are much in evidence at Mauna Kea’s CFHT, Gemini and Subaru observatories. In 2009 the DAO was designated a National Historic Site. This presentation will draw links between DAO, developments of Canadian astronomy and the emergence of Mauna Kea as an exceptional global astronomical reserve.

  8. Evolution and seismic tools for stellar astrophysics

    CERN Document Server

    Monteiro, Mario JPFG

    2008-01-01

    A collection of articles published by the journal "Astrophysics and Space Science, Volume 316, Number 1-4", August 2008. This work covers 10 evolution codes and 9 oscillation codes. It is suitable for researchers and research students working on the modeling of stars and on the implementation of seismic test of stellar models.

  9. The Trojan Horse Method in nuclear astrophysics

    International Nuclear Information System (INIS)

    Spitaleri, C.; Cherubini, S.; Del Zoppo, A.; Di Pietrob, A.; Figuerab, P.; Gulino, M.; Lattuadab, M.; Miljanic, Dstroke; Musumarra, A.; Pellegriti, M.G.; Pizzone, R.G.; Rolfs, C.; Romano, S.; Tudisco, S.; Tumino, A.

    2003-01-01

    The basic features of the Trojan Horse Method are discussed together with a review of recent applications, aimed to extract the bare astrophysical S(E)-factor for several two-body processes. In this framework information on electron screening potential U e was obtained from the comparison with direct experiments

  10. Nuclear astrophysics and the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    Spitaleri, C. [University of Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Laboratori Nazionali del Sud - INFN, Catania (Italy); La Cognata, M.; Pizzone, R.G. [Laboratori Nazionali del Sud - INFN, Catania (Italy); Lamia, L. [University of Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Mukhamedzhanov, A.M. [Texas A and M University, Cyclotron Institute, College Station, TX (United States)

    2016-04-15

    In this review, we discuss the new recent results of the Trojan Horse Method that is used to determine reaction rates for nuclear processes in several astrophysical scenarios. The theory behind this technique is shortly presented. This is followed by an overview of some new experiments that have been carried out using this indirect approach. (orig.)

  11. Studying shocks in model astrophysical flows

    International Nuclear Information System (INIS)

    Chakrabarti, S.K.

    1989-01-01

    We briefly discuss some properties of the shocks in the existing models for quasi two-dimensional astrophysical flows. All of these models which allow the study of shock analytically have some unphysical characteristics due to inherent assumptions made. We propose a hybrid model for a thin flow which has fewer unpleasant features and is suitable for the study of shocks. (author). 5 refs

  12. Neutrino Masses and Mixings and Astrophysics

    Science.gov (United States)

    Fuller, George M.

    1998-10-01

    Here we discuss the implications of light neutrino masses and neutrino flavor/type mixing for dark matter, big bang nucleosynthesis, and models of heavy element nucleosynthesis in super novae. We will also argue the other way and discuss possible constraints on neutrino physics from these astrophysical considerations.

  13. Nuclear astrophysics experiments with Pohang neutron facility

    International Nuclear Information System (INIS)

    Kim, Yeong Duk; Yoo, Gwang Ho

    1998-01-01

    Nuclear astrophysics experiments for fundamental understanding of Big Bang nucleosynthesis was performed at Pohang Neutron Facility. Laboratory experiments, inhomogeneous Big Bang nucleosynthesis and S-process were used for nucleosynthesis. For future study, more study on S-process for the desired data and nuclear network calculation are necessary

  14. Astrophysics, cosmology and high energy physics

    International Nuclear Information System (INIS)

    Rees, M.J.

    1983-01-01

    A brief survey is given of some topics in astrophysics and cosmology, with special emphasis on the inter-relation between the properties of the early Universe and recent ideas in high energy physics, and on simple order-of-magnitude arguments showing how the scales and dimensions of cosmic phenomena are related to basic physical constants. (orig.)

  15. Particle physics-astrophysics working group

    International Nuclear Information System (INIS)

    Cronin, J.W.; Kolb, E.W.

    1989-01-01

    The working group met each afternoon and listened to mini-symposia on a broad range of subjects covering all aspects of particle physics---astrophysics both theoretical and experimental. This paper reports that as a result, a number of papers which follow were commissioned to reflect the present status and future prospects of the field

  16. Workshop on gravitational waves and relativistic astrophysics

    Indian Academy of Sciences (India)

    Discussions related to gravitational wave experiments viz. LIGO and LISA as well as to observations of supermassive black holes dominated the workshop sessions on gravitational waves and relativistic astrophysics in the ICGC-2004. A summary of seven papers that were presented in these workshop sessions has been ...

  17. Exotic nuclear beta transitions astrophysical examples

    CERN Document Server

    Takahashi, K

    1981-01-01

    A theoretical study of nuclear beta -transitions under various astrophysical circumstances is reviewed by illustrative examples: 1) continuum-state electron captures in a matter in the nuclear statistical equiplibrium, and ii) bound-state beta -decays in stars in connection with a cosmochronometer and with the s-process branchings. (45 refs).

  18. Challenges and opportunities in laboratory plasma astrophysics

    Science.gov (United States)

    Drake, R. Paul

    2017-06-01

    We are in a period of explosive success and opportunity in the laboratory study of plasma phenomena that are relevant to astrophysics. In this talk I will share with you several areas in which recent work, often foreshadowed 20 or 30 years ago, has produced dramatic initial success with prospects for much more. To begin, the talk will provide a brief look at the types of devices used and the regimes they access, showing how they span many orders of magnitude in parameters of interest. It will then illustrate the types of work one can do with laboratory plasmas that are relevant to astrophysics, which range from direct measurement of material properties to the production of scaled models of certain dynamics to the pursuit of complementary understanding. Examples will be drawn from the flow of energy and momentum in astrophysics, the formation and structure of astrophysical systems, and magnetization and its consequences. I hope to include some discussion of collisionless shocks, very dense plasmas, work relevant to the end of the Dark Ages, reconnection, and dynamos. The talk will conclude by highlighting some topics where it seems that we may be on the verge of exciting new progress.The originators of work discussed, and collaborators and funding sources when appropriate, will be included in the talk.

  19. Statistics and Informatics in Space Astrophysics

    Science.gov (United States)

    Feigelson, E.

    2017-12-01

    The interest in statistical and computational methodology has seen rapid growth in space-based astrophysics, parallel to the growth seen in Earth remote sensing. There is widespread agreement that scientific interpretation of the cosmic microwave background, discovery of exoplanets, and classifying multiwavelength surveys is too complex to be accomplished with traditional techniques. NASA operates several well-functioning Science Archive Research Centers providing 0.5 PBy datasets to the research community. These databases are integrated with full-text journal articles in the NASA Astrophysics Data System (200K pageviews/day). Data products use interoperable formats and protocols established by the International Virtual Observatory Alliance. NASA supercomputers also support complex astrophysical models of systems such as accretion disks and planet formation. Academic researcher interest in methodology has significantly grown in areas such as Bayesian inference and machine learning, and statistical research is underway to treat problems such as irregularly spaced time series and astrophysical model uncertainties. Several scholarly societies have created interest groups in astrostatistics and astroinformatics. Improvements are needed on several fronts. Community education in advanced methodology is not sufficiently rapid to meet the research needs. Statistical procedures within NASA science analysis software are sometimes not optimal, and pipeline development may not use modern software engineering techniques. NASA offers few grant opportunities supporting research in astroinformatics and astrostatistics.

  20. Balance in the NASA Astrophysics Program

    Science.gov (United States)

    Elvis, Martin

    2017-08-01

    The Decadal studies are usually instructed to come up with a “balanced program” for the coming decade of astrophysics initiatives, both on the ground and in space. The meaning of “balance” is left up to the Decadal panels. One meaning is that there should be a diversity of mission costs in the portfolio. Another that there should be a diversity of science questions addressed. A third is that there should be a diversity of signals (across electromagnetic wavebands, and of non-em carriers). It is timely for the astronomy community to debate the meaning of balance in the NASA astrophysics program as the “Statement of Task” (SoT) that defines the goals and process of the 2020 Astrophysics Decadal review are now being formulated.Here I propose some ways in which the Astro2020 SoT could be made more specific in order to make balance more evident and so avoid the tendency for a single science question, and a single mission to answer that question, to dominate the program. As an example of an alternative ambitious approach, I present a proof-of-principle program of 6, mostly “probe-class” missions, that would fit the nominal funding profile for the 2025-2035 NASA Astrophysics Program, while being more diverse in ambitious science goals and in wavelength coverage.

  1. Microphysics, cosmology, and high energy astrophysics

    International Nuclear Information System (INIS)

    Hoyle, F.

    1974-01-01

    The discussion of microphysics, cosmology, and high energy astrophysics includes particle motion in an electromagnetic field, conformal transformations, conformally invariant theory of gravitation, particle orbits, Friedman models with k = 0, +-1, the history and present status of steady-state cosmology, and the nature of mass. (U.S.)

  2. Pulsars as tools for fundamental physics & astrophysics

    NARCIS (Netherlands)

    Cordes, J.M.; Kramer, M.; Lazio, T.J.W.; Stappers, B.W.; Backer, D.C.; Johnston, S.

    2004-01-01

    The sheer number of pulsars discovered by the SKA, in combination with the exceptional timing precision it can provide, will revolutionize the field of pulsar astrophysics. The SKA will provide a complete census of pulsars in both the Galaxy and in Galactic globular clusters that can be used to

  3. Cosmological grand unification monopoles: astrophysical constraints

    International Nuclear Information System (INIS)

    Fry, J.N.

    1982-01-01

    I review the general arguments which suggest that relic GU magnetic monopoles should emerge from the early universe, and I discuss several astrophysical settings in which their effects could be, but are not, observed. This places limits on their possible flux, and their abundance bound to more ordinary material

  4. Astrophysical contributions of the International Ultraviolet Explorer

    International Nuclear Information System (INIS)

    Kondo, Y.; Boggess, A.; Maran, S.P.

    1989-01-01

    Findings that have been made by the IUE in a variety of astrophysical areas are reviewed. Results on stellar chromospheres and transition regions, evolutionary processes in interacting binaries, winds from early-type stars, the ISM, SN 1987A, active galactic nuclei, and solar system objects are addressed. 158 refs

  5. Minicourses in Astrophysics, Modular Approach, Vol. II.

    Science.gov (United States)

    Illinois Univ., Chicago.

    This is the second of a two-volume minicourse in astrophysics. It contains chapters on the following topics: stellar nuclear energy sources and nucleosynthesis; stellar evolution; stellar structure and its determination; and pulsars. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are…

  6. Teaching Astrophysics to Upper Level Undergraduates

    Science.gov (United States)

    Van Dorn Bradt, Hale

    2010-03-01

    A Socratic peer-instruction method for teaching upper level undergraduates is presented. Basically, the instructor sits with the students and guides their presentations of the material. My two textbooks* (on display) as well as many others are amenable to this type of teaching. *Astronomy Methods - A Physical Approach to Astronomical Observations (CUP 2004) *Astrophysics Processes-The Physics of Astronomical Phenomena (CUP 2008)

  7. Astronomy and astrophysics in the new millennium: Panel reports

    National Research Council Canada - National Science Library

    Astronomy and Astrophysics Survey Committee, Board on Physics and Astronomy, Space Studies Board, National Research Council

    2001-01-01

    In preparing the report, Astronomy and Astrophysics in the New Millenium , the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysic...

  8. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Since 1977, papers in Astrophysics and Astronomy appeared as a special section in Pramana. ... The journal publishes original research papers on all aspects of astrophysics and ... Articles are also visible in Web of Science immediately.

  9. NASA Astrophysics Cosmic Origins (COR) and Physics of the Cosmos (PCOS) Strategic Technology Development Program

    Science.gov (United States)

    Pham, Thai; Seery, Bernard D.

    2015-01-01

    The COR and PCOS Program Offices (PO) reside at the NASA Goddard Space Flight Center (GSFC), serving as the NASA Astrophysics Division's implementation arm for matters relating to the two programs. One aspect of the PO's activities is managing the COR and PCOS Strategic Astrophysics Technology (SAT) program, helping mature technologies to enable and enhance future astrophysics missions.The PO is guided by the National Research Council's 'New Worlds, New Horizons in Astronomy and Astrophysics' Decadal Survey report, and NASA's Astrophysics Implementation Plan. Strategic goals include dark energy; gravitational waves; X-ray observatories, e.g., US participation in ATHENA; Inflation probe; and a large UV/Visible telescope.To date, 51 COR and 65 PCOS SAT proposals have been received, of which 11 COR and 18 PCOS projects were funded. Notable successes include maturation of a new far-IR detector, later adopted by the SOFIA HAWC instrument; maturation of the H4RG near-IR detector, adopted by WFIRST; development of an antenna-coupled transition-edge superconducting bolometer, a technology deployed by BICEP2 that allowed measurement of B-mode polarization in the CMB signal, a possible signature of Inflation; and finally, the REXIS instrument on OSIRIS-REx is incorporating CCDs with directly deposited optical blocking filters developed by another SAT-funded project.We discuss our technology development process, with community input and strategic prioritization informing calls for SAT proposals and guiding investment decisions. We also present results of this year's technology gap prioritization and showcase our current portfolio of technology development projects. These include five newly selected projects, kicking off in FY 2015.For more information, visit the COR Program website at cor.gsfc.nasa.gov and the PCOS website at pcos.gsfc.nasa.gov.

  10. [Brazilian colonization in the Paraguayan agricultural frontier].

    Science.gov (United States)

    Neupert, R F

    1991-04-01

    This work briefly describes Brazilian colonization of the Paraguayan agricultural frontier, analyzes factors responsible for expelling population from Brazil and for attracting Brazilians to Paraguay, and assesses the economic and social consequences of immigration to the area. Paraguay's vast and sparsely populated agricultural frontier in areas outside the Central subregion underwent a process of intense colonization from the early 1960s to the mid-1980s. The Paraguayan government initiated an ambitious colonization program in 1963 to increase production, relieve population pressure and subdivision of small parcels in the Central subregion, encourage agricultural modernization, and produce a more diversified agriculture. Paraguayan agriculture in the early 1960s suffered from excessive concentration of land in a few hands and resulting exclusion of around 3/4 of workers from ownership and from any possibility of obtaining credit to fund technological improvements. Results of studies 2 decades after implementation of the colonization plan suggest that it has failed in significant areas. Although a considerable population redistribution alleviated pressure in the Central subregion, it apparently resulted more from spontaneous movement of peasants outside the colonization areas than from the official program. Concentration of lands is now occurring in the colonization area. Assistance for agricultural modernization and diversification of production in the peasant sector has been minimal. On the other hand, production of soy, wheat, and cotton for export increased substantially, because of an entrepreneurial agriculture capitalized by foreign as well as national interests The unmet goals of the colonization program would have required structural reforms rather than simple spatial redistribution of the population. Many of the colonists in the 1970s were Brazilian families displaced by mechanized agriculture in the southern states of Parana, Santa Catarina, and Rio

  11. Frontier lands: Oil and gas statistical overview, 1992

    International Nuclear Information System (INIS)

    1993-01-01

    Canada's frontier lands consist of offshore and onshore areas outside the provinces which fall under federal authority. These lands cover some 10.2 million km 2 and include the Northwest Territories, Yukon Territory, and areas off the east and west coasts and in the far north. A statistical summary is presented of oil and gas activities in these frontier lands for 1992. Information provided includes activity status and wells drilled on frontier lands, a resource inventory, oil and gas production, land holdings and status, licenses concluded, petroleum-related employment on frontier lands, and petroleum expenditures on frontier lands. Highlights of activities include the first commercial production of crude oil from the Panuke oil field on the Scotian Shelf; a continued decrease in exploration activity on the frontier lands; the introduction of legislation to eliminate restrictions on foreign ownership of production licences on frontier lands; and the resolution to the Canada-France maritime boundary dispute by the International Court of Arbitration. 9 figs., 10 tabs

  12. Study of aluminum emission spectra in astrophysical plasmas

    International Nuclear Information System (INIS)

    Jin Zhan; Zhang Jie

    2001-01-01

    High temperature, high density and strong magnetic fields in plasmas produced by ultra-high intensity and ultrashort laser pulses are similar to the main characteristics of astrophysical plasmas. This makes it possible to simulate come astrophysical processes at laboratories. The author presents the theoretic simulation of aluminum emission spectra in astrophysical plasmas. It can be concluded that using laser produced plasmas, the authors can obtain rich information on astrophysical spectroscopy, which is unobservable for astronomer

  13. Instrumental interaction

    OpenAIRE

    Luciani , Annie

    2007-01-01

    International audience; The expression instrumental interaction as been introduced by Claude Cadoz to identify a human-object interaction during which a human manipulates a physical object - an instrument - in order to perform a manual task. Classical examples of instrumental interaction are all the professional manual tasks: playing violin, cutting fabrics by hand, moulding a paste, etc.... Instrumental interaction differs from other types of interaction (called symbolic or iconic interactio...

  14. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Anjan A. Sen. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 33 Review. Cosmology and Astrophysics using the Post-Reionization HI · Tapomoy Guha Sarkar Anjan A. Sen · More Details Abstract Fulltext PDF.

  15. 3rd Session of the Sant Cugat Forum on Astrophysics

    CERN Document Server

    Gravitational wave astrophysics

    2015-01-01

    This book offers review chapters written by invited speakers of the 3rd Session of the Sant Cugat Forum on Astrophysics — Gravitational Waves Astrophysics. All chapters have been peer reviewed. The book goes beyond normal conference proceedings in that it provides a wide panorama of the astrophysics of gravitational waves and serves as a reference work for researchers in the field.

  16. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Indian Institute of Astrophysics, Koramangala, Bangalore 560 034, India. Kavli Institute for Astronomy & Astrophysics, Peking University, Beijing 100871, China. National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia, Canada. Thirty Meter Project Office, ...

  17. ASTROPHYSICS: The oldest galaxy yet

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Full text: The most remote galaxy ever seen directly has been detected by astronomers using the ESO (European Southern Observatory's) 3.5 metre New Technology Telescope (NTT) at La Silla, Chile, and the 10-metre Keck telescope in Hawaii. It shows that stellar evolution was already well underway some 10 billion years ago, when the Universe was 'only' a few billion years old. Due to the continual expansion of the Universe in the wake of the Big Bang, visible light emitted a long time ago becomes 'stretched', and appears redder. This 'redshift' is a measure of how long ago the radiation was emitted. Until this new sighting, the oldest known objects were quasars, huge concentrations of matter at the fringe of the Universe blasting energy out into space. Looking hard at such a quasar, ESO astronomers noticed that light of one particular wavelength was strongly absorbed, indicating an intervening cloud of hydrogen. (In intergalactic space, such absorption spectra are not seen - September, page 34.) The redshift of the absorption line showed that the cloud itself was almost (90%) as old as the Universe. Further study revealed other absorption lines, showing that the cloud also contained carbon, oxygen, aluminium and sulphur. So much indirect evidence for stellar-like material suggested that stars might be around. Earlier this year the ESO astronomers embarked on a search for directly visible material. Their CCD SUSI (SUperb Seeing Instrument) picked up a faint signal just 2 arcsec away from the quasar. This tiny angular separation corresponds to a distance 'on the ground' of 40,000 light-years. There are strong indications that this galaxy contains all the necessary nuclei to produce the observed absorption effects. Only hydrogen and helium were produced in the Big Bang, heavier nuclei having been 'cooked' by thermonuclear reactions inside stars. The newly-observed galaxy is the oldest visible source yet of heavier

  18. Frontiers of interfacial water research :workshop report.

    Energy Technology Data Exchange (ETDEWEB)

    Cygan, Randall Timothy; Greathouse, Jeffery A.

    2005-10-01

    Water is the critical natural resource of the new century. Significant improvements in traditional water treatment processes require novel approaches based on a fundamental understanding of nanoscale and atomic interactions at interfaces between aqueous solution and materials. To better understand these critical issues and to promote an open dialog among leading international experts in water-related specialties, Sandia National Laboratories sponsored a workshop on April 24-26, 2005 in Santa Fe, New Mexico. The ''Frontiers of Interfacial Water Research Workshop'' provided attendees with a critical review of water technologies and emphasized the new advances in surface and interfacial microscopy, spectroscopy, diffraction, and computer simulation needed for the development of new materials for water treatment.

  19. Mapping frontier research in the humanities

    DEFF Research Database (Denmark)

    -academic fields and supplemented by new transdisciplinary methods focusing on solving grand societal challenges, such as globalisation, multiculturalism, equality, democracy, security and health. Given the nature of these challenges and the ways in which university leadership has been organised, the very notion...... of impact and styles of reasoning, both in classical and interdisciplinary fields of the humanities. From this perspective, a more composite picture of human culture, language and history can emerge from humanities research. It goes beyond the picture of rational agents, and situates human interaction...... in more complex landscapes of collective identities, networks, and constraints that open for new forms of intellectual leadership in the 21st century. Link: http://www.bloomsbury.com/uk/mapping-frontier-research-in-the-humanities-9781472597687/...

  20. Mapping Frontier Research in the Humanities

    DEFF Research Database (Denmark)

    -academic fields and supplemented by new transdisciplinary methods focusing on solving grand societal challenges, such as globalisation, multiculturalism, equality, democracy, security and health. Given the nature of these challenges and the ways in which university leadership has been organised, the very notion...... of impact and styles of reasoning, both in classical and interdisciplinary fields of the humanities. From this perspective, a more composite picture of human culture, language and history can emerge from humanities research. It goes beyond the picture of rational agents, and situates human interaction...... in more complex landscapes of collective identities, networks, and constraints that open for new forms of intellectual leadership in the 21st century. Link: http://www.bloomsbury.com/uk/mapping-frontier-research-in-the-humanities-9781472597687/...

  1. Frontiers in Optimization : Theory and Applications

    CERN Document Server

    Maulik, Ujjwal; Li, Xiang; FOTA 2016; Operations Research and Optimization

    2018-01-01

    This book discusses recent developments in the vast domain of optimization. Featuring papers presented at the 1st International Conference on Frontiers in Optimization: Theory and Applications (FOTA 2016), held at the Heritage Institute of Technology, Kolkata, on 24–26 December 2016, it opens new avenues of research in all topics related to optimization, such as linear and nonlinear optimization; combinatorial-, stochastic-, dynamic-, fuzzy-, and uncertain optimization; optimal control theory; as well as multi-objective, evolutionary and convex optimization and their applications in intelligent information and technology, systems science, knowledge management, information and communication, supply chain and inventory control, scheduling, networks, transportation and logistics and finance. The book is a valuable resource for researchers, scientists and engineers from both academia and industry.

  2. Microfluidics expanding the frontiers of microbial ecology.

    Science.gov (United States)

    Rusconi, Roberto; Garren, Melissa; Stocker, Roman

    2014-01-01

    Microfluidics has significantly contributed to the expansion of the frontiers of microbial ecology over the past decade by allowing researchers to observe the behaviors of microbes in highly controlled microenvironments, across scales from a single cell to mixed communities. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. In this article, we review applications of microfluidics that have resulted in insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control microbial processes such as biofilm formation and antibiotic resistance.

  3. Materials Frontiers to Empower Quantum Computing

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Antoinette Jane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sarrao, John Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Richardson, Christopher [Laboratory for Physical Sciences, College Park, MD (United States)

    2015-06-11

    This is an exciting time at the nexus of quantum computing and materials research. The materials frontiers described in this report represent a significant advance in electronic materials and our understanding of the interactions between the local material and a manufactured quantum state. Simultaneously, directed efforts to solve materials issues related to quantum computing provide an opportunity to control and probe the fundamental arrangement of matter that will impact all electronic materials. An opportunity exists to extend our understanding of materials functionality from electronic-grade to quantum-grade by achieving a predictive understanding of noise and decoherence in qubits and their origins in materials defects and environmental coupling. Realizing this vision systematically and predictively will be transformative for quantum computing and will represent a qualitative step forward in materials prediction and control.

  4. Biomedical engineering frontier research and converging technologies

    CERN Document Server

    Jun, Ho-Wook; Shin, Jennifer; Lee, SangHoon

    2016-01-01

    This book provides readers with an integrative overview of the latest research and developments in the broad field of biomedical engineering. Each of the chapters offers a timely review written by leading biomedical engineers and aims at showing how the convergence of scientific and engineering fields with medicine has created a new basis for practically solving problems concerning human health, wellbeing and disease. While some of the latest frontiers of biomedicine, such as neuroscience and regenerative medicine, are becoming increasingly dependent on new ideas and tools from other disciplines, the paradigm shift caused by technological innovations in the fields of information science, nanotechnology, and robotics is opening new opportunities in healthcare, besides dramatically changing the ways we actually practice science. At the same time, a new generation of engineers, fluent in many different scientific “languages,” is creating entirely new fields of research that approach the “old” questions f...

  5. Africa: the new family planning frontier.

    Science.gov (United States)

    Caldwell, John C; Caldwell, Pat

    2002-03-01

    Sub-Saharan Africa will be the family planning frontier of the twenty-first century. Fertility levels and population growth rates are still high, and family planning programs suited to the region are still being developed. Nevertheless, by the end of the twentieth century, fertility transition was under way in Southern Africa and a few countries elsewhere. Successful regional family planning in the twenty-first century will depend upon stronger political leadership, the development of family planning programs that meet the needs of all segments of society and not only currently married women, assistance to the market, and a recognition of the central importance of hormonal methods, especially injectables. Problems include stagnation in economic growth and in child mortality decline, as well as the persistence of the AIDS epidemic.

  6. Frontiers of biomedical text mining: current progress

    Science.gov (United States)

    Zweigenbaum, Pierre; Demner-Fushman, Dina; Yu, Hong; Cohen, Kevin B.

    2008-01-01

    It is now almost 15 years since the publication of the first paper on text mining in the genomics domain, and decades since the first paper on text mining in the medical domain. Enormous progress has been made in the areas of information retrieval, evaluation methodologies and resource construction. Some problems, such as abbreviation-handling, can essentially be considered solved problems, and others, such as identification of gene mentions in text, seem likely to be solved soon. However, a number of problems at the frontiers of biomedical text mining continue to present interesting challenges and opportunities for great improvements and interesting research. In this article we review the current state of the art in biomedical text mining or ‘BioNLP’ in general, focusing primarily on papers published within the past year. PMID:17977867

  7. Geneva University: New frontiers on photodetection

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Vendredi 17 février 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 14h00 - Auditoire Stückelberg New frontiers on photodetection Dr Carla Aramo / INFN, Sezione di Napoli In the last years the use of new materials and new technologies opened the door to new kind of devices based on the coupling of well known properties of silicon with properties of other materials. In particular carbon material, in the form of carbon nanotubes, has been used to create heterojunction with interesting photoconductivity characteristics. The new photodetectors obtained show to have peculiar and interesting characteristics with quantum efficiency ranging from >35% to >15% in the investigated wavelength interval from near infrared to near ultraviolet region. The device character...

  8. Experimental Facilities at the High Energy Frontier

    CERN Document Server

    Jenni, P.

    2016-01-01

    The main theme of the lectures covered the experimental work at hadron colliders, with a clear focus on the Large Hadron Collider (LHC) and on the roadmap that led finally to the discovery of the Higgs boson. The lectures were not a systematic course on machine and detector technologies, but rather tried to give a physics-motivated overview of many experimental aspects that were all relevant for making the discovery. The actual lectures covered a much broader scope than what is documented here in this write- up. The successful concepts for the experiments at the LHC have benefitted from the experience gained with previous generations of detectors at lower- energy machines. The lectures included also an outlook to the future experimental programme at the LHC, with its machine and experiments upgrades, as well as a short discussion of possible facilities at the high energy frontier beyond LHC.

  9. Mapping Frontier Research in the Humanities

    DEFF Research Database (Denmark)

    Knowledge production in academia today is burgeoning and increasingly interdisciplinary in nature. Research within the humanities is no exception: it is distributed across a variety of methodic styles of research and increasingly involves interactions with fields outside the narrow confines of th...... and for the organisation of the humanities and higher education?...... of the university. As a result, the notion of liberal arts and humanities within Western universities is undergoing profound transformations. In Mapping Frontier Research in the Humanities, the contributors explore this transformative process. What are the implications, both for the modes of research......Knowledge production in academia today is burgeoning and increasingly interdisciplinary in nature. Research within the humanities is no exception: it is distributed across a variety of methodic styles of research and increasingly involves interactions with fields outside the narrow confines...

  10. Frontiers International Conference on Wastewater Treatment

    CERN Document Server

    2017-01-01

    This book describes the latest research advances, innovations, and applications in the field of water management and environmental engineering as presented by leading researchers, engineers, life scientists and practitioners from around the world at the Frontiers International Conference on Wastewater Treatment (FICWTM), held in Palermo, Italy in May 2017. The topics covered are highly diverse and include the physical processes of mixing and dispersion, biological developments and mathematical modeling, such as computational fluid dynamics in wastewater, MBBR and hybrid systems, membrane bioreactors, anaerobic digestion, reduction of greenhouse gases from wastewater treatment plants, and energy optimization. The contributions amply demonstrate that the application of cost-effective technologies for waste treatment and control is urgently needed so as to implement appropriate regulatory measures that ensure pollution prevention and remediation, safeguard public health, and preserve the environment. The contrib...

  11. Frontiers in Surface Nanophotonics Principles and Applications

    CERN Document Server

    Andrews, David L

    2007-01-01

    With the rapid technical advancement of nanoscale fabrication, the science of optics has recently undergone a renaissance with the characterization of new and distinctive kinds of photonic interaction. Beyond the well-known plasmonic processes, many of these effects also arise from intricate local field effects associated with surfaces, where the surface morphology determines the detailed electromagnetic behavior. As such interactions move into practical device applications across the globe, this book presents an overview of some cutting edge developments, contributed by members of several highly renowned research groups. Copiously illustrated and with extensive references to original literature, Frontiers in Surface Nanophotonics will appeal to a wide readership with interests in optics, materials science and nanotechnology.

  12. 75 FR 2893 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-01-19

    ... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... of the Astrophysics Subcommittee of the NASA Advisory Council (NAC). This Subcommittee reports to the... following topics: --Astrophysics Division Update --Updates on Select Astrophysics Missions --Discussion of...

  13. 78 FR 2293 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-01-10

    ... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... meeting includes the following topics: --Astrophysics Division Update --NASA Astrophysics Roadmapping It...

  14. 78 FR 66384 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-11-05

    ... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics...: --Astrophysics Division Update --Presentation of Astrophysics Roadmap --Reports from Program Analysis Groups...

  15. 75 FR 51116 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-08-18

    ... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... topics: --Astrophysics Division Update --2010 Astronomy and Astrophysics Decadal Survey --Update on...

  16. Fundamental Particles and Interaction, Frontiers in Contemporary Physics: An International Lecture and Workshop Series at Vanderbilt University. Proceedings

    International Nuclear Information System (INIS)

    Panvini, R.S.; Weiler, T.J.

    1998-01-01

    These proceedings are based on papers given in the plenary sessions, lectures, and oral presentations at the Frontiers in Contemporary Physics: Fundamental Particles and Interactions Conference held in May, 1997 at Vanderbilt University in Tennessee, USA. The papers included in these proceedings cover wide ranging topics in particle physics, including hadron collider physics, electroweak physics, flavor physics, particle astrophysics, quantum chromodynamics and other particle theories etc. The Conference was widely attended. More than 130 participants took part in it; many came from non-US institutions. The full program of the talks can be found in the FCP97 web page at: http:backslash backslash fcp97.vanderbilt.edu backslash-fcp97. There were 19 papers in the proceedings, out of these, 10 have been abstracted for the Energy Science and Technology database

  17. VI School on Cosmic Rays and Astrophysics

    International Nuclear Information System (INIS)

    2017-01-01

    VI School on Cosmic Rays and Astrophysics 17-25 November 2015, Chiapas, Mexico The VI School on Cosmic Rays and Astrophysics was held at the MCTP, at the Autonomous University of Chiapas (UNACH), Tuxtla Gutiérrez, Chiapas, Mexico thanks to the Science for Development ICTP-UNACH-UNESCO Regional Seminar, 17-25 November 2015 (http://mctp.mx/e-VI-School-on-Cosmic-Rays-and-Astrophysics.html). The School series started in La Paz, Bolivia in 2004 and it has been, since then, hosted by several Latin American countires: 1.- La Paz, Bolivia (August, 2004), 2.- Puebla, Mexico (September, 2006), 3.- Arequipa, Peru (September, 2008), 4.- Santo André, Brazil (September, 2010), 5.- La Paz, Bolivia (August, 2012). It aims to promote Cosmic Ray (CR) Physics and Astrophysics in the Latin American community and to provide a general overview of theoretical and experimental issues on these topics. It is directed to undergraduates, postgraduates and active researchers in the field. The lectures introduce fundamental Cosmic Ray Physics and Astrophysics with a review of standards of the field. It is expected the school continues happening during the next years following a tradition. In this edition, the list of seminars included topics such as experimental techniques of CR detection, development of CR showers and hadronic interactions, composition and energy spectrum of primary CR, Gamma-Ray Bursts (GRBs), neutrino Astrophysics, spacecraft detectors, simulations, solar modulation, and the current state of development and results of several astroparticle physics experiments such as The Pierre Auger Observatory in Argentina, HAWC in Mexico, KASCADE and KASCADE Grande, HESS, IceCube, JEM-EUSO, Fermi-LAT, and others. This time the school has been complemented with the ICTP-UNACH-UNESCO Seminar of theory on Particle and Astroparticle Physics. The organization was done by MCTP, the Mesoamerican Centre for Theoretical Physics. The school had 46 participants, 30 students from Honduras, Brazil

  18. White paper on nuclear astrophysics and low energy nuclear physics Part 1: Nuclear astrophysics

    International Nuclear Information System (INIS)

    Arcones, Almudena; Bardayan, Dan W.

    2016-01-01

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It also summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21–23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9–10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). Our white paper is informed informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12–13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. Answers to long standing key questions are well within reach in the coming decade because of the developments outlined in this white paper.

  19. Shifting frontiers of transcendence in theology, philosophy and science

    African Journals Online (AJOL)

    Test

    2010-06-20

    Jun 20, 2010 ... of secularisation and the growing impact of a techno-scientific world view. ... well as new philosophical ideas, have done most to change our ..... Historical Jesus research, too, is just another possible shifting of frontiers based.

  20. Frontiers in Time Series and Financial Econometrics : An overview

    NARCIS (Netherlands)

    S. Ling (Shiqing); M.J. McAleer (Michael); H. Tong (Howell)

    2015-01-01

    markdownabstract__Abstract__ Two of the fastest growing frontiers in econometrics and quantitative finance are time series and financial econometrics. Significant theoretical contributions to financial econometrics have been made by experts in statistics, econometrics, mathematics, and time

  1. Frontiers in Time Series and Financial Econometrics: An Overview

    NARCIS (Netherlands)

    S. Ling (Shiqing); M.J. McAleer (Michael); H. Tong (Howell)

    2015-01-01

    markdownabstract__Abstract__ Two of the fastest growing frontiers in econometrics and quantitative finance are time series and financial econometrics. Significant theoretical contributions to financial econometrics have been made by experts in statistics, econometrics, mathematics, and time

  2. Fifth German-American Frontiers of Engineering Symposium

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-05-01

    The agenda book for the Fifth German-American Frontiers of Engineering Symposium contains abstracts of the 16 presentations as well as information on the program, bios of the speakers, contact information for all attendees, and background on the activity.

  3. Productive efficiency of tea industry: A stochastic frontier approach

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Key words: Technical efficiency, stochastic frontier, translog ... present low performance of the tea industry in Bangladesh. ... The Technical inefficiency effect .... administrative, technical, clerical, sales and purchase staff.

  4. Interpreting New Data from the High Energy Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Thaler, Jesse [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-09-26

    This is the final technical report for DOE grant DE-SC0006389, "Interpreting New Data from the High Energy Frontier", describing research accomplishments by the PI in the field of theoretical high energy physics.

  5. Chromospheric telescope of Baikal Astrophysical Observatory. New light

    Directory of Open Access Journals (Sweden)

    Skomorovsky V.I.

    2016-06-01

    Full Text Available A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at the Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a 36×24 mm detector (4000×2672 pixels was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and new calcite and quartz crystal plates were made and installed instead of damaged ones in the Hα birefringent filter (BF, manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and prefilter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Hα line core and wing.

  6. Visualization needs and techniques for astrophysical simulations

    International Nuclear Information System (INIS)

    Kapferer, W; Riser, T

    2008-01-01

    Numerical simulations have evolved continuously towards being an important field in astrophysics, equivalent to theory and observation. Due to the enormous developments in computer sciences, both hardware- and software-architecture, state-of-the-art simulations produce huge amounts of raw data with increasing complexity. In this paper some aspects of problems in the field of visualization in numerical astrophysics in combination with possible solutions are given. Commonly used visualization packages along with a newly developed approach to real-time visualization, incorporating shader programming to uncover the computational power of modern graphics cards, are presented. With these techniques at hand, real-time visualizations help scientists to understand the coherences in the results of their numerical simulations. Furthermore a fundamental problem in data analysis, i.e. coverage of metadata on how a visualization was created, is highlighted.

  7. Critical ionisation velocity effects in astrophysical plasmas

    International Nuclear Information System (INIS)

    Raadu, M.A.

    1979-08-01

    Critical ionisation velocity effects are relevant to astrophysical situations where neutral gas moves through a magnetised plasma. The experimental significance of the critical velocity is well established and the physical basis is now becoming clear. The underlying mechanism depends on the combined effects of electron impact ionisation and electron energisation by collective plasma interactions. For low density plasmas a theory based on a circular process involving electron heating through a modified two stream instability has been developed. Several applications of critical velocity effects to astrophysical plasmas have been discussed in the literature. The importance of the effect in any particular case may be determined from a detailed consideration of energy and momentum balance, using appropriate atomic rate coefficients and taking full account of collective plasma processes. (Auth.)

  8. International Conference on Particle Physics and Astrophysics

    CERN Document Server

    2015-01-01

    The International Conference on Particle Physics and Astrophysics (ICPPA-2015) will be held in Moscow, Russia, from October 5 to 10, 2015. The conference is organized by Center of Basic Research and Particle Physics of National Research Nuclear University “MEPhI”. The aim of the Conference is to promote contacts between scientists and development of new ideas in fundamental research. Therefore we will bring together experts and young scientists working on experimental and theoretical aspects of nuclear, particle, astroparticle physics and cosmology. ICPPA-2015, aims to present the most recent results in astrophysics and collider physics and reports from the main experiments currently taking data. The working languages of the conference are English and Russian.

  9. Underground nuclear astrophysics at the Dresden Felsenkeller

    Energy Technology Data Exchange (ETDEWEB)

    Bemmerer, Daniel; Ilgner, Christoph; Junghans, Arnd R.; Mueller, Stefan; Rimarzig, Bernd; Schwengner, Ronald; Szuecs, Tamas; Wagner, Andreas [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Cowan, Thomas E.; Gohl, Stefan; Grieger, Marcel; Reinicke, Stefan; Roeder, Marko; Schmidt, Konrad; Stoeckel, Klaus; Takacs, Marcell P.; Wagner, Louis [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Technische Universitaet Dresden (Germany); Reinhardt, Tobias P.; Zuber, Kai [Technische Universitaet Dresden (Germany)

    2015-07-01

    Favored by the low background underground, accelerator-based experiments are an important tool to study nuclear astrophysics reactions involving stable charged particles. This technique has been used with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies, as well as the continuation of solar fusion studies. As a result, NuPECC strongly recommended the installation of one or more higher-energy underground accelerators. Such a project is underway in Dresden. A 5 MV Pelletron accelerator is currently being refurbished by installing an ion source on the high voltage terminal, enabling intensive helium beams. The preparation of the underground site is funded, and the civil engineering project is being updated. The science case, operational strategy and project status are reported.

  10. Numerical Methods for Radiation Magnetohydrodynamics in Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R I; Stone, J M

    2007-11-20

    We describe numerical methods for solving the equations of radiation magnetohydrodynamics (MHD) for astrophysical fluid flow. Such methods are essential for the investigation of the time-dependent and multidimensional dynamics of a variety of astrophysical systems, although our particular interest is motivated by problems in star formation. Over the past few years, the authors have been members of two parallel code development efforts, and this review reflects that organization. In particular, we discuss numerical methods for MHD as implemented in the Athena code, and numerical methods for radiation hydrodynamics as implemented in the Orion code. We discuss the challenges introduced by the use of adaptive mesh refinement in both codes, as well as the most promising directions for future developments.

  11. Status reports of supercomputing astrophysics in Japan

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Nagasawa, Mikio

    1990-01-01

    The Workshop on Supercomputing Astrophysics was held at National Laboratory for High Energy Physics (KEK, Tsukuba) from August 31 to September 2, 1989. More than 40 participants of physicists, astronomers were attendant and discussed many topics in the informal atmosphere. The main purpose of this workshop was focused on the theoretical activities in computational astrophysics in Japan. It was also aimed to promote effective collaboration between the numerical experimentists working on supercomputing technique. The various subjects of the presented papers of hydrodynamics, plasma physics, gravitating systems, radiative transfer and general relativity are all stimulating. In fact, these numerical calculations become possible now in Japan owing to the power of Japanese supercomputer such as HITAC S820, Fujitsu VP400E and NEC SX-2. (J.P.N.)

  12. Modern fluid dynamics for physics and astrophysics

    CERN Document Server

    Regev, Oded; Yecko, Philip A

    2016-01-01

    This book grew out of the need to provide students with a solid introduction to modern fluid dynamics. It offers a broad grounding in the underlying principles and techniques used, with some emphasis on applications in astrophysics and planetary science. The book comprehensively covers recent developments, methods and techniques, including, for example, new ideas on transitions to turbulence (via transiently growing stable linear modes), new approaches to turbulence (which remains the enigma of fluid dynamics), and the use of asymptotic approximation methods, which can give analytical or semi-analytical results and complement fully numerical treatments. The authors also briefly discuss some important considerations to be taken into account when developing a numerical code for computer simulation of fluid flows. Although the text is populated throughout with examples and problems from the field of astrophysics and planetary science, the text is eminently suitable as a general introduction to fluid dynamics. It...

  13. The Future of Gamma Ray Astrophysics

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Over the past decade, gamma ray astrophysics has entered the astrophysical mainstream. Extremely successful space-borne (GeV) and ground-based (TeV) detectors, combined with a multitude of partner telescopes, have revealed a fascinating “astroscape" of active galactic nuclei, pulsars, gamma ray bursts, supernova remnants, binary stars, star-forming galaxies, novae much more, exhibiting major pathways along which large energy releases can flow. From  a basic physics perspective, exquisitely sensitive measurements have constrained the nature of dark matter, the cosmological origin of magnetic field and the properties of black holes. These advances have motivated the development of new facilities, including HAWC, DAMPE, CTA and SVOM, which will further our understanding of the high energy universe. Topics that will receive special attention include merging neutron star binaries, clusters of galaxies, galactic cosmic rays and putative, TeV dark matter.

  14. Neutrino particle astrophysics: status and outlook

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The discovery of astrophysical neutrinos at high energy by IceCube raises a host of questions: What are the sources? Is there a Galactic as well as an extragalactic component? How does the astrophysical spectrum continue to lower energy where the dominant signal is from atmospheric neutrinos? Is there a measureable flux of cosmogenic neutrinos at higher energy? What is the connection to cosmic rays? At what level and in what energy region should we expect to see evidence of the π0 decay photons that must accompany the neutrinos at production? Such questions are stimulating much theoretical activity and many multi-wavelength follow-up observations as well as driving plans for new detectors. My goal in this presentation will be to connect the neutrino data and their possible interpretations to ongoing multi-messenger observations and to the design of future detectors.

  15. Exploring Astrophysical Magnetohydrodynamics in the Laboratory

    Science.gov (United States)

    Manuel, Mario

    2014-10-01

    Plasma evolution in many astrophysical systems is dominated by magnetohydrodynamics. Specifically of interest to this talk are collimated outflows from accretion systems. Away from the central object, the Euler equations can represent the plasma dynamics well and may be scaled to a laboratory system. We have performed experiments to investigate the effects of a background magnetic field on an otherwise hydrodynamically collimated plasma. Laser-irradiated, cone targets produce hydrodynamically collimated plasma jets and a pulse-powered solenoid provides a constant background magnetic field. The application of this field is shown to completely disrupt the original flow and a new magnetically-collimated, hollow envelope is produced. Results from these experiments and potential implications for their astrophysical analogs will be discussed.

  16. Numerical Methods for Radiation Magnetohydrodynamics in Astrophysics

    International Nuclear Information System (INIS)

    Klein, R I; Stone, J M

    2007-01-01

    We describe numerical methods for solving the equations of radiation magnetohydrodynamics (MHD) for astrophysical fluid flow. Such methods are essential for the investigation of the time-dependent and multidimensional dynamics of a variety of astrophysical systems, although our particular interest is motivated by problems in star formation. Over the past few years, the authors have been members of two parallel code development efforts, and this review reflects that organization. In particular, we discuss numerical methods for MHD as implemented in the Athena code, and numerical methods for radiation hydrodynamics as implemented in the Orion code. We discuss the challenges introduced by the use of adaptive mesh refinement in both codes, as well as the most promising directions for future developments

  17. Global kinetic theory of astrophysical jets

    International Nuclear Information System (INIS)

    Chang, T.

    1989-01-01

    We suggest that an astrophysical plasma stream flowing outward from a central object aling an open magnetic field line with decreasing field strength generally will have anisotropic velocity distributions. I particular, the electron distribution function of this type of plasma streams will contain a 'thermally populated' region and a stretche out high energy tail (or 'jet-like') region collimated in the utward direction of the magnetic field line. Our argument is based on a global, collisional, kinetic theory. Because the 'kinetic jets' are always pointed aling the outward direction of the field lines, thy are automatically collimated and will assume whatever the peculiar geometries dictated by the magnetic field. This result should be useful in the understanding of the basic structures of such diverse astrophysical objects as the extragalactic radio jets, stellar winds, the solar wind, planetary polar winds, and galactic jets. (author). 8 refs.; 2 figs

  18. The Trojan horse method in nuclear astrophysics

    International Nuclear Information System (INIS)

    Aliotta, M.; Rolfs, C.; Lattuada, M.; Pellegriti, M.G.; Pizzone, R.G.; Spitaleri, C.; Miljanic, Dj.; Typel, S.; Wolter, H.H.

    2001-01-01

    Because of the Coulomb barrier, reaction cross sections in astrophysics cannot be accessed directly at the relevant Gamow energies, unless very favourable conditions are met (e.g. LUNA--underground experiments). Theoretical extrapolations of available data are then needed to derive the astrophysical S(0)-factor. Various indirect processes have been used in order to obtain additional information on the parameters entering these extrapolations. The Trojan Horse Method is an indirect method which might help to bypass some of the problems typically encountered in direct measurements, namely the presence of the Coulomb barrier and the effect of the electron screening. However, a comparison with direct data in an appropriate energy region (e.g. around the Coulomb barrier) is crucial before extending the method to the relevant Gamow energy. Additionally, experimental and theoretical tests are needed to validate the assumptions underlying the method. The application of the Trojan Horse Method to some cases of interest is discussed

  19. Coulomb dissociation studies for astrophysical thermonuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Motobayashi, T [Dept. of Physics, Rikkyo Univ., Toshima, Tokyo (Japan)

    1998-06-01

    The Coulomb dissociation method was applied to several radiative capture processes of astrophysical interest. The method has an advantage of high experimental efficiency, which allow measurements with radioactive nuclear beams. The reactions {sup 13}N(p,{gamma}){sup 14}O and {sup 7}Be(p,{gamma}){sup 8}B are mainly discussed. They are the key reaction in the hot CNO cycle in massive stars and the one closely related to the solar neutrino problem, respectively. (orig.)

  20. Neutrino masses in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Raffelt, G.G.

    1996-01-01

    Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations may well solve the solar neutrino problem, and can have a significant impact on supernova physics. (author) 14 figs., tabs., 33 refs

  1. An anelastic approximation arising in astrophysics

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Feireisl, Eduard

    2017-01-01

    Roč. 369, 3-4 (2017), s. 1573-1597 ISSN 0025-5831 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Navier-Stokes system * astrophysics Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.314, year: 2016 https://link.springer.com/article/10.1007%2Fs00208-016-1507-x

  2. Astrophysical and terrestrial neutrinos in Supernova detectors

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1985-09-01

    Supernova (SN) explosions are the place of very fundamental phenomena, whose privileged messengers are neutrinos. But such events are very rare. Then, SN detection has to be combined with other purposes. The recent developments of SN detectors have been associated with developments of underground particle physics (proton decay, monopoles ...). But here, I will restrict myself to discuss the possibilities for a supernova detector to be sensitive to other sources of neutrinos, astrophysical or terrestrial

  3. Neutrino masses in astrophysics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Raffelt, G G [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    1996-11-01

    Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations may well solve the solar neutrino problem, and can have a significant impact on supernova physics. (author) 14 figs., tabs., 33 refs.

  4. Carbon dioxide and climate: an astrophysical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, R S

    1979-01-01

    In this survey the earth is viewed from the astrophysical perspective, i.e. using global mean values of environmental parameters. The role of carbon dioxide is described in the processes of energy transfer from the earth's surface to space, which determine global climate as measured by the mean surface temperature. Analogies and differences between the problems of the terrestrial atmosphere and those of the solar and stellar atmospheres are examined, both in the computation of model atmospheres and in remote sensing of atmospheric temperature and composition. Subsequently, the temporal astrophysical perspective, with a review of the evolution of CO/sub 2/ abundance and climate on astrophysical or geological time scales, on earth as an Venus (the runaway greenhouse) and on Mars is introduced. Variation of CO/sub 2/ may have been critical to the maintenance of an environment in which life could originate and evolve, and may itself have been affected by life. On human time scales, the recent and continuing increase in atmospheric CO/sub 2/ raises new problems, which are briefly surveyed. It is argued, that the differential greenhouse effect of increased CO/sub 2/ in the earth's atmosphere is essentially identifical to the blanketing effect of spectral lines on the temperature structure of stellar atmospheres. The methods used by astrophysicists in such studies are reviewed and compared with those used to evaluate the differential greenhouse effect of CO/sub 2/ in radiative-convective models of the earth's atmosphere. The latter methods remain relatively crude, but recent results by different authors are in reasonably good agreement; however, the astrophysical perspective, i.e. the use of one-dimensional global mean models, remains a gross simplification of the real complexity of the earth's climate system, which is also true in stellar atmospheres.

  5. A mean-variance frontier in discrete and continuous time

    OpenAIRE

    Bekker, Paul A.

    2004-01-01

    The paper presents a mean-variance frontier based on dynamic frictionless investment strategies in continuous time. The result applies to a finite number of risky assets whose price process is given by multivariate geometric Brownian motion with deterministically varying coefficients. The derivation is based on the solution for the frontier in discrete time. Using the same multiperiod framework as Li and Ng (2000), I provide an alternative derivation and an alternative formulation of the solu...

  6. Karakteristik Kurva Efisien Frontier dalam Menentukan Portofolio Optimal

    Directory of Open Access Journals (Sweden)

    epha diana supandi

    2016-06-01

    Full Text Available Pada tulisan ini karakteristik kurva efisien frontier pada model portofolio Markowitz diteliti secara matematis. Portofolio optimal diperoleh dengan menggunakan metode Lagrange. Pada penelitian ini juga dikaji karakteristik portofolio optimal pada portofolio minimum variance, portofolio tangency dan portofolio mean-variance serta posisinya pada kurva efisien frontier. Lebih lanjut untuk memberikan gambaran yang lebih konkrit maka diberikan contoh numerik pada beberapa saham yang diperdagangkan di pasar modal Indonesia.

  7. Business practice: The rise of American astrophysics, 1859--1919

    Science.gov (United States)

    Nisbett, Catherine Elaine

    This dissertation takes seriously the production of astrophysical data by examining observatory practices through the lens of business models. The post- Civil War American industrial and commercial landscape experienced large-scale reorganization and expansion; alongside that transformation, astrophysics became a discipline unto itself, and practitioners developed a professional identity. During this time the Harvard College Observatory (HCO), in particular, came into the business of catalogue production and the staff and management adopted many of the industrial and commercial processes that became standards of American business, such as forms of mass production and modern management. The projects astrophysicists chose, and those that came to define astrophysics as distinct from the "old" astronomy of celestial mechanics and astrometry, required substantially more funding for expensive instruments than other observational astronomy projects. These constraints consolidated the discipline in the hands of fewer, established professionals at institutions usually affiliated with universities or the government. The HCO, though it adopted industrial organizational models, was not a for-profit business, and the match between business practices and knowledge production was sometimes uneasy. The dissertation is concerned with this match between business models and scientific enterprise, and is motivated by three general questions. First, what compelled people to invest in an undertaking for which the benefit was in recognition rather than in dividends? Second, what did employees think they were working toward, in terms of products of their labor and in terms of pay--- both symbolic and financial? And third, what were the products of this scientific production; what were the criteria for success? These were active, though not explicit, concerns in the lives of donors, observatory employees and upper management. The HCO's fourth director, Edward Pickering, would come to court

  8. Physics and astrophysics with gamma-ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Vandenbroucke, J. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2012-08-15

    In the past few years gamma-ray astronomy has entered a golden age. A modern suite of telescopes is now scanning the sky over both hemispheres and over six orders of magnitude in energy. At {approx}TeV energies, only a handful of sources were known a decade ago, but the current generation of ground-based imaging atmospheric Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) has increased this number to nearly one hundred. With a large field of view and duty cycle, the Tibet and Milagro air shower detectors have demonstrated the promise of the direct particle detection technique for TeV gamma rays. At {approx}GeV energies, the Fermi Gamma-ray Space Telescope has increased the number of known sources by nearly an order of magnitude in its first year of operation. New classes of sources that were previously theorized to be gamma-ray emitters have now been confirmed observationally. Moreover, there have been surprise discoveries of GeV gamma-ray emission from source classes for which no theory predicted it was possible. In addition to elucidating the processes of high-energy astrophysics, gamma-ray telescopes are making essential contributions to fundamental physics topics including quantum gravity, gravitational waves, and dark matter. I summarize the current census of astrophysical gamma-ray sources, highlight some recent discoveries relevant to fundamental physics, and describe the synergetic connections between gamma-ray and neutrino astronomy. This is a brief overview intended in particular for particle physicists and neutrino astronomers, based on a presentation at the Neutrino 2010 conference in Athens, Greece. I focus in particular on results from Fermi (which was launched soon after Neutrino 2008), and conclude with a description of the next generation of instruments, namely HAWC and the Cherenkov Telescope Array.

  9. Cosmology and particle astrophysics. 2. ed.

    International Nuclear Information System (INIS)

    Bergstroem, L.; Goobar, A.

    2006-01-01

    Beginning with some basic facts about the observable universe the authors consider in successive chapters the complete range of topics that make up a degree course in cosmology and particle astrophysics. The outstanding feature of this book is that it is self-contained, in that no specialised knowledge is required on the part of the reader, apart from basic undergraduate mathematics and physics. This paperback edition will again target students of physics, astrophysics and cosmology at the advanced undergraduate level or early graduate level. One of the book's biggest strong points is that the authors rapidly involve students in the most exciting of today's developments in the field in a simple and self-contained manner, relegating the more technical aspects to appendices. The worked examples throughout the book, and summaries at the end of each chapter, which were expanded in the second edition, have been very well received by students. This book offers advanced undergraduate level and beginning graduate level students a highly readable, yet comprehensive review of particle astrophysics. Competing books cover this topic at too advanced a level for this readership. (orig.)

  10. Heavy ion irradiation of astrophysical ice analogs

    International Nuclear Information System (INIS)

    Duarte, Eduardo Seperuelo; Domaracka, Alicja; Boduch, Philippe; Rothard, Hermann; Balanzat, Emmanuel; Dartois, Emmanuel; Pilling, Sergio; Farenzena, Lucio; Frota da Silveira, Enio

    2009-01-01

    Icy grain mantles consist of small molecules containing hydrogen, carbon, oxygen and nitrogen atoms (e.g. H 2 O, GO, CO 2 , NH 3 ). Such ices, present in different astrophysical environments (giant planets satellites, comets, dense clouds, and protoplanetary disks), are subjected to irradiation of different energetic particles: UV radiation, ion bombardment (solar and stellar wind as well as galactic cosmic rays), and secondary electrons due to cosmic ray ionization of H 2 . The interaction of these particles with astrophysical ice analogs has been the object of research over the last decades. However, there is a lack of information on the effects induced by the heavy ion component of cosmic rays in the electronic energy loss regime. The aim of the present work is to simulate of the astrophysical environment where ice mantles are exposed to the heavy ion cosmic ray irradiation. Sample ice films at 13 K were irradiated by nickel ions with energies in the 1-10 MeV/u range and analyzed by means of FTIR spectrometry. Nickel ions were used because their energy deposition is similar to that deposited by iron ions, which are particularly abundant cosmic rays amongst the heaviest ones. In this work the effects caused by nickel ions on condensed gases are studied (destruction and production of molecules as well as associated cross sections, sputtering yields) and compared with respective values for light ions and UV photons. (authors)

  11. Traversable braneworld wormholes supported by astrophysical observations

    Science.gov (United States)

    Wang, Deng; Meng, Xin-He

    2018-02-01

    In this study, we investigate the characteristics and properties of a traversable wormhole constrained by the current astrophysical observations in the framework of modified theories of gravity (MOG). As a concrete case, we study traversable wormhole space-time configurations in the Dvali-Gabadadze-Porrati (DGP) braneworld scenario, which are supported by the effects of the gravity leakage of extra dimensions. We find that the wormhole space-time structure will open in terms of the 2 σ confidence level when we utilize the joint constraints supernovae (SNe) Ia + observational Hubble parameter data (OHD) + Planck + gravitational wave (GW) and z based on various energy conditions; (ii) we can offer a strict restriction to the local wormhole space-time structure by using the current astrophysical observations; and (iii) we can clearly identify a physical gravitational resource for the wormholes supported by astrophysical observations, namely the dark energy components of the universe or equivalent space-time curvature effects from MOG. Moreover, we find that the strong energy condition is always violated at low redshifts.

  12. Goddard's Astrophysics Science Division Annual Report 2013

    Science.gov (United States)

    Weaver, Kimberly A. (Editor); Reddy, Francis J. (Editor); Tyler, Patricia A. (Editor)

    2014-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for two orbiting astrophysics missions Fermi Gamma-ray Space Telescope and Swift as well as the Science Support Center for Fermi. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical community, and enable future missions by conceiving new concepts and inventing new technologies.

  13. The Astrophysics Science Division Annual Report 2009

    Science.gov (United States)

    Oegerle, William (Editor); Reddy, Francis (Editor); Tyler, Pat (Editor)

    2010-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum - from gamma rays to radio wavelengths - as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions - WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical community, and enable future missions by conceiving new concepts and inventing new technologies.

  14. Goddard's Astrophysics Science Division Annual Report 2011

    Science.gov (United States)

    Centrella, Joan; Reddy, Francis; Tyler, Pat

    2012-01-01

    The Astrophysics Science Division(ASD) at Goddard Space Flight Center(GSFC)is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radiowavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contract imaging techniques to serch for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, and provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and suppport the astronomical community, and enable future missions by conceiving new conepts and inventing new technologies.

  15. Instrumentation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides instrumentation support for flight tests of prototype weapons systems using a vast array of airborne sensors, transducers, signal conditioning and encoding...

  16. Thick Disks in the Hubble Space Telescope Frontier Fields

    Energy Technology Data Exchange (ETDEWEB)

    Elmegreen, Bruce G. [IBM Research Division, T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Elmegreen, Debra Meloy; Tompkins, Brittany; Jenks, Leah G., E-mail: bge@us.ibm.com, E-mail: elmegreen@vassar.edu [Department of Physics and Astronomy, Vassar College, Poughkeepsie, NY 12604 (United States)

    2017-09-20

    Thick disk evolution is studied using edge-on galaxies in two Hubble Space Telescope Frontier Field Parallels. The galaxies were separated into 72 clumpy types and 35 spiral types with bulges. Perpendicular light profiles in F435W, F606W, and F814W ( B , V , and I ) passbands were measured at 1 pixel intervals along the major axes and fitted to sech{sup 2} functions convolved with the instrument line spread function (LSF). The LSF was determined from the average point spread function of ∼20 stars in each passband and field, convolved with a line of uniform brightness to simulate disk blurring. A spread function for a clumpy disk was also used for comparison. The resulting scale heights were found to be proportional to galactic mass, with the average height for a 10{sup 10±0.5} M {sub ⊙} galaxy at z = 2 ± 0.5 equal to 0.63 ± 0.24 kpc. This value is probably the result of a blend between thin and thick disk components that cannot be resolved. Evidence for such two-component structure is present in an inverse correlation between height and midplane surface brightness. Models suggest that the thick disk is observed best between the clumps, and there the average scale height is 1.06 ± 0.43 kpc for the same mass and redshift. A 0.63 ± 0.68 mag V − I color differential with height is also evidence for a mixture of thin and thick components.

  17. Theoretical Research at the High Energy Frontier: Cosmology and Beyond

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Lawrence M. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics and School of Earth and Space Exploration

    2017-03-31

    Radiation. Undoubtedly the most significant outstanding problem in high-energy physics is also a problem in cosmology, and indeed originated not from accelerators but from astrophysical observations: What is the origin and nature of the dark energy that appears to dominate the Universe? An understanding of quantum gravity, and perhaps a new understanding of quantum mechanics or quantum field theory may be required to fully address this problem. At the moment, the physics of black holes may provide the best opportunity to explore these issues, while the discovery of the Higgs suggests several new possible connections to physics that might be relevant for dark energy. Finally, pending confirmation of a gravitational wave signal from inflation, to date the only direct evidence for fundamental particle physics beyond the standard model comes, at least in part, from astrophysical neutrino observations. A remarkable convergence of theory, observation and experiment has been taking place that is allowing great strides to be made in our knowledge of the parameters that describe the universe, if not the origin of these parameters. Given the new discoveries now being made, and the incredible capabilities of future instruments, it is an exciting time to make progress in our fundamental understanding the origin and evolution of the Universe and the fundamental forces that guide that evolution. As a result, it is natural that our DOE theory research program at Arizona State University focuses in large part on the connections between particle physics and cosmology and astrophysics in order to improve our understanding of fundamental physics. Our areas of research cover all of the areas described above. Our group now consists of four faculty PI’s and their postdocs and students, complemented by long term visitor Frank Wilczek, and physics faculty colleagues Cecilia Lunardini, Richard Lebed, and Andrei Belitsky, whose interests overlap in areas ranging from particle theory and

  18. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    astrophysical context of the observation. The observational techniques chosen vary in dependence of the observed phenomenon. One major goal of especially Chapters 3 and 4 is to prove by successful explorative observations the scientific perspectives of the new instruments. Chapter 3 deals with the pioneering interferometric infrared study of stellar sources and their surroundings in the immediate vicinity of the SMBH at the center of the Milky Way. I was able to use the resolving power of an optical large baseline interferometer (OLBI) to investigate for the first time the different structures and excitation conditions of interstellar and circumstellar dust in 200 mpc distance to the SMBH. It is unknown whether the standard models for star and dust formation, which themselves dominate the infrared appearance of an inactive galaxy as the Milky Way, still apply under the strong tidal forces of gravity, exerted by the central SMBH. During the course of my doctoral research, I worked 2.5 years within the VLT Interferometry (VLTI) group of the European Southern Observatory (ESO) in M"unchen and Chile. I obtained the very first infrared fringes on GC sources and investigated the different instrument capabilities at the current sensitivity limit of the VLTI. The VLTI is the world leading stellar interferometric facility providing the infrastructure to combine the light of up to four 8m-class Adaptive Optics corrected telescopes, which themselves represent the state-of-the-art of optical-infrared telescope technology. The accomplished work includes the investigation of different data reduction techniques with respect to maximum accuracy and signal-to-noise ratios. The VLTI is right in the process of construction. While first modes are already open to the astronomical community, several advanced modes and instruments are still at different preliminary stages, ranging from early design studies to advanced instrument commissioning. The experiences of my VLTI observations, fully exploiting

  19. Frontiers of higher order fuzzy sets

    CERN Document Server

    Tahayori, Hooman

    2015-01-01

    Frontiers of Higher Order Fuzzy Sets, strives to improve the theoretical aspects of general and Interval Type-2 fuzzy sets and provides a unified representation theorem for higher order fuzzy sets. Moreover, the book elaborates on the concept of gradual elements and their integration with the higher order fuzzy sets. This book also introduces new frameworks for information granulation based on general T2FSs, IT2FSs, Gradual elements, Shadowed sets and rough sets. In particular, the properties and characteristics of the new proposed frameworks are studied. Such new frameworks are shown to be more capable to be exploited in real applications. Higher order fuzzy sets that are the result of the integration of general T2FSs, IT2FSs, gradual elements, shadowed sets and rough sets will be shown to be suitable to be applied in the fields of bioinformatics, business, management, ambient intelligence, medicine, cloud computing and smart grids. Presents new variations of fuzzy set frameworks and new areas of applicabili...

  20. Considerations on Energy Frontier Colliders after LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-11-15

    Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

  1. New frontiers in pediatric Allo-SCT.

    Science.gov (United States)

    Talano, J M; Pulsipher, M A; Symons, H J; Militano, O; Shereck, E B; Giller, R H; Hancock, L; Morris, E; Cairo, M S

    2014-09-01

    The inaugural meeting of 'New Frontiers in Pediatric Allogeneic Stem Cell Transplantation' organized by the Pediatric Blood and Transplant Consortium (PBMTC) was held at the American Society of Pediatric Hematology and Oncology Annual Meeting. This meeting provided an international platform for physicians and investigators active in the research and utilization of pediatric Allo-SCT in children and adolescents with malignant and non-malignant disease (NMD), to share information and develop future collaborative strategies. The primary objectives of the conference included: (1) to present advances in Allo-SCT in pediatric ALL and novel pre and post-transplant immunotherapy; (2) to highlight new strategies in alternative allogeneic stem cell donor sources for children and adolescents with non-malignant hematological disorders; (3) to discuss timing of immune reconstitution after Allo-SCT and methods of facilitating more rapid recovery of immunity; (4) to identify strategies of utilizing Allo-SCT in pediatric myeloproliferative disorders; (5) to develop diagnostic and therapeutic approaches to hematological complications post pediatric Allo-SCT; (6) to enhance the understanding of new novel cellular therapeutic approaches to pediatric malignant and non-malignant hematological disorders; and (7) to discuss optimizing drug therapy in pediatric recipients of Allo-SCT. This paper will provide a brief overview of the conference.

  2. Frontier research at ANSTO with neutrons

    International Nuclear Information System (INIS)

    Gadd, G.E.

    1999-01-01

    In the last decade there has been considerable interest in the new form of carbon called fullerenes. Instead of hexagonal rings of carbon atoms arranged in planar sheets in graphite or a 3-D tetrahedral structure in diamond, this new form of carbon consists of closed cages of carbon atoms. The fullerene which has gained the most notoriety has been C 60, 'buckminsterfullerene' or 'buckyballs'. This has the geometry of a soccer ball where the carbon atoms correspond to the vertices of the seams. As well as these cages, long hollow tubes of carbon have also been formed called carbon nanotubes. These new carbon materials are poised to create new technologies in the fields of new materials, superconductors, electronic components, medical drugs, radioisotopes and radiotracers. At ANSTO the strategy of combining frontier research with the use of neutrons has been taken, to try and produce a useful end product related to our core activities. The research has focussed on trying to trap atoms (molecules) inside the centre of fullerene cages and in particular C 60 or in the solid fullerene lattice in the spaces between the closely packed cages. Neutrons from our research nuclear reactor serve a two-fold purpose. Neutron diffraction has been used to elucidate the crystal structure of the new materials followed by neutron irradiation to activate the trapped species for possible uses in radiopharmaceutical and industrial radiotracer applications. (author)

  3. EFISIENSI BANK PEMBANGUNAN DAERAH: PENDEKATAN STOCHASTIC FRONTIER

    Directory of Open Access Journals (Sweden)

    Ahmad Husein Fadhlullah

    2016-01-01

    Full Text Available The objective of this research is to analyze the efficiency rate at Islamic regional banks (BPD in Indonesia, with case of 15 Islamic regional banks from 2008 – 2012. The method that used in this research is stochastic frontier analysis approach (SFA, which uses the input variable (such as human resources cost, administration cost, and other expenses and the output variable is SFA (operational income. The average efficiency rate from 15 Islamic regional banks from 2008 – 2012 with SFA method is 53.21 percent and all of the Islamic regional banks doesn’t achieve the 100 percent efficiency. The most efficient banks is Islamic regional bank of Kalimantan Barat which the efficiency rate achieve 90.42 percent and the most inefficiency banks is Islamic regional bank of Sumatera Barat. The average efficiency rate from 2008-2012 is always increase each year. In 2008 the average efficiency rate only 33.57 percent and in the last of 2012 achieve 71.81 percent.DOI: 10.15408/sjie.v4i1.2291

  4. All About Audio Equalization: Solutions and Frontiers

    Directory of Open Access Journals (Sweden)

    Vesa Välimäki

    2016-05-01

    Full Text Available Audio equalization is a vast and active research area. The extent of research means that one often cannot identify the preferred technique for a particular problem. This review paper bridges those gaps, systemically providing a deep understanding of the problems and approaches in audio equalization, their relative merits and applications. Digital signal processing techniques for modifying the spectral balance in audio signals and applications of these techniques are reviewed, ranging from classic equalizers to emerging designs based on new advances in signal processing and machine learning. Emphasis is placed on putting the range of approaches within a common mathematical and conceptual framework. The application areas discussed herein are diverse, and include well-defined, solvable problems of filter design subject to constraints, as well as newly emerging challenges that touch on problems in semantics, perception and human computer interaction. Case studies are given in order to illustrate key concepts and how they are applied in practice. We also recommend preferred signal processing approaches for important audio equalization problems. Finally, we discuss current challenges and the uncharted frontiers in this field. The source code for methods discussed in this paper is made available at https://code.soundsoftware.ac.uk/projects/allaboutaudioeq.

  5. Frontiers of advanced engineering materials (faem-06)

    International Nuclear Information System (INIS)

    Alam, S.; Mirza, J.A.

    2006-01-01

    The second international conference on Frontiers of Advanced Engineering Materials was held on 04-06 December 2006 in Lahore, Pakistan. At a time of the rapid expending enormous potential for the wide spread development and usage of Advanced Engineering Materials. About 121 papers were presented by engineers and scientists from 30 organizations, academic institutions and foreign experts from six countries. on the recommendation of a panel after review, only 72 papers were included in this conference proceedings. The main areas of interest which remained under focus during the conference were structure property relationship, surface Modifications, Nano Technology, Super and semi conductors, Magnetic Materials, Materials Proceeding, Glass and Ceramics, Composite Materials. This Conference open a way to help in strengthening the bounds between our foreign guests local and delegates. The participants showed their keen interest in the poster sessions. Fruitful conclusions of these presentations will be helpful to give rise to new topics of research in the fields of advanced engineering Materials. (A.B.)

  6. Aviation Frontiers: On-Demand Aircraft

    Science.gov (United States)

    Moore, Mark D.

    2010-01-01

    Throughout the 20th Century, NASA has defined the forefront of aeronautical technology, and the aviation industry owes much of its prosperity to this knowledge and technology. In recent decades, centralized aeronautics has become a mature discipline, which raises questions concerning the future aviation innovation frontiers. Three transformational aviation capabilities, bounded together by the development of a Free Flight airspace management system, have the potential to transform 21st Century society as profoundly as civil aviation transformed the 20th Century. These mobility breakthroughs will re-establish environmental sustainable centralized aviation, while opening up latent markets for civil distributed sensing and on-demand rural and regional transportation. Of these three transformations, on-demand aviation has the potential to have the largest market and productivity improvement to society. The information system revolution over the past 20 years shows that vehicles lead, and the interconnecting infrastructure to make them more effective follows; that is, unless on-demand aircraft are pioneered, a distributed Air Traffic Control system will likely never be established. There is no single technology long-pole that will enable on-demand vehicle solutions. However, fully digital aircraft that include electric propulsion has the potential to be a multi-disciplinary initiator of solid state technologies that can provide order of magnitude improvements in the ease of use, safety/reliability, community and environmental friendliness, and affordability.

  7. X-ray instrumentation in astronomy

    International Nuclear Information System (INIS)

    Cuhlane, J.L.

    1985-01-01

    This book presents the proceedings of a conference devoted to x-ray instrumentation in astronomy. Special sections are: AXAF X-Ray Optical Systems; Specialized X-Ray Systems; X-Ray Optical Systems I; X-Ray Optical Systems II; Gas Filled X-Ray Detectors II; The NASA Advanced X-Ray Astrophysics Facility; X-Ray and EUV Spectrometers; Microchannel Plates; and Solid State Detectors

  8. Frontiers in the economics of energy efficiency

    International Nuclear Information System (INIS)

    Miguel, Carlos de; Labandeira, Xavier; Löschel, Andreas

    2015-01-01

    Energy efficiency has become an essential instrument to obtain effective greenhouse gas mitigation and reduced energy dependence. This introductory article contextualizes the contributions of the supplemental issue by showing the new setting for energy efficiency economics and policy; discussing the role of price instruments to promote energy savings; presenting new approaches for energy efficiency policies; and placing energy efficiency within a wider energy and environmental framework.

  9. Instrumentation development

    International Nuclear Information System (INIS)

    Ubbes, W.F.; Yow, J.L. Jr.

    1988-01-01

    Instrumentation is developed for the Civilian Radioactive Waste Management Program to meet several different (and sometimes conflicting) objectives. This paper addresses instrumentation development for data needs that are related either directly or indirectly to a repository site, but does not touch on instrumentation for work with waste forms or other materials. Consequently, this implies a relatively large scale for the measurements, and an in situ setting for instrument performance. In this context, instruments are needed for site characterization to define phenomena, develop models, and obtain parameter values, and for later design and performance confirmation testing in the constructed repository. The former set of applications is more immediate, and is driven by the needs of program design and performance assessment activities. A host of general technical and nontechnical issues have arisen to challenge instrumentation development. Instruments can be classed into geomechanical, geohydrologic, or other specialty categories, but these issues cut across artificial classifications. These issues are outlined. Despite this imposing list of issues, several case histories are cited to evaluate progress in the area

  10. Astrophysics and the exploration of the universe

    International Nuclear Information System (INIS)

    Turck-Chieze, S.; Garcia, R.A.; Brun, A.S.; Minier, V.; Andre, Ph.; Motte, F.; Mathis, St.; Foglizzo, Th.; Decourchelle, A.; Ballet, J.; Chaty, S.; Corbel, St.; Rodriguez, J.; Brahic, A.; Charnoz, S.; Ferrari, C.; Lagage, P.O.; Masset, F.; Pantin, E.; Sauvage, M.; Galliano, F.; Goldwurm, A.; Ballet, J.; Decourchelle, A.; Grenier, I.; Daddi, E.; Elbaz, D.; Bournaud, F.; Yvon, D.; Arnaud, M.; Teyssier, R.; Lehoucq, R.; Palanque-Delabrouille, N.; Lehoucq, R.; Cirelli, M.; Bonvin, C.; Mansoulie, B.; Ruhlmann-Kleider, V.; Refregier, A.; Brax, Ph.; Lavignac, St.; Starck, J.L.; Talvard, M.; Sauvage, M.; Cara, Ch.; Lagage, P.O.; Ferrari, C.; Rodriguez, L.; Sauvageot, J.L.; Lebrun, F.; Grenier, I.; Glicenstein, J.F.; Gerbier, G.

    2009-01-01

    This special issue of Clefs CEA journal is entirely devoted to astrophysics and to the exploration and probing of the Universe. A first part of this dossier, described here, makes a status of our present day knowledge about stars, planets, galaxies, the Universe structure and dark matter. Content: 1 - Stars seed the Universe: What does the Sun tell us?, Probing stellar interiors, From the Sun to the stars, A tour of stellar nurseries, How heavy elements arise, How supernovae explode, Supernova remnants, High-energy objects - sources for astonishment, Focus: A Probing the Universe across the entire light spectrum; 2 - Planets: a dance of small bodies, swirling around up to the finale of their birth: How our world was born, The rings of Saturn: a magnificent research laboratory, Planetary cocoons; 3 - Galaxies: a richly paradoxical evolution: The active life of galaxies, A mysterious black hole, Elucidating the cosmic ray acceleration mechanism, Seeking out the great ancestors, The formation of galaxies: a story of paradoxes, The morphogenesis of galaxies; 4 - The Universe, a homogeneous 'soup' that has turned into a hierarchical structure: The grand thermal history of the Universe, The cosmic web, The formation of the structures of the Universe: the interplay of models, Does the Universe have a shape? Is it finite, or infinite?; 5 - Odyssey across the dark side of the Universe: The puzzle of dark matter, Astrophysics and the observation of dark matter, The theory of dark matter, Could dark matter be generated some day at LHC? A Universe dominated by dark energy, Astrophysics and the observation of dark energy, Theories of dark energy, The matter-antimatter asymmetry of the Universe; 6 - Journey into the lights of the Universe: Microwave - ESA Planck Surveyor, Submillimeter and infrared - ArTeMis, Herschel Space Observatory, VLT-VISIR, Cassini-CIRS, Visible - SoHo-GOLF, X-ray - XMM-Newton, Gamma ray - INTEGRAL, Fermi Gamma-Ray Space Telescope, HESS, EDELWEISS

  11. Modeling the astrophysical dynamical process with laser-plasmas

    International Nuclear Information System (INIS)

    Xia Jiangfan; Zhang Jun; Zhang Jie

    2001-01-01

    The use of the state-of-the-art laser facility makes it possible to create conditions of the same or similar to those in the astrophysical processes. The introduction of the astrophysics-relevant ideas in laser-plasma experiments is propitious to the understanding of the astrophysical phenomena. However, the great difference between the laser-produced plasmas and the astrophysical processes makes it awkward to model the latter by laser-plasma experiments. The author addresses the physical backgrounds for modeling the astrophysical plasmas by laser plasmas, connecting these two kinds of plasmas by scaling laws. Thus, allowing the creation of experimental test beds where observations and models can be quantitatively compared with laser-plasma data. Special attentions are paid on the possibilities of using home-made laser facilities to model astrophysical phenomena

  12. Stopping Power Measurements: Implications in Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Carmen Angulo; Thierry Delbar; Jean-Sebastien Graulich; Pierre Leleux

    1999-01-01

    The stopping powers of C, CH 2 , Al, Ni, and polyvinylchloride (PVC) for several light ions ( 9 Be, 11 B, 12 C, 14 N, 16 O, 19 F, 20 Ne) with an incident energy of 1 MeV/amu have been measured at the Louvain-la-Neuve cyclotron facility. Stopping powers are given relative to the one for 5.5 MeV 4 He ions with an uncertainty of less than 1%. We compare our results with two widely used semiempirical models and we discuss some implications in nuclear astrophysics studies

  13. Relativistic Astrophysics and Cosmology: A Primer

    International Nuclear Information System (INIS)

    Abramowicz, Marek A

    2007-01-01

    'Relativistic Astrophysics and Cosmology: A Primer' by Peter Hoyng, was published last year by Springer. The book is based on lectures given by the author at University of Utrecht to advanced undergraduates. This is a short and scholarly book. In about 300 pages, the author has covered the most interesting and important applications of Albert Einstein's general relativity in present-day astrophysics and cosmology: black holes, neutron stars, gravitational waves, and the cosmic microwave background. The book stresses theory, but also discusses several experimental and observational topics, such as the Gravity Probe B mission, interferometer detectors of gravitational waves and the power spectrum of the cosmic microwave background. The coverage is not uniform. Some topics are discussed in depth, others are only briefly mentioned. The book obviously reflects the author's own research interests and his preferences for specific mathematical methods, and the choice of the original artwork that illustrates the book (and appears on its cover) is a very personal one. I consider this personal touch an advantage, even if I do not always agree with the author's choices. For example, I employ Killing vectors as a very useful mathematical tool not only in my research on black holes, but also in my classes. I find that my students prefer it when discussions of particle, photon and fluid motion in the Schwarzschild and Kerr spacetimes are based explicitly and directly on the Killing vectors rather than on coordinate calculations. The latter approach is, of course, the traditional one, and is used in Peter Hoyng's book. Reading the book is a stimulating experience, because the reader can almost feel the author's presence. The author's opinions, his mathematical taste, his research pleasures, and his pedagogical passion are apparent everywhere. Lecturers contemplating a new course on relativistic astrophysics could adopt Hoyng's book as the text. Their students will be in the author

  14. Astrophysical constraints on scalar field models

    International Nuclear Information System (INIS)

    Bertolami, O.; Paramos, J.

    2005-01-01

    We use stellar structure dynamics arguments to extract bounds on the relevant parameters of two scalar field models: the putative scalar field mediator of a fifth force with a Yukawa potential and the new variable mass particle models. We also analyze the impact of a constant solar inbound acceleration, such as the one reported by the Pioneer anomaly, on stellar astrophysics. We consider the polytropic gas model to estimate the effect of these models on the hydrostatic equilibrium equation and fundamental quantities such as the central temperature. The current bound on the solar luminosity is used to constrain the relevant parameters of each model

  15. Physics, Astrophysics and Cosmology with Gravitational Waves

    Directory of Open Access Journals (Sweden)

    Sathyaprakash B. S.

    2009-03-01

    Full Text Available Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers, and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.

  16. Dimensional analysis and group theory in astrophysics

    CERN Document Server

    Kurth, Rudolf

    2013-01-01

    Dimensional Analysis and Group Theory in Astrophysics describes how dimensional analysis, refined by mathematical regularity hypotheses, can be applied to purely qualitative physical assumptions. The book focuses on the continuous spectral of the stars and the mass-luminosity relationship. The text discusses the technique of dimensional analysis, covering both relativistic phenomena and the stellar systems. The book also explains the fundamental conclusion of dimensional analysis, wherein the unknown functions shall be given certain specified forms. The Wien and Stefan-Boltzmann Laws can be si

  17. Nonlinear evolution of astrophysical Alfven waves

    Science.gov (United States)

    Spangler, S. R.

    1984-01-01

    Nonlinear Alfven waves were studied using the derivative nonlinear Schrodinger equation as a model. The evolution of initial conditions, such as envelope solitons, amplitude-modulated waves, and band-limited noise was investigated. The last two furnish models for naturally occurring Alfven waves in an astrophysical plasma. A collapse instability in which a wave packet becomes more intense and of smaller spatial extent was analyzed. It is argued that this instability leads to enhanced plasma heating. In studies in which the waves are amplified by an electron beam, the instability tends to modestly inhibit wave growth.

  18. Nuclear Data on Unstable Nuclei for Astrophysics

    International Nuclear Information System (INIS)

    Smith, Michael Scott; Meyer, Richard A; Lingerfelt, Eric; Scott, J.P.; Hix, William Raphael; Ma, Zhanwen; Bardayan, Daniel W.; Blackmon, Jeff C.; Guidry, Mike W.; KOZUB, RAYMOND L.; Chae, Kyung YuK.

    2004-01-01

    Recent measurements with radioactive beams at ORNL's Holifield Radioactive Ion Beam Facility (HRIBF) have prompted the evaluation of a number of reactions involving unstable nuclei needed for stellar explosion studies. We discuss these evaluations, as well as the development of a new computational infrastructure to enable the rapid incorporation of the latest nuclear physics results in astrophysics models. This infrastructure includes programs that simplify the generation of reaction rates, manage rate databases, and visualize reaction rates, all hosted at a new website http://www.nucastrodata.org

  19. Quark matter in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Olinto, A.V.

    1987-10-01

    We dicuss the role of quark matter in astrophysics and cosmology. The implications of the dynamics of the quark-hadron phase transition in the early universe for the element abundances from big bang nucleosynthesis and the composition of the dark matter in the universe are addressed. We discuss the possibility of deciding on an equation of state for high density matter by observing the cooling of a neutron star remnant of SN1987A. Quark matter models for the Centauros events, Cygnus X-3 cosmic ray events, high energy gamma-ray bursts and the solar neutrino problem are described. 25 refs., 3 figs

  20. Precision Astrophysics Experiments with the Kepler Satellite

    Science.gov (United States)

    Jackiewicz, Jason

    2012-10-01

    Long photometric observations from space of tens of thousands of stars, such as those provided by Kepler, offer unique opportunities to carry out ensemble astrophysics as well as detailed studies of individual objects. One of the primary tools at our disposal for understanding pulsating stars is asteroseismology, which uses observed stellar oscillation frequencies to determine interior properties. This can provide very strict constraints on theories of stellar evolution, structure, and the population characteristics of stars in the Milky Way galaxy. This talk will focus on several of the exciting insights Kepler has enabled through asteroseismology of stars across the H-R diagram.

  1. Physics, Astrophysics and Cosmology with Gravitational Waves.

    Science.gov (United States)

    Sathyaprakash, B S; Schutz, Bernard F

    2009-01-01

    Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.

  2. Showing Complex Astrophysical Settings Through Virtual Reality

    Science.gov (United States)

    Green, Joel; Smith, Denise; Smith, Louis Chad; Lawton, Brandon; Lockwood, Alexandra; Jirdeh, Hussein

    2018-01-01

    The James Webb Space Telescope (JWST), NASA’s next great observatory launching in spring 2019, will routinely showcase astrophysical concepts that will challenge the public's understanding. Emerging technologies such as virtual reality bring the viewer into the data and the concept in previously unimaginable immersive detail. For example, we imagine a spacefarer inside a protoplanetary disk, seeing the accretion process directly. STScI is pioneering some tools related to JWST for showcasing at AAS, and in local events, which I highlight here. If we develop materials properly tailored to this medium, we can reach more diverse audiences than ever before.

  3. NASA's Long-Term Astrophysics Data Archives

    OpenAIRE

    Rebull, L. M.; Desai, V.; Teplitz, H.; Groom, S.; Akeson, R.; Berriman, G. B.; Helou, G.; Imel, D.; Mazzarella, J. M.; Accomazzi, A.; McGlynn, T.; Smale, A.; White, R.

    2017-01-01

    NASA regards data handling and archiving as an integral part of space missions, and has a strong track record of serving astrophysics data to the public, beginning with the the IRAS satellite in 1983. Archives enable a major science return on the significant investment required to develop a space mission. In fact, the presence and accessibility of an archive can more than double the number of papers resulting from the data. In order for the community to be able to use the data, they have to b...

  4. Alpha resonant scattering for astrophysical reaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study (CNS), University of Tokyo, RIKEN campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y.; Kubano, S. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayakawa, S. [Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95125 Catania (Italy); Kawabata, T. [Department of Physics, Kyoto University, Kita-Shirakawa, Kyoto 606-8502 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-811 (Korea, Republic of); Binh, D. N. [30 MeV Cyclotron Center, Tran Hung Dao Hospital, Hoan Kiem District, Hanoi (Viet Nam); Khiem, L. H.; Duy, N. G. [Institute of Physics, Vietnam Academy of Science and Technology, 18 Hong Quoc Viet, Nghia do, Hanoi (Viet Nam)

    2014-05-02

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(α,γ) reaction, and proposed a new cluster band in {sup 11}C.

  5. Alpha resonant scattering for astrophysical reaction studies

    International Nuclear Information System (INIS)

    Yamaguchi, H.; Kahl, D.; Nakao, T.; Wakabayashi, Y.; Kubano, S.; Hashimoto, T.; Hayakawa, S.; Kawabata, T.; Iwasa, N.; Teranishi, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. G.

    2014-01-01

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of 7 Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the 7 Be(α,γ) reaction, and proposed a new cluster band in 11 C

  6. Old and New from Multifrequency Astrophysics

    Directory of Open Access Journals (Sweden)

    Franco Giovannelli

    2014-12-01

    Full Text Available In this short review paper we comment on some the most important steps that have been made in the past decades for a better understanding of the physics governing our Universe. The results we discuss come from the many groundand-space-based experiments developed for measuring astrophysical sources in various energy bands. These experimental results are discussed within the framework of current theoretical models. Because of the limited length of this paper, we have selected only a few topics that, in our opinion, have been crucial for the progress of our understanding of the physics of cosmic sources.

  7. Introduction to stellar astrophysics. V. 1

    International Nuclear Information System (INIS)

    Boehm-Vitense, E.

    1989-01-01

    This textbook introduces basic elements of fundamental astronomy and astrophysics which serve as a foundation for understanding the structure, evolution, and observed properties of stars. The first half of the book explains how stellar motions, distances, luminosities, colours, radii, masses and temperatures are measured or derived. The author then shows how data of these sorts can be arranged to classify stars through their spectra. Stellar rotation and stellar magnetic fields are introduced. Stars with peculiar spectra and pulsating stars also merit special attention. The endpoints of stellar evolutions are briefly described. There is a separate chapter on the Sun and a final one on interstellar absorption. (author)

  8. SPACE PHYSICS: Developing resources for astrophysics at A-level: the TRUMP Astrophysics project

    Science.gov (United States)

    Swinbank, Elizabeth

    1997-01-01

    After outlining the astrophysical options now available in A-level physics syllabuses, this paper notes some of the particular challenges facing A-level teachers and students who chose these options and describes a project designed to support them. The paper highlights some key features of the project that could readily be incorporated into other areas of physics curriculum development.

  9. Instrumental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-15

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  10. Instrumental analysis

    International Nuclear Information System (INIS)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-01

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  11. LOFT instrumentation

    International Nuclear Information System (INIS)

    Bixby, W.W.

    1979-01-01

    A description of instrumentation used in the Loss-of-Fluid Test (LOFT) large break Loss-of-Coolant Experiments is presented. Emphasis is placed on hydraulic and thermal measurements in the primary system piping and components, reactor vessel, and pressure suppression system. In addition, instrumentation which is being considered for measurement of phenomena during future small break testing is discussed. (orig.) 891 HP/orig. 892 BRE [de

  12. Intracluster light at the Frontier: A2744

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Mireia; Trujillo, Ignacio, E-mail: mireia.montes.quiles@gmail.com [Instituto de Astrofísica de Canarias,c/Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain)

    2014-10-20

    The ultra-deep multiwavelength Hubble Space Telescope Frontier Fields coverage of the Abell Cluster 2744 is used to derive the stellar population properties of its intracluster light (ICL). The restframe colors of the ICL of this intermediate redshift (z = 0.3064) massive cluster are bluer (g – r = 0.68 ± 0.04; i – J = 0.56 ± 0.01) than those found in the stellar populations of its main galaxy members (g – r = 0.83 ± 0.01; i – J = 0.75 ± 0.01). Based on these colors, we derive the following mean metallicity Z = 0.018 ± 0.007 for the ICL. The ICL age is 6 ± 3 Gyr younger than the average age of the most massive galaxies of the cluster. The fraction of stellar mass in the ICL component comprises at least 6% of the total stellar mass of the galaxy cluster. Our data are consistent with a scenario where the bulk of the ICL of A2744 has been formed relatively recently (z < 1). The stellar population properties of the ICL suggest that this diffuse component is mainly the result of the disruption of infalling galaxies with similar characteristics in mass (M {sub *} ∼ 3 × 10{sup 10} M {sub ☉}) and metallicity than our own Milky Way. The amount of ICL mass in the central part of the cluster (<400 kpc) is equivalent to the disruption of 4-6 Milky-Way-type galaxies.

  13. AHP 28: Review: China's 'Tibetan' Frontiers

    Directory of Open Access Journals (Sweden)

    Benno Ryan Weiner

    2013-12-01

    Full Text Available In recent years, the study of China's minorities has become something of an ethnographic subgenre. Given the political sensitivities involved, however, it is unsurprising that relatively little of this fieldwork has been conducted among populations the Chinese state defines as 'Tibetan'. Beth Merriam's important new addition to the literature, China's 'Tibetan' Frontiers, begins to fill this gap. However, as the author is quick to point out, hers is not an ethnography of Tibet or Tibetans, nor the ethno-cultural region of Khams, or even Yushu Prefecture. It is, instead, an intensely local, "school-based study" (10 of Trinde (Khri 'du, Chenduo Township, a remote, eponymously named county seat in the far south of Qinghai Province. Meriam spent fourteen months (2002-2003 as the first foreign teacher at Trinde County Nationalities Middle School. Her inquiry is focused on the region's cultural elite, "a small educated class of the local population" (10 primarily consisting of the school's directors and teachers, but also students, work unit functionaries, cadres, and NGO administrators. "Rather than analysing a specific 'ethnic group,' or political structure," Meriam writes, her study "proceeds from a critical vantage point of practices and concepts associated with a number of broadly-defined political themes and social contexts" (292. The result is a compelling and sophisticated ethnography that not only problematizes the Chinese state's narratives of national(ity unity, but also those disseminated within the exile Tibetan community. Moreover, Meriam explicitly challenges the English-language field of "Tibetan studies," in which "nationality rubrics are also commonly invoked as discrete, homogenous, and unambiguous objects of knowledge" (290. As suggested by the book's title, she summarizes, "A key argument of this ethnography is that context and practice are more appropriate bases for analysis than 'ethnicity,' 'identity' or 'Tibetans'" (147.

  14. Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

    CERN Document Server

    Carraminana, Alberto

    2007-01-01

    This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level intermediate between a graduate student and a young researcher. The book includes also three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics. This book is a valuable complement not only for research but also for lecturers in specialized course of high energy astrophysics, cosmic ray astrophysics and particle physics.

  15. New Worlds, New Horizons in Astronomy and Astrophysics

    National Research Council Canada - National Science Library

    2010-01-01

    .... Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysic...

  16. Nuclear Data for Astrophysics Research: A New Online Paradigm

    International Nuclear Information System (INIS)

    Smith, Michael Scott

    2011-01-01

    Our knowledge of a wide range of astrophysical processes depends crucially on nuclear physics data. While new nuclear information is being generated at an ever-increasing rate, the methods to process this information into astrophysical simulations have changed little over the decades and cannot keep pace. Working online, 'cloud computing', may be the methodology breakthrough needed to ensure that the latest nuclear data quickly gets into astrophysics codes. The successes of the first utilization of cloud computing for nuclear astrophysics will be described. The advantages of cloud computing for the broader nuclear data community are also discussed.

  17. Demonstration of Submillimeter Astrophysics Technology at Caltech Submillimeter Observatory

    Data.gov (United States)

    National Aeronautics and Space Administration — Detector technology developments will determine the science product of future astrophysics missions and projects, and this is especially true at submillimeter...

  18. ZAPP: The Z Astrophysical Plasma Properties collaboration

    International Nuclear Information System (INIS)

    Rochau, G. A.; Bailey, J. E.; Falcon, R. E.; Loisel, G. P.; Nagayama, T.; Mancini, R. C.; Hall, I.; Winget, D. E.; Montgomery, M. H.; Liedahl, D. A.

    2014-01-01

    The Z Facility at Sandia National Laboratories [Matzen et al., Phys. Plasmas 12, 055503 (2005)] provides MJ-class x-ray sources that can emit powers >0.3 PW. This capability enables benchmark experiments of fundamental material properties in radiation-heated matter at conditions previously unattainable in the laboratory. Experiments on Z can produce uniform, long-lived, and large plasmas with volumes up to 20 cc, temperatures from 1–200 eV, and electron densities from 10 17–23  cc −1 . These unique characteristics and the ability to radiatively heat multiple experiments in a single shot have led to a new effort called the Z Astrophysical Plasma Properties (ZAPP) collaboration. The focus of the ZAPP collaboration is to reproduce the radiation and material characteristics of astrophysical plasmas as closely as possible in the laboratory and use detailed spectral measurements to strengthen models for atoms in plasmas. Specific issues under investigation include the LTE opacity of iron at stellar-interior conditions, photoionization around active galactic nuclei, the efficiency of resonant Auger destruction in black-hole accretion disks, and H-Balmer line shapes in white dwarf photospheres

  19. Ultraviolet and Visible Emission Mechanisms in Astrophysics

    Science.gov (United States)

    Stancil, Phillip C.; Schultz, David R.

    2003-01-01

    The project involved the study of ultraviolet (UV) and visible emission mechanisms in astrophysical and atmospheric environments. In many situations, the emission is a direct consequence of a charge transferring collision of an ion with a neutral with capture of an electron to an excited state of the product ion. The process is also important in establishing the ionization and thermal balance of an astrophysical plasma. As little of the necessary collision data are available, the main thrust of the project was the calculation of total and state-selective charge transfer cross sections and rate coefficients for a very large number of collision systems. The data was computed using modern explicit techniques including the molecular-orbital close-coupling (MOCC), classical trajectory Monte Carlo (CTMC), and continuum distorted wave (CDW) methods. Estimates were also made in some instances using the multichannel Landau-Zener (MCLZ) and classical over-the-barrier (COB) models. Much of the data which has been computed has been formatted for inclusion in a charge transfer database on the World Wide Web (cfadc.phy.ornl.gov/astro/ps/data/). A considerable amount of data has been generated during the lifetime of the grant. Some of it has not been analyzed, but it will be as soon as possible, the data placed on our website, and papers ultimately written.

  20. Summary of sessions on nuclear astrophysics

    Science.gov (United States)

    Rolfs, C.

    In the minds of some there exists the patronizing belief that nuclear physics is a mature science. The same is not believed about nuclear astrophysics, which has been an active branch of astrophysics for over fifty years, but is now in the midst of an exciting revival in experimental and theoretical research around the world. The ultimate goal is to understand how nuclear processes generate the energy of stars over their lifetimes and, in doing so, synthesize heavier elements from the primordial hydrogen and helium produced in the Big Bang, which led to the expanding universe. Impressive progress has been made in this goal and this was rewarded. However, there are major puzzles, such as the solar neutrino problem to name just one, which challenge the fundaments of the field. To solve these problems, new nuclear physics data are needed employing novel experimental techniques such as radioactive ion beams and underground accelerator facilities. Without such new data, much of the work done so far will - in an optimistic view - be incomplete and - in a pessimistic view - be possibly wrong. Thus, new data do not represent a fine structure information or a cleaning-up job, but they represent the major next step in this exciting field&

  1. Time-symmetric integration in astrophysics

    Science.gov (United States)

    Hernandez, David M.; Bertschinger, Edmund

    2018-04-01

    Calculating the long-term solution of ordinary differential equations, such as those of the N-body problem, is central to understanding a wide range of dynamics in astrophysics, from galaxy formation to planetary chaos. Because generally no analytic solution exists to these equations, researchers rely on numerical methods that are prone to various errors. In an effort to mitigate these errors, powerful symplectic integrators have been employed. But symplectic integrators can be severely limited because they are not compatible with adaptive stepping and thus they have difficulty in accommodating changing time and length scales. A promising alternative is time-reversible integration, which can handle adaptive time-stepping, but the errors due to time-reversible integration in astrophysics are less understood. The goal of this work is to study analytically and numerically the errors caused by time-reversible integration, with and without adaptive stepping. We derive the modified differential equations of these integrators to perform the error analysis. As an example, we consider the trapezoidal rule, a reversible non-symplectic integrator, and show that it gives secular energy error increase for a pendulum problem and for a Hénon-Heiles orbit. We conclude that using reversible integration does not guarantee good energy conservation and that, when possible, use of symplectic integrators is favoured. We also show that time-symmetry and time-reversibility are properties that are distinct for an integrator.

  2. Communicating the Science from NASA's Astrophysics Missions

    Science.gov (United States)

    Hasan, Hashima; Smith, Denise A.

    2015-01-01

    Communicating science from NASA's Astrophysics missions has multiple objectives, which leads to a multi-faceted approach. While a timely dissemination of knowledge to the scientific community follows the time-honored process of publication in peer reviewed journals, NASA delivers newsworthy research result to the public through news releases, its websites and social media. Knowledge in greater depth is infused into the educational system by the creation of educational material and teacher workshops that engage students and educators in cutting-edge NASA Astrophysics discoveries. Yet another avenue for the general public to learn about the science and technology through NASA missions is through exhibits at museums, science centers, libraries and other public venues. Examples of the variety of ways NASA conveys the excitement of its scientific discoveries to students, educators and the general public will be discussed in this talk. A brief overview of NASA's participation in the International Year of Light will also be given, as well as of the celebration of the twenty-fifth year of the launch of the Hubble Space Telescope.

  3. Fundamental symmetries and astrophysics with radioactive beams

    International Nuclear Information System (INIS)

    Vogt, E.

    1996-04-01

    A major new initiative at TRIUMF pertains to the use of radioactive beams for astrophysics and for fundamental symmetry experiments. Some recent work is described in which the β-decay-followed by alpha particle emission of 16 N was used to find the resonance parameters dominating the alpha particle capture in 12 C and thus to find the astrophysical S-factor of this reaction which is of crucial importance for alpha-particle burning and the subsequent collapse of stars. In some work underway trapped neural atoms of radioactive potassium atoms will be used to study fundamental symmetries of the weak interactions. Trapping has been achieved and soon 38m K decay will be used to search for evidence of scalar interactions and 37 K decay to search for right-handed gauge-bosom interactions. Future experiments are planned to look for parity non-conservation in trapped francium atoms. This program is part of a revitalization for the TRIUMF laboratory accompanied by the construction of the radioactive beam facility (ISAC). (author)

  4. Astrophysical Model Selection in Gravitational Wave Astronomy

    Science.gov (United States)

    Adams, Matthew R.; Cornish, Neil J.; Littenberg, Tyson B.

    2012-01-01

    Theoretical studies in gravitational wave astronomy have mostly focused on the information that can be extracted from individual detections, such as the mass of a binary system and its location in space. Here we consider how the information from multiple detections can be used to constrain astrophysical population models. This seemingly simple problem is made challenging by the high dimensionality and high degree of correlation in the parameter spaces that describe the signals, and by the complexity of the astrophysical models, which can also depend on a large number of parameters, some of which might not be directly constrained by the observations. We present a method for constraining population models using a hierarchical Bayesian modeling approach which simultaneously infers the source parameters and population model and provides the joint probability distributions for both. We illustrate this approach by considering the constraints that can be placed on population models for galactic white dwarf binaries using a future space-based gravitational wave detector. We find that a mission that is able to resolve approximately 5000 of the shortest period binaries will be able to constrain the population model parameters, including the chirp mass distribution and a characteristic galaxy disk radius to within a few percent. This compares favorably to existing bounds, where electromagnetic observations of stars in the galaxy constrain disk radii to within 20%.

  5. ‘Firewall’ phenomenology with astrophysical neutrinos

    Science.gov (United States)

    Afshordi, Niayesh; Yazdi, Yasaman K.

    2016-12-01

    One of the most fundamental features of a black hole in general relativity is its event horizon: a boundary from which nothing can escape. There has been a recent surge of interest in the nature of these event horizons and their local neighbourhoods. In an attempt to resolve black hole information paradox(es), and more generally, to better understand the path towards quantum gravity, ‘firewalls’ have been proposed as an alternative to black hole event horizons. In this paper, we explore the phenomenological implications of black holes possessing a surface or ‘firewall’, and predict a potentially detectable signature of these firewalls in the form of a high energy astrophysical neutrino flux. We compute the spectrum of this neutrino flux in different models and show that it is a possible candidate for the source of the PeV neutrinos recently detected by IceCube. This opens up a new area of research, bridging the non-perturbative physics of quantum gravity with the observational black hole and high energy astrophysics.

  6. ‘Firewall’ phenomenology with astrophysical neutrinos

    International Nuclear Information System (INIS)

    Afshordi, Niayesh; Yazdi, Yasaman K

    2016-01-01

    One of the most fundamental features of a black hole in general relativity is its event horizon: a boundary from which nothing can escape. There has been a recent surge of interest in the nature of these event horizons and their local neighbourhoods. In an attempt to resolve black hole information paradox(es), and more generally, to better understand the path towards quantum gravity, ‘firewalls’ have been proposed as an alternative to black hole event horizons. In this paper, we explore the phenomenological implications of black holes possessing a surface or ‘firewall’, and predict a potentially detectable signature of these firewalls in the form of a high energy astrophysical neutrino flux. We compute the spectrum of this neutrino flux in different models and show that it is a possible candidate for the source of the PeV neutrinos recently detected by IceCube. This opens up a new area of research, bridging the non-perturbative physics of quantum gravity with the observational black hole and high energy astrophysics. (paper)

  7. Art as a Vehicle for Nuclear Astrophysics

    Science.gov (United States)

    Kilburn, Micha

    2013-04-01

    One aim of the The Joint Institute for Nuclear Astrophysics (JINA) is to teach K-12 students concepts and ideas related to nuclear astrophysics. For students who have not yet seen the periodic table, this can be daunting, and we often begin with astronomy concepts. The field of astronomy naturally lends itself to an art connection through its beautiful images. Our Art 2 Science programming adopts a hands-on approach by teaching astronomy through student created art projects. This approach engages the students, through tactile means, visually and spatially. For younger students, we also include physics based craft projects that facilitate the assimilation of problem solving skills. The arts can be useful for aural and kinetic learners as well. Our program also includes singing and dancing to songs with lyrics that teach physics and astronomy concepts. The Art 2 Science programming has been successfully used in after-school programs at schools, community centers, and art studios. We have even expanded the program into a popular week long summer camp. I will discuss our methods, projects, specific goals, and survey results for JINA's Art 2 Science programs.

  8. The CATS Service: An Astrophysical Research Tool

    Directory of Open Access Journals (Sweden)

    O V Verkhodanov

    2009-03-01

    Full Text Available We describe the current status of CATS (astrophysical CATalogs Support system, a publicly accessible tool maintained at Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS (http://cats.sao.ru allowing one to search hundreds of catalogs of astronomical objects discovered all along the electromagnetic spectrum. Our emphasis is mainly on catalogs of radio continuum sources observed from 10 MHz to 245 GHz, and secondly on catalogs of objects such as radio and active stars, X-ray binaries, planetary nebulae, HII regions, supernova remnants, pulsars, nearby and radio galaxies, AGN and quasars. CATS also includes the catalogs from the largest extragalactic surveys with non-radio waves. In 2008 CATS comprised a total of about 109 records from over 400 catalogs in the radio, IR, optical and X-ray windows, including most source catalogs deriving from observations with the Russian radio telescope RATAN-600. CATS offers several search tools through different ways of access, e.g. via Web-interface and e-mail. Since its creation in 1997 CATS has managed about 105requests. Currently CATS is used by external users about 1500 times per day and since its opening to the public in 1997 has received about 4000 requests for its selection and matching tasks.

  9. Advancing Astrophysics with the Square Kilometre Array

    CERN Document Server

    Fender, Rob; Govoni, Federica; Green, Jimi; Hoare, Melvin; Jarvis, Matt; Johnston-Hollitt, Melanie; Keane, Evan; Koopmans, Leon; Kramer, Michael; Maartens, Roy; Macquart, Jean-Pierre; Mellema, Garrelt; Oosterloo, Tom; Prandoni, Isabella; Pritchard, Jonathan; Santos, Mario; Seymour, Nick; Stappers, Ben; Staveley-Smith, Lister; Tian, Wen Wu; Umana, Grazia; Wagg, Jeff; Bourke, Tyler L; AASKA14

    2015-01-01

    In 2014 it was 10 years since the publication of the comprehensive ‘Science with the Square Kilometre Array’ book and 15 years since the first such volume appeared in 1999. In that time numerous and unexpected advances have been made in the fields of astronomy and physics relevant to the capabilities of the Square Kilometre Array (SKA). The SKA itself progressed from an idea to a developing reality with a baselined Phase 1 design (SKA1) and construction planned from 2017. To facilitate the publication of a new, updated science book, which will be relevant to the current astrophysical context, the meeting "Advancing Astrophysics with the Square Kilometre Array" was held in Giardina Naxos, Sicily. Articles were solicited from the community for that meeting to document the scientific advances enabled by the first phase of the SKA and those pertaining to future SKA deployments, with expected gains of 5 times the Phase 1 sensitivity below 350 MHz, about 10 times the Phase 1 sensitivity above 350 MHz and with f...

  10. Black Hole Astrophysics The Engine Paradigm

    CERN Document Server

    Meier, David L

    2012-01-01

    As a result of significant research over the past 20 years, black holes are now linked to some of the most spectacular and exciting phenomena in the Universe, ranging in size from those that have the same mass as stars to the super-massive objects that lie at the heart of most galaxies, including our own Milky Way. This book first introduces the properties of simple isolated holes, then adds in complications like rotation, accretion, radiation, and magnetic fields, finally arriving at a basic understanding of how these immense engines work. Black Hole Astrophysics • reviews our current knowledge of cosmic black holes and how they generate the most powerful observed pheonomena in the Universe; • highlights the latest, most up-to-date theories and discoveries in this very active area of astrophysical research; • demonstrates why we believe that black holes are responsible for important phenomena such as quasars, microquasars and gammaray bursts; • explains to the reader the nature of the violent and spe...

  11. Two families of astrophysical diverging lens models

    Science.gov (United States)

    Er, Xinzhong; Rogers, Adam

    2018-03-01

    In the standard gravitational lensing scenario, rays from a background source are bent in the direction of a foreground lensing mass distribution. Diverging lens behaviour produces deflections in the opposite sense to gravitational lensing, and is also of astrophysical interest. In fact, diverging lensing due to compact distributions of plasma has been proposed as an explanation for the extreme scattering events that produce frequency-dependent dimming of extragalactic radio sources, and may also be related to the refractive radio wave phenomena observed to affect the flux density of pulsars. In this work we study the behaviour of two families of astrophysical diverging lenses in the geometric optics limit, the power law, and the exponential plasma lenses. Generally, the members of these model families show distinct behaviour in terms of image formation and magnification, however the inclusion of a finite core for certain power-law lenses can produce a caustic and critical curve morphology that is similar to the well-studied Gaussian plasma lens. Both model families can produce dual radial critical curves, a novel distinction from the tangential distortion usually produced by gravitational (converging) lenses. The deflection angle and magnification of a plasma lens vary with the observational frequency, producing wavelength-dependent magnifications that alter the amplitudes and the shape of the light curves. Thus, multiwavelength observations can be used to physically constrain the distribution of the electron density in such lenses.

  12. Magnetic Reconnection in Extreme Astrophysical Environments

    Science.gov (United States)

    Uzdensky, Dmitri

    Magnetic reconnection is a fundamental plasma physics process of breaking ideal-MHD's frozen-in constraints on magnetic field connectivity and of dramatic rearranging of the magnetic topol-ogy, which often leads to a violent release of the free magnetic energy. Reconnection has long been acknowledged to be of great importance in laboratory plasma physics (magnetic fusion) and in space and solar physics (responsible for solar flares and magnetospheric substorms). In addition, its importance in Astrophysics has been increasingly recognized in recent years. However, due to a great diversity of astrophysical environments, the fundamental physics of astrophysical magnetic reconnection can be quite different from that of the traditional recon-nection encountered in the solar system. In particular, environments like the solar corona and the magnetosphere are characterized by relatively low energy densities, where the plasma is ad-equately described as a mixture of electrons and ions whose numbers are conserved and where the dissipated magnetic energy basically stays with the plasma. In contrast, in many high-energy astrophysical phenomena the energy density is so large that photons play as important a role as electrons and ions and, in particular, radiation pressure and radiative cooling become dominant. In this talk I focus on the most extreme case of high-energy-density astrophysical reconnec-tion — reconnection of magnetar-strength (1014 - 1015 Gauss) magnetic fields, important for giant flares in soft-gamma repeaters (SGRs), and for rapid magnetic energy release in either the central engines or in the relativistic jets of Gamma Ray Bursts (GRBs). I outline the key relevant physical processes and present a new theoretical picture of magnetic reconnection in these environments. The corresponding magnetic energy density is so enormous that, when suddenly released, it inevitably heats the plasma to relativistic temperatures, resulting in co-pious production of electron

  13. The Polarimeter for Relativistic Astrophysical X-ray Sources

    Science.gov (United States)

    Jahoda, Keith; Kallman, Timothy R.; Kouveliotou, Chryssa; Angelini, Lorella; Black, J. Kevin; Hill, Joanne E.; Jaeger, Theodore; Kaaret, Philip E.; Markwardt, Craig B.; Okajima, Takashi; Petre, Robert; Schnittman, Jeremy; Soong, Yang; Strohmayer, Tod E.; Tamagawa, Toru; Tawara, Yuzuru

    2016-07-01

    The Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) is one of three Small Explorer (SMEX) missions selected by NASA for Phase A study, with a launch date in 2020. The PRAXyS Observatory exploits grazing incidence X-ray mirrors and Time Projection Chamber Polarimeters capable of measuring the linear polarization of cosmic X-ray sources in the 2-10 keV band. PRAXyS combines well-characterized instruments with spacecraft rotation to ensure low systematic errors. The PRAXyS payload is developed at the Goddard Space Flight Center with the Johns Hopkins University Applied Physics Laboratory, University of Iowa, and RIKEN (JAXA) collaborating on the Polarimeter Assembly. The LEOStar-2 spacecraft bus is developed by Orbital ATK, which also supplies the extendable optical bench that enables the Observatory to be compatible with a Pegasus class launch vehicle. A nine month primary mission will provide sensitive observations of multiple black hole and neutron star sources, where theory predicts polarization is a strong diagnostic, as well as exploratory observations of other high energy sources. The primary mission data will be released to the community rapidly and a Guest Observer extended mission will be vigorously proposed.

  14. Polar Balloon Experiment for Astrophysics Research (Polar BEAR)

    Science.gov (United States)

    Bashindzhagyan, G.; Adams, James H., Jr.; Bashindzhagyan, P.; Chilingarian, A.; Donnelly, J.; Drury, L.; Egorov, N.; Golubkov, S.; Grebenyuk, V.; Kalinin, A.; hide

    2001-01-01

    A new balloon experiment is proposed for a long duration flight around the North Pole. The primary objective of the experiment is to measure the elemental energy spectra of high-energy cosmic rays in the region up to 10(exp 15) eV. The proposed instrument involves the combination of a large collecting area (approximately 1 x 1 square m) KLEM (Kinematic Lightweight Energy Meter) device with an ionization calorimeter having a smaller collecting area (approximately 0.5 x 0.5 square m) and integrated beneath the KLEM apparatus. This combination has several important advantages. Due to the large aperture (greater than 2 square m sr) of the KLEM device a large exposure factor can be achieved with a long duration balloon flight (2-4 weeks). The calorimeter will collect about 10% of the events already registered by KLEM and provide effective cross-calibration for both energy measurement methods. Details of the experiment and its astrophysical significance will be presented.

  15. IceCube: Particle Astrophysics with High Energy Neutrinos

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Monday 7 May 2012 17h. - Ecole de Physique, Auditoire Stueckelberg IceCube: Particle Astrophysics with High Energy Neutrinos Prof. Francis Halzen / University of Wisconsin, Madison Construction and commissioning of the cubic-kilometer IceCube neutrino detector and its low energy extension DeepCore have been completed. The instrument detects neutrinos over a wide energy range: from 10 GeV atmospheric neutrinos to 1010 GeV cosmogenic neutrinos. We will discuss initial results based on a subsample of the ~100,000 neutrino events recorded during construction. We will emphasize the first measurement of the high-energy atmospheric neutrino spectrum, the search for the still enigmatic sources of the Galactic and extragalactic cosmic rays and for the particle nature of dark matter. Une ve...

  16. Research in Neutrino Physics and Particle Astrophysics: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Kearns, Edward [Boston Univ., MA (United States)

    2016-06-30

    The Boston University Neutrino Physics and Particle Astrophysics Group investigates the fundamental laws of particle physics using natural and man-made neutrinos and rare processes such as proton decay. The primary instrument for this research is the massive Super-Kamiokande (SK) water Cherenkov detector, operating since 1996 at the Kamioka Neutrino Observatory, one kilometer underground in a mine in Japan. We study atmospheric neutrinos from cosmic rays, which were first used to discover that neutrinos have mass, as recognized by the 2015 Nobel Prize in Physics. Our latest measurements with atmospheric neutrinos are giving valuable information, complementary to longbaseline experiments, on the ordering of massive neutrino states and as to whether neutrinos violate CP symmetry. We have studied a variety of proton decay modes, including the most frequently predicted modes such as p → e+π0 and p → ν K+, as well as more exotic baryon number violating processes such as dinucleon decay and neutronantineutron oscillation. We search for neutrinos from dark matter annihilation or decay in the universe. Our group has made significant contributions to detector operation, particularly in the area of electronics. Most recently, we have contributed to planning for an upgrade to the SK detector by the addition of gadolinium to the water, which will enable efficient neutron capture detection.

  17. Landscape of Future Accelerators at the Energy and Intensity Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M. J. [Northern Illinois U.; Chattopadhyay, S. [Northern Illinois U.

    2016-11-21

    An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

  18. Frontier Assignment for Sensitivity Analysis of Data Envelopment Analysis

    Science.gov (United States)

    Naito, Akio; Aoki, Shingo; Tsuji, Hiroshi

    To extend the sensitivity analysis capability for DEA (Data Envelopment Analysis), this paper proposes frontier assignment based DEA (FA-DEA). The basic idea of FA-DEA is to allow a decision maker to decide frontier intentionally while the traditional DEA and Super-DEA decide frontier computationally. The features of FA-DEA are as follows: (1) provides chances to exclude extra-influential DMU (Decision Making Unit) and finds extra-ordinal DMU, and (2) includes the function of the traditional DEA and Super-DEA so that it is able to deal with sensitivity analysis more flexibly. Simple numerical study has shown the effectiveness of the proposed FA-DEA and the difference from the traditional DEA.

  19. General Astrophysics Science Enabled by the HabEx Ultraviolet Spectrograph (UVS)

    Science.gov (United States)

    Scowen, Paul; Clarke, John; Gaudi, B. Scott; Kiessling, Alina; Martin, Stefan; Somerville, Rachel; Stern, Daniel; HabEx Science and Technology Definition Team

    2018-01-01

    The Habitable Exoplanet Imaging Mission (HabEx) is one of the four large mission concepts being studied by NASA as input to the upcoming 2020 Decadal Survey. The mission implements two world-class General Astrophysics instruments as part of its complement of instrumentation to enable compelling science using the 4m aperture. The Ultraviolet Spectrograph has been designed to address cutting edge far ultraviolet (FUV) science that has not been possible with the Hubble Space Telescope, and to open up a wide range of capabilities that will advance astrophysics as we look into the 2030s. Our poster discusses some of those science drivers and possible applications, which range from Solar System science, to nearby and more distant studies of star formation, to studies of the circumgalactic and intergalactic mediums where the ecology of mass and energy transfer are vital to understanding stellar and galactic evolution. We discuss the performance features of the instrument that include a large 3’x3’ field of view for multi-object spectroscopy, and some 20 grating modes for a variety of spectral resolution and coverage.

  20. Refresher Course on Frontier in Atomospheric Sciences

    Indian Academy of Sciences (India)

    Admin

    This course will include lectures by eminent scientists and visits to the state-of-art computer and instrumentation facilities. It will provide an excellent opportunity to get an insight into the latest developments and modern outlook of atmospheric science for students who plan to make their careers in atmospheric sciences or for ...