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Sample records for physics astrophysics geophysics

  1. Nuclear physics and astrophysics

    SciTech Connect

    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.

  2. Celebrating the physics in geophysics

    NASA Astrophysics Data System (ADS)

    Davis, Anthony B.; Sornette, Didier

    The United Nations' Educational, Scientific and Cultural Organization (UNESCO) declared 2005 the “World Year of Physics” in celebration of the centennial of Einstein's annus mirabilis when, as junior clerk at the Swiss Patent Office in Berne, he published three papers that changed physics forever by (1) introducing Special Relativity and demonstrating the equivalence of mass and energy (E = mc2), (2) explaining the photoelectric effect with Planck's then-still-new-and-controversial concept of light quanta (E = hv), and (3) investigating the macroscopic phenomenon of Brownian motion using Boltzmann's molecular dynamics (E = kT), still far from fully accepted at the time.The celebration of Einstein's work in physics inspires the reflection on the status of geophysics and its relationship with physics, in particular with respect to great discoveries.

  3. PREFACE: Nuclear Physics in Astrophysics III

    NASA Astrophysics Data System (ADS)

    Bemmerer, D.; Grosse, E.; Junghans, A. R.; Schwengner, R.; Wagner, A.

    2008-01-01

    The Europhysics Conference `Nuclear Physics in Astrophysics III' (NPA3) took place from 26 31 March 2007 in Dresden, Germany, hosted by Forschungszentrum Dresden-Rossendorf. The present special issue of Journal of Physics G: Nuclear and Particle Physics contains all peer-reviewed contributions to the proceedings of this conference. NPA3 is the third conference in the Nuclear Physics in Astrophysics series of conferences devoted to the interplay between nuclear physics and astrophysics. The first and second editions of the series were held in 2002 and 2005 in Debrecen, Hungary. NPA3 has been organized under the auspices of the Nuclear Physics Board of the European Physical Society as its XXI Divisional Conference. The conference marks the 50th anniversary of the landmark paper B2FH published in 1957 by E M Burbidge, G R Burbidge, W A Fowler and F Hoyle. A public lecture by Claus Rolfs (Ruhr-Universität Bochum, Germany) commemorated the progress achieved since 1957. NPA3 aimed to bring together experimental and theoretical nuclear physicists, astrophysicists and astronomers to address the important part played by nuclear physics in current astrophysical problems. A total of 130 participants from 71 institutions in 26 countries attended the conference, presenting 33 invited and 38 contributed talks and 25 posters on six subject areas. The astrophysical motivation and the nuclear tools employed to address it are highlighted by the titles of the subject areas: Big Bang Nucleosynthesis Stellar Nucleosynthesis and Low Cross Section Measurement Explosive Nucleosynthesis and Nuclear Astrophysics with Photons Nuclei far from Stability and Radioactive Ion Beams Dense Matter in Neutron Stars and Relativistic Nuclear Collisions Neutrinos in Nuclear Astrophysics The presentations and discussions proved that Nuclear Astrophysics is a truly interdisciplinary subject. The remarkable progress in astronomical observations achieved in recent years is matched by advances in

  4. Astrophysical probes of fundamental physics

    NASA Astrophysics Data System (ADS)

    Martins, C. J. A. P.

    2009-10-01

    I review the motivation for varying fundamental couplings and discuss how these measurements can be used to constrain fundamental physics scenarios that would otherwise be inaccessible to experiment. I highlight the current controversial evidence for varying couplings and present some new results. Finally I focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements might be used to probe the nature of dark energy, with some advantages over standard methods. In particular I discuss what can be achieved with future spectrographs such as ESPRESSO and CODEX.

  5. Astrophysical Probes of Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Martins, C. J. A. P.

    I review the theoretical motivation for varying fundamental couplings and discuss how these measurements can be used to constrain a number of fundamental physics scenarios that would otherwise be inacessible to experiment. As a case study I will focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements can be used to probe the nature of dark energy, with important advantages over the standard methods. Assuming that the current observational evidence for varying α. and μ is correct, a several-sigma detection of dynamical dark energy is feasible within a few years, using currently operational ground-based facilities. With forthcoming instruments like CODEX, a high-accuracy reconstruction of the equation of state may be possible all the way up to redshift z ˜ 4.

  6. Plasma physics of extreme astrophysical environments

    NASA Astrophysics Data System (ADS)

    Uzdensky, Dmitri A.; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)—the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  7. Plasma physics of extreme astrophysical environments.

    PubMed

    Uzdensky, Dmitri A; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)--the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  8. Physics, Astrophysics and Cosmology with Gravitational Waves.

    PubMed

    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.

  9. FOREWORD: Nuclear Physics in Astrophysics V

    NASA Astrophysics Data System (ADS)

    Auerbach, Naftali; Hass, Michael; Paul, Michael

    2012-02-01

    The fifth edition of the bi-annual 'Nuclear Physics in Astrophysics (NPA)' conference series was held in Eilat, Israel on April 3-8, 2011. This Conference is also designated as the 24th Nuclear Physics Divisional Conference of the EPS. The main purpose of this conference, as that of the four previous ones in this series, is to deal with those aspects of nuclear physics that are directly related to astrophysics. The concept of such a meeting was conceived by the Nuclear Physics Board of the European Physical Society in 1998. At that time, the idea of such a conference was quite new and it was decided that this meeting would be sponsored by the EPS. The first meeting, in January 2001, was planned and organized in Eilat, Israel. Due to international circumstances the conference was moved to Debrecen, Hungary. Subsequent conferences were held in Debrecen again, in Dresden, Germany, and in Frascati, Italy (moved from Gran Sasso due to the tragic earthquake that hit the L'Aquila region). After 10 years the conference finally returned to Eilat, the originally envisioned site. Eilat is a resort town located on the shore of the Gulf of Eilat, which connects Israel to the Red Sea and further south to the Indian Ocean. It commands spectacular views of the desert and mountains, offering unique touristic attractions. The local scientific backdrop of the conference is the fact that the Israeli scientific scene exhibits a wide variety of research activities in many areas of nuclear physics and astrophysics. A new accelerator, SARAF at Soreq Nuclear Research Center is presently undergoing final acceptance tests. SARAF will serve as a platform for production of radioactive ion beams and nuclear-astrophysics research in Israel. The meeting in Eilat was organized by four Israeli scientific institutions, Hebrew University, Soreq Nuclear Research Center, Tel Aviv University and the Weizmann Institute of Science. The welcome reception and lectures were held at the King Solomon hotel and

  10. GeoPhysical Analysis Code

    SciTech Connect

    2011-05-21

    GPAC is a code that integrates open source libraries for element formulations, linear algebra, and I/O with two main LLNL-Written components: (i) a set of standard finite elements physics solvers for rersolving Darcy fluid flow, explicit mechanics, implicit mechanics, and fluid-mediated fracturing, including resolution of contact both implicity and explicity, and (ii) a MPI-based parallelization implementation for use on generic HPC distributed memory architectures. The resultant code can be used alone for linearly elastic problems and problems involving hydraulic fracturing, where the mesh topology is dynamically changed. The key application domain is for low-rate stimulation and fracture control in subsurface reservoirs (e.g., enhanced geothermal sites and unconventional shale gas stimulation). GPAC also has interfaces to call external libraries for, e.g., material models and equations of state; however, LLNL-developed EOS and material models will not be part of the current release.

  11. GeoPhysical Analysis Code

    SciTech Connect

    2012-12-21

    GPAC is a code that integrates open source libraries for element formulations, linear algebra, and I/O with two main LLNL-written components: (i) a set of standard finite, discrete, and discontinuous displacement element physics solvers for resolving Darcy fluid flow, explicit mechanics, implicit mechanics, fault rupture and earthquake nucleation, and fluid-mediated fracturing, including resolution of physcial behaviors both implicity and explicity, and (ii) a MPI-based parallelization implementation for use on generic HPC distributed memory architectures. The resultant code can be used alone for linearly elastic problems; ploblems involving hydraulic fracturing, where the mesh topology is dynamically changed; fault rupture modeling and seismic risk assessment; and general granular materials behavior. The key application domain is for low-rate stimulation and fracture control in subsurface reservoirs (e.g., enhanced geothermal sites and unconventional shale gas stimulation). GPAC also has interfaces to call external libraries for , e.g., material models and equations of state; however, LLNL-developed EOS and material models will not be part of the current release. CPAC's secondary applications include modeling fault evolution for predicting the statistical distribution of earthquake events and to capture granular materials behavior under different load paths.

  12. BOOK REVIEW: Astrophysics (Advanced Physics Readers)

    NASA Astrophysics Data System (ADS)

    Kibble, Bob

    2000-07-01

    Here is a handy and attractive reader to support students on post-16 courses. It covers the astrophysics, astronomy and cosmology that are demanded at A-level and offers anyone interested in these fields an interesting and engaging reference book. The author and the production team deserve credit for producing such an attractive book. The content, in ten chapters, covers what one would expect at this level but it is how it is presented that struck me as the book's most powerful asset. Each chapter ends with a summary of key ideas. Line drawings are clear and convey enough information to make them more than illustrations - they are as valuable as the text in conveying information. Full colour is used throughout to enhance illustrations and tables and to lift key sections of the text. A number of colour photographs complement the material and serve to maintain interest and remind readers that astrophysics is about real observable phenomena. Included towards the end is a set of tables offering information on physical and astronomical data, mathematical techniques and constellation names and abbreviations. This last table puzzled me as to its value. There is a helpful bibliography which includes society contacts and a website related to the text. Perhaps my one regret is that there is no section where students are encouraged to actually do some real astronomy. Astrophysics is in danger of becoming an armchair and calculator interest. There are practical projects that students could undertake either for school assessment or for personal interest. Simple astrophotography to capture star trails, observe star colours and estimate apparent magnitudes is an example, as is a simple double-star search. There are dozens more. However, the author's style is friendly and collaborative. He befriends the reader as they journey together through the ideas. There are progress questions at the end of each chapter. Their style tends to be rather closed and they emphasize factual recall

  13. Computing Across the Physics and Astrophysics Curriculum

    NASA Astrophysics Data System (ADS)

    DeGioia Eastwood, Kathy; James, M.; Dolle, E.

    2012-01-01

    Computational skills are essential in today's marketplace. Bachelors entering the STEM workforce report that their undergraduate education does not adequately prepare them to use scientific software and to write programs. Computation can also increase student learning; not only are the students actively engaged, but computational problems allow them to explore physical problems that are more realistic than the few that can be solved analytically. We have received a grant from the NSF CCLI Phase I program to integrate computing into our upper division curriculum. Our language of choice is Matlab; this language had already been chosen for our required sophomore course in Computational Physics because of its prevalence in industry. For two summers we have held faculty workshops to help our professors develop the needed expertise, and we are now in the implementation and evaluation stage. The end product will be a set of learning materials in the form of computational modules that we will make freely available. These modules will include the assignment, pedagogical goals, Matlab code, samples of student work, and instructor comments. At this meeting we present an overview of the project as well as modules written for a course in upper division stellar astrophysics. We acknowledge the support of the NSF through DUE-0837368.

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

    SciTech Connect

    Arcones, Almudena; Escher, Jutta E.; Others, M.

    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.

  15. Investigations in γ-Ray Astrophysics and Astroparticle Physics

    SciTech Connect

    Krennrich, Frank

    2016-06-28

    This report describes the status of data analysis efforts, results and publications of research grant DE-SC0009917. The research is focused on TeV gamma-ray studies of astrophysical sources and related particle physics questions.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Constraining Unparticle Physics with Cosmology and Astrophysics

    SciTech Connect

    Davoudiasl, Hooman

    2007-10-05

    It has recently been suggested that a scale-invariant 'unparticle' sector with a nontrivial infrared fixed point may couple to the standard model (SM) via higher-dimensional operators. The weakness of such interactions hides the unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on the strength of unparticle-SM interactions. We also discuss the possibility of a having a non-negligible unparticle relic density today.

  18. Constraining unparticle physics with cosmology and astrophysics.

    PubMed

    Davoudiasl, Hooman

    2007-10-05

    It has recently been suggested that a scale-invariant "unparticle" sector with a nontrivial infrared fixed point may couple to the standard model (SM) via higher-dimensional operators. The weakness of such interactions hides the unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on the strength of unparticle-SM interactions. We also discuss the possibility of a having a non-negligible unparticle relic density today.

  19. MFGA-IDT2 workshop: Astrophysical and geophysical fluid mechanics: the impact of data on turbulence theories

    NASA Astrophysics Data System (ADS)

    Schertzer, D.; Falgarone, E.

    1 Facts about the Workshop This workshop was convened on November 13-15 1995 by E. Falgarone and D. Schertzer within the framework of the Groupe de Recherche Mecanique des Fluides Geophysiques et Astrophysiques (GdR MFGA, Research Group of Geophysical and Astrophysical Fluid Mechanics) of Centre National de la Recherche Scientifique (CNRS, (French) National Center for Scientific Research). This Research Group is chaired by A. Babiano and the meeting was held at Ecole Normale Superieure, Paris, by courtesy of its Director E. Guyon. More than sixty attendees participated to this workshop, they came from a large number of institutions and countries from Europe, Canada and USA. There were twenty-five oral presentations as well as a dozen posters. A copy of the corresponding book of abstracts can be requested to the conveners. The theme of this meeting is somewhat related to the series of Nonlinear Variability in Geophysics conferences (NVAG1, Montreal, Aug. 1986; NVAG2, Paris, June 1988; NVAG3, Cargese (Corsica), September, 1993), as well as seven consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions devoted to similar topics. One may note that NVAG3 was a joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first topical conference jointly sponsored by the two organizations. The corresponding proceedings were published in a special NPG issue (Nonlinear Processes in Geophysics 1, 2/3, 1994). In comparison with these previous meetings, MFGA-IDT2 is at the same time specialized to fluid turbulence and its intermittency, and an extension to the fields of astrophysics. Let us add that Nonlinear Processes in Geophysics was readily chosen as the appropriate journal for publication of these proceedings since this journal was founded in order to develop interdisciplinary fundamental research and corresponding innovative nonlinear methodologies in Geophysics. It had an

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

    DOE PAGES

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; ...

    2016-12-28

    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, 2012more » 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.« less

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

    SciTech Connect

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; Bernstein, 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; Escher, Jutta E.; Fields, Brian D.; Fröhlich, Carla; Herwig, Falk; Hix, William Raphael; Iliadis, Christian; Lynch, William G.; McLaughlin, Gail C.; Meyer, Bradley S.; Mezzacappa, Anthony; Nunes, Filomena; O’Shea, Brian W.; Prakash, Madappa; Pritychenko, Boris; Reddy, Sanjay; Rehm, Ernst; Rogachev, Grigory; Rutledge, Robert E.; Schatz, Hendrik; Smith, Michael S.; Stairs, Ingrid H.; Steiner, Andrew W.; Strohmayer, Tod E.; Townsley, Dean M.; Wiescher, Michael; Zegers, Remco G. T.; Zingale, Michael

    2016-12-28

    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.

  2. Cosmic rays: Physics and astrophysics. A research briefing

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Some recent results in cosmic-ray physics are summarized, and how they raise new questions of interest for both physics and astrophysics is described. An important technical advance, the recently demonstrated capability of long-duration balloon flights of heavy payloads, will offer a great advantage for achieving some of these goals.

  3. PREFACE: Nuclear Physics in Astrophysics VI (NPA6)

    NASA Astrophysics Data System (ADS)

    2016-01-01

    The Nuclear Physics in Astrophysics VI conference was the 6th event of the NPA biannual conference series. Previous events of this series were held at the Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary, in 2002 and 2005; at the Forschungszentrum Dresden-Rossendorf, Dresden, Germany, in 2007; at the Laboratori Nazionali del Gran Sasso (LNGS), L'Aquila, Italy, in 2009; and in Eilat, Israel, in 2011. This edition of the NPA conference series was organized by the European Physical Society (EPS) through its Nuclear Physics Division, corresponding to the 26th edition of the Topical Conferences of the EPS. As in previous editions, the goal of the NPA conference was to bring together the specialists in the fields of Nuclear Physics (theory and experiment) and Nuclear Astrophysics (theory and observation), providing the appropriate forum for review and discussion of the status and prospects of the field of Nuclear Astrophysics. During the discussions, special attention was given to the Nuclear Physics aspects that have an impact in Astrophysics.

  4. Nuclear and particle physics, astrophysics and cosmology (NPAC) capability review

    SciTech Connect

    Redondo, Antonio

    2010-01-01

    The present document represents a summary self-assessment of the status of the Nuclear and Particle Physics, Astrophysics and Cosmology (NPAC) capability across Los Alamos National Laboratory (LANL). For the purpose of this review, we have divided the capability into four theme areas: Nuclear Physics, Particle Physics, Astrophysics and Cosmology, and Applied Physics. For each theme area we have given a general but brief description of the activities under the area, a list of the Laboratory divisions involved in the work, connections to the goals and mission of the Laboratory, a brief description of progress over the last three years, our opinion of the overall status of the theme area, and challenges and issues.

  5. PREFACE: International Conference on Particle Physics and Astrophysics (ICPPA-2015)

    NASA Astrophysics Data System (ADS)

    2016-02-01

    The International Conference on Particle Physics and Astrophysics (ICPPA-2015) was held in Moscow, Russia, from October 5 to 10, 2015. The conference is organized by Center of Fundamental 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. We bring together experts and young scientists working on experimental and theoretical aspects of nuclear, particle, astroparticle physics and cosmology. The conference covers a wide range of topics such as accelerator physics, (astro) particle physics, cosmic rays, cosmology and methods of experimental physics - detectors and instruments. These directions are unified by development of the Standard Model (SM) which is evidently not complete. There are deviations from the Standard Model - neutrino oscillations, the dark matter existence. Together with strong interactions, they are main subjects of the Conference. New results from LHC collider as well as its future upgrade are discussed with the Higgs as the main point for discussion. Substantial development of experimental tools for astrophysical observations and new results from cosmic ray experiments is one of the main subjects of the conference. Various aspects of strong interaction are discussed. Among them: Charmonium and Bottomonium states, Flavor physics at Super B factories, Exotic Nuclei in Astrophysics. Another subject for discussion is the neutrino physics, promising and unique way to get new knowledge. In this content, several talks on BOREXINO experiment where new results in neutrino oscillations are presented. Special session is devoted to PAMELA experiment - 9 years in orbit and to the future GAMMA-400 gamma-ray telescope with following main scientific goals: indirect dark matter origin study by the gamma-ray astronomy methods, discrete astrophysical sources observations, diffuse background γ-emission analysis

  6. Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, 1996 Annual Report

    SciTech Connect

    Ryerson, F. J., Institute of Geophysics and Planetary Physics

    1998-03-23

    The Institute of Geophysics and Planetary Physics (IGPP) is a Multicampus Research Unit of the University of California (UC). IGPP was founded in 1946 at UC Los Angeles with a charter to further research in the earth and planetary sciences and in related fields. The Institute now has branches at UC campuses in Los Angeles, San Diego, and Riverside, and at Los Alamos and Lawrence Livermore national laboratories. The University-wide IGPP has played an important role in establishing interdisciplinary research in the earth and planetary sciences. For example, IGPP was instrumental in founding the fields of physical oceanography and space physics, which at the time fell between the cracks of established university departments. Because of its multicampus orientation, IGPP has sponsored important interinstitutional consortia in the earth and planetary sciences. Each of the five branches has a somewhat different intellectual emphasis as a result of the interplay between strengths of campus departments and Laboratory programs. The IGPP branch at Lawrence Livermore National Laboratory (LLNL) was approved by the Regents of the University of California in 1982. IGPP-LLNL emphasizes research in seismology, geochemistry, cosmochemistry, and astrophysics. It provides a venue for studying the fundamental aspects of these fields, thereby complementing LLNL programs that pursue applications of these disciplines in national security and energy research. IGPP-LLNL is directed by Charles Alcock and was originally organized into three centers: Geosciences, stressing seismology; High-Pressure Physics, stressing experiments using the two-stage light-gas gun at LLNL; and Astrophysics, stressing theoretical and computational astrophysics. In 1994, the activities of the Center for High-Pressure Physics were merged with those of the Center for Geosciences. The Center for Geosciences, headed by Frederick Ryerson, focuses on research in geophysics and geochemistry. The Astrophysics Research

  7. Basic Physics Questions Addressed by Astrophysics

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2009-01-01

    Dark matter, dark energy, the Big Bang, testing relativity -- all are physics questions accessible to astrophysicists -- but all require new equipment. As Harwit's "Cosmic Discovery" pointed out, almost all great surprises in astronomy came from new equipment or new uses of equipment designed for other purposes, and many of those had military applications. I will outline prospects for new equipment and discuss how that equipment can be developed and built. Bigger and lighter mirrors, wavefront sensing and control, new detector technology, cryogenics -- each has its own social network, its own special possibilities, and its own funding sources outside science. I will discuss some examples drawn from real-life experience with the James Webb Space Telescope, a telescope that was said to have a "giggle factor" when it was proposed in 1995. Now each of the 10 major technologies has been brought to maturity, flight hardware is being built, and launch is planned for 2014. As an instrument builder all my life, I will speculate a little on what may be within our reach over the next few decades.

  8. Implications of Ultrahigh Energy Air Showers for Physics and Astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The primary ultrahigh energy particles which produce giant extensive air showers in the Earth atmosphere present an intriguing mystery from two points of view: (1) How are the base particles produced with such astounding energies, eight orders of magnitude higher than those produced by the best man-made terrestrial accelerators? (2) Since they are most likely extragalactic in origin, how do they reach us from extragalactic distances without suffering the severe losses expected from interactions with the 2.7 K thermal cosmic background photons, the so called GZK effect? The answers to these questions may involve new physics: violations of special relativity, grand unification theories, and quantum gravity theories involving large extra dimensions. They may involve new astrophysical sources, "zevatrons". Or some heretofore totally unknown physics or astrophysics may hold the answer. I will discuss here the mysteries involving the production and extragalactic propagation of ultrahigh energy cosmic rays and some suggested possible solutions.

  9. Radiative decay of massious neutrinos: Implications for physics and astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1981-01-01

    The radiative lifetime tau for the decay of massious neutrinos is calculated using various physical models for neutrino decay. The results are related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data are used to place lower limits on tau. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models. It is considered that this may be an important test for substructure in leptons and quarks.

  10. Effect of New Physics in Astrophysical Neutrino Flavor.

    PubMed

    Argüelles, Carlos A; Katori, Teppei; Salvado, Jordi

    2015-10-16

    Astrophysical neutrinos are powerful tools for investigating the fundamental properties of particle physics through their flavor content. In this Letter, we perform the first general new physics study on ultrahigh energy neutrino flavor content by introducing effective operators. We find that, at the current limits on these operators, new physics terms cause maximal effects on the flavor content; however, the flavor content on the Earth is confined to a region related to the assumed initial flavor content. Furthermore, we conclude that a precise measure of the flavor content on the Earth will provide orders of magnitude improvement on new physics bounds. Finally, we discuss the current best fits of flavor content of the IceCube data and their interplay with new physics scenarios.

  11. Institute of Geophysics and Planetary Physics at Lawrence Livermore National Laboratory: 1986 annual report

    SciTech Connect

    Max, C.E.

    1987-07-01

    The purpose of the Institute of Geophysics and Planetary Physics (IGPP) at LLNL is to enrich the opportunities of University of California campus researchers by making available to them some of the Laboratory's unique facilities and expertise, and to broaden the scientific horizon of LLNL researchers by encouraging collaborative or interdisciplinary work with other UC scientists. The IGPP continues to emphasize three fields of research - geoscience, astrophysics, and high-pressure physics - each administered by a corresponding IGPP Research Center. Each Research Center coordinates the mini-grant work in its field, and also works with the appropriate LLNL programs and departments, which frequently can provide supplementary funding and facilities for IGPP projects. 62 refs., 18 figs., 2 tabs.

  12. Liquid xenon detectors for particle physics and astrophysics

    SciTech Connect

    Aprile, E.; Doke, T.

    2010-07-15

    This article reviews the progress made over the last 20 years in the development and applications of liquid xenon detectors in particle physics, astrophysics, and medical imaging experiments. A summary of the fundamental properties of liquid xenon as radiation detection medium, in light of the most current theoretical and experimental information is first provided. After an introduction of the different type of liquid xenon detectors, a review of past, current, and future experiments using liquid xenon to search for rare processes and to image radiation in space and in medicine is given. Each application is introduced with a survey of the underlying scientific motivation and experimental requirements before reviewing the basic characteristics and expected performance of each experiment. Within this decade it appears likely that large volume liquid xenon detectors operated in different modes will contribute to answering some of the most fundamental questions in particle physics, astrophysics, and cosmology, fulfilling the most demanding detection challenges. From detectors based solely on liquid xenon (LXe) scintillation, such as in the MEG experiment for the search of the rare ''{mu}{yields}e{gamma}'' decay, currently the largest liquid xenon detector in operation, and in the XMASS experiment for dark matter detection, to the class of time projection chambers which exploit both scintillation and ionization of LXe, such as in the XENON dark matter search experiment and in the Enriched Xenon Observatory for neutrinoless double beta decay, unrivaled performance and important contributions to physics in the next few years are anticipated.

  13. High-Energy-Density Physics, with Applications to Astrophysics*

    NASA Astrophysics Data System (ADS)

    Remington, Bruce A.

    2002-04-01

    High-energy-density (HED) physics broadly refers to the study of collections of matter under extreme conditions of pressure, temperature, and density. The experimental facilities used for these studies are high power lasers, magnetic pinch generators, and charged particle beams. The HED physics pursued on these facilities is still in its infancy, yet a broad user community has nucleated, and new regimes of experimental science are emerging. [1, 2] Examples drawn from astrophysics include work relevant to supernovae and supernova remnants, astrophysical jets, radiatively driven molecular clouds, accreting black holes, planetary interiors, and gamma-ray bursts. A selection of science highlights in this field from the past decade will be reviewed, and a look ahead to the coming decade will be given. *This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48. 1. B.A. Remington, D. Arnett, R.P. Drake, and H. Takabe, Science 284, 1488 (1999); Phys. Plasmas 7, 1641 (2000). 2. Hideaki Takabe, Prog. Theor. Phys. Suppl. 143, 202 (2001).

  14. Astrophysical Orientation of Physics Students through Seminars in Rural Mexico

    NASA Astrophysics Data System (ADS)

    Chatterjee, T. K.; Vera, D.; Fourier, R.; Pedroza, A.

    In a developing country, science teaching is oriented towards subjects having a bearing on national utility and development of technological skills; thus it is necessary to justify astronomy education. This is conveniently done by introducing an astrophysically oriented course for physics students and connecting it with a sanctioned astronomical project. We have done this at the Faculty and Institute of Science of the Puebla University. This university, in collaboration with other universities and institutes has a (sanctioned) satellite program --SATEX.I (whose objective is to launch communication satellites for data relay in the UHF band and experiment in the K-alpha band). The students of this project (from our university) were in urgent need of a course on "Astrodynamics" and so we opened one; but we invited students (with appropriate knowledge of physics and mathematics) from the entire science faculty, and extended the scope of the course to introduce astrophysical concepts to science students. We also prepared a series of very comprehensive introductory lecture notes, computer-printed them and distributed them (free) amongst students. We have been successful in getting a substantial number of very good students.

  15. Physics and astrophysics with gamma-ray telescopes

    NASA Astrophysics Data System (ADS)

    Vandenbroucke, J.; Fermi LAT Collaboration

    2012-08-01

    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 ˜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 ˜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.

  16. Geophysics

    NASA Technical Reports Server (NTRS)

    Carr, M. H.; Cassen, P.

    1976-01-01

    Four areas of investigation, each dealing with the measurement of a particular geophysical property, are discussed. These properties are the gravity field, seismicity, magnetism, and heat flow. All are strongly affected by conditions, past or present, in the planetary interior; their measurement is the primary source of information about planetary interiors.

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

    SciTech Connect

    Kearns, Edward

    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.

  18. Introduction of Special Physics Topics (Geophysics) Through the Use of Physics Laboratory Projects

    ERIC Educational Resources Information Center

    Parker, R. H.; Whittles, A. B. L.

    1970-01-01

    Describes the objectives and content of a physics laboratory program for freshman students at the British Columbia Institute of Technology. The first part of the program consists of basic physics experiments, while the second part emphasizes student work on projects in geophysics that have direct technical applications. (LC)

  19. Premelting, Snowballs and Climate Change: the ice Physics in Geophysics

    NASA Astrophysics Data System (ADS)

    Wettlaufer, J. S.; Rempel, A. W.; Worster, M. G.

    2001-12-01

    A basic question in the theory of surface phase transitions is ``How does a crystalline solid melt?'' Although we can date the scientific study of phase transitions to at least calcolithic times, today we still rely almost exclusively on empirical descriptions of melting phenomena. For practical reasons much of what we know today has been driven by studying the properties of surfaces, but in the process much has been assumed about the behavior of bulk solids. When we pursue the answer to this fundamental question in the context of ice, we find that a microscopic understanding has a plethora of geophysical implications. Recent advances show that the microscopic interfacial structure of ice is central to pattern formation during ice crystal growth, the adhesion of ice, the evolution of the polycrystalline fabrics of the glaciers, and the underlying dynamics of frost heave. Current research focuses on, in part, consequences of microphysics in the scavenging of atmospheric pollutants by snow, the role of stratospheric ice in ozone destruction, the mechanism of charge transfer driving thunderstorm electrification, the effects of frost heave on engineered structures, and natural ice sheets. This talk describes our emerging understanding of the materials physics of ice, its implications for the basic principles of melting, and several of their geophysical consequences.

  20. Multiple Discipline science assessment. [considering astronomy, astrophysics, cosmology, gravitation and geophysics when planning planetary missions

    NASA Technical Reports Server (NTRS)

    Wells, W. C.

    1978-01-01

    Various science disciplines were examined to determine where and when it is appropriate to include their objectives in the planning of planetary missions. The disciplines considered are solar astronomy, stellar and galactic astronomy, solar physics, cosmology and gravitational physics, the geosciences and the applied sciences. For each discipline, science objectives are identified which could provide a multiple discipline opportunity utilizing either a single spacecraft or two spacecraft delivered by a single launch vehicle. Opportunities using a common engineering system are also considered. The most promising opportunities identified include observations of solar images and relativistic effects using the Mercury orbiter; collection of samples exposed to solar radiation using the Mars surface sample return; studies of interstellar neutral H and He, magnetic fields, cosmic rays, and solar physics during Pluto or Neptune flybys; using the Mars orbiter to obtain solar images from 0.2 AU synchronous or from 90 deg orbit; and the study of the structure and composition of the atmosphere using atmospheric probes and remotely piloted vehicles.

  1. Geophysical and fluid dynamical analyses in physical volcanology

    NASA Astrophysics Data System (ADS)

    Rogers, Patricia Grizzaffi

    Volcanism is a predominant process on the terrestrial planets, and studies of physical volcanologic processes provide fundamental insight into the evolution of a planet's surface and interior. This work combines theoretical modeling, field observations, and studies of planetary surfaces in an integrated approach to understanding the mechanical and dynamic processes associated with volcanism. By understanding the basic dynamics associated with terrestrial volcanic processes, we hope to better understand the evolution of other planetary surfaces for which only remote sensing data are available. The focus of this work is the physics of volcanism in space and time, with an emphasis on regions that are dominated by volcanism such as the Hawaiian islands, and on studies of lava flow emplacement. Applying our knowledge of volcanic processes on Earth to studies of Venusian geology and geophysics is also important for this investigation because volcanism has been a primary process in creating and modifying landforms on that planet. This analysis of geophysical and fluid dynamic processes associated with physical volcanology first focuses on the relationship between volcanic and tectonic processes and the associated stress environments. Specifically, through analytical modeling we investigate the regional stresses associated with Bell Regio, a volcanic highland on Venus, and structural features believed to be a consequence of lithospheric flexure due to volcanic loading. The relationship between the tectonic features surrounding a volcanic edifice and stresses associated with magma chamber inflation are also examined through finite element analysis. The implications of a change in volcanic style and lithospheric thickness over time are discussed. Next, factors that affect the dynamics of lava flow emplacement are examined through a combination ot theoretical modeling and field measurements. Downflow changes in rheology and lava channel formation under conditions of varying

  2. Research in cosmic and gamma ray astrophysics: Cosmic physics portion

    NASA Technical Reports Server (NTRS)

    Stone, Edward C.; Mewaldt, Richard A.; Schindler, Stephen

    1993-01-01

    Research in particle astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology is supported under NASA Grant NAGW-1919. A three-year proposal for continuation of support was submitted a year ago and put into effect 1 October 1992. This report is the combined progress report and continuation application called for under the Federal Demonstration Project. Gamma-ray Astrophysics at SRL is separately supported under NAGW-1919 and will be separately summarized and proposed. This report will document progress and plans for our particle spectroscopy activities and for related data analysis, calibration, and community service activities. A bibliography and a budget will be attached as appendices. The Caltech SRL research program includes a heavy emphasis on elemental and isotopic spectroscopy of energetic particles in the cosmic radiation; in solar, interplanetary, and anomalous 'cosmic' radiation; and in planetary magnetospheres as discussed.

  3. NASA's Physics of the Cosmos and Cosmic Origins programs manage Strategic Astrophysics Technology (SAT) development

    NASA Astrophysics Data System (ADS)

    Pham, Thai; Thronson, Harley; Seery, Bernard; Ganel, Opher

    2016-07-01

    The strategic astrophysics missions of the coming decades will help answer the questions "How did our universe begin and evolve?" "How did galaxies, stars, and planets come to be?" and "Are we alone?" Enabling these missions requires advances in key technologies far beyond the current state of the art. NASA's Physics of the Cosmos2 (PCOS), Cosmic Origins3 (COR), and Exoplanet Exploration Program4 (ExEP) Program Offices manage technology maturation projects funded through the Strategic Astrophysics Technology (SAT) program to accomplish such advances. The PCOS and COR Program Offices, residing at the NASA Goddard Space Flight Center (GSFC), were established in 2011, and serve as the implementation arm for the Astrophysics Division at NASA Headquarters. We present an overview of the Programs' technology development activities and the current technology investment portfolio of 23 technology advancements. We discuss the process for addressing community-provided technology gaps and Technology Management Board (TMB)-vetted prioritization and investment recommendations that inform the SAT program. The process improves the transparency and relevance of our technology investments, provides the community a voice in the process, and promotes targeted external technology investments by defining needs and identifying customers. The Programs' priorities are driven by strategic direction from the Astrophysics Division, which is informed by the National Research Council's (NRC) "New Worlds, New Horizons in Astronomy and Astrophysics" (NWNH) 2010 Decadal Survey report [1], the Astrophysics Implementation Plan (AIP) [2] as updated, and the Astrophysics Roadmap "Enduring Quests, Daring Visions" [3]. These priorities include technology development for missions to study dark energy, gravitational waves, X-ray and inflation probe science, and large far-infrared (IR) and ultraviolet (UV)/optical/IR telescopes to conduct imaging and spectroscopy studies. The SAT program is the

  4. Geophysical, petrological and mineral physics constraints on Earth's surface topography

    NASA Astrophysics Data System (ADS)

    Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

    2015-04-01

    Earth's surface topography is controlled by isostatically compensated density variations within the lithosphere, but dynamic topography - i.e. the topography due to adjustment of surface to mantle convection - is an important component, specially at a global scale. In order to separate these two components it is fundamental to estimate crustal and mantle density structure and rheological properties. Usually, crustal density is constrained from interpretation of available seismic data (mostly VP profiles) based on empirical relationships such those in Brocher [2005]. Mantle density structure is inferred from seismic tomography models. Constant coefficients are used to interpret seismic velocity anomalies in density anomalies. These simplified methods are unable to model the effects that pressure and temperature variations have on mineralogical assemblage and physical properties. Our approach is based on a multidisciplinary method that involves geophysical observables, mineral physics constraints, and petrological data. Mantle density is based on the thermal interpretation of global seismic tomography models assuming various compositional structures, as in Cammarano et al. [2011]. We further constrain the top 150 km by including heat-flow data and considering the thermal evolution of the oceanic lithosphere. Crustal density is calculated as in Guerri and Cammarano [2015] performing thermodynamic modeling of various average chemical compositions proposed for the crust. The modeling, performed with the code PerpleX [Connolly, 2005], relies on the thermodynamic dataset from Holland and Powell [1998]. Compressional waves velocity and crustal layers thickness from the model CRUST 1.0 [Laske et al., 2013] offer additional constrains. The resulting lithospheric density models are tested against gravity (GOCE) data. Various crustal and mantle density models have been tested in order to ascertain the effects that uncertainties in the estimate of those features have on the

  5. Black hole bombs and explosions: from astrophysics to particle physics

    NASA Astrophysics Data System (ADS)

    Cardoso, Vitor

    2013-11-01

    Black holes are the elementary particles of gravity, the final state of sufficiently massive stars and of energetic collisions. With a 40-year long history, black hole physics is a fully-blossomed field which promises to embrace several branches of theoretical physics. Here I review the main developments in highly dynamical black holes with an emphasis on high energy black hole collisions and probes of particle physics via superradiance. This write-up, rather than being a collection of well known results, is intended to highlight open issues and the most intriguing results.

  6. The Signatures of New Physics, Astrophysics and Cosmology?

    NASA Astrophysics Data System (ADS)

    Hajdukovic, Dragan Slavkov

    2013-08-01

    The first three years of the LHC experiments at CERN have ended with "the nightmare scenario": all tests, confirm the Standard Model of Particles so well that theorists must search for new physics without any experimental guidance. The supersymmetric theories, a privileged candidate for new physics, are nearly excluded. As a potential escape from the crisis, we propose thinking about a series of astonishing relations suggesting fundamental interconnections between the quantum world and the large scale Universe. It seems reasonable that, for instance, the equation relating a quark-antiquark pair with the fundamental physical constants and cosmological parameters must be a sign of new physics. One of the intriguing possibilities is interpreting our relations as a signature of the quantum vacuum containing the virtual gravitational dipoles.

  7. Particle Astrophysics and Cosmology: Cosmic Laboratories for New Physics (Summary of the Snowmass 2001 P4 Working Group)

    NASA Technical Reports Server (NTRS)

    Akerib, Daniel S.; Carroll, Sean M.; Kaminokowski, Marc; Ritz, Steven; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The past few years have seen dramatic breakthroughs and spectacular and puzzling discoveries in astrophysics and cosmology. In many cases, the new observations can only be explained with the introduction of new fundamental physics. Here we summarize some of these recent advances. We then describe several problems in astrophysics and cosmology, ripe for major advances, the resolution of which will likely require new physics.

  8. Construction of the Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) at Notre Dame

    NASA Astrophysics Data System (ADS)

    Allen, Jacob; Bardayan, Dan; Blankstein, Drew; Hall, Matthew; Hall, Oscar; Kolata, James; O'Malley, Patrick; Becchetti, Frederick; Blackmon, Jeffery; Pain, Steven

    2016-09-01

    The study of nucleon transfer reactions gives information about many nuclei involved in astrophysical processes. The design and use of new detector systems improves our ability to accurately characterize these nuclei. The Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) is a new helical orbit spectrometer being designed at the University of Notre Dame to study transfer reactions with high-energy light ion beams from the FN tandem accelerator. SSNAP incorporates a series of position-sensitive silicon detectors to be set on-axis inside the second TwinSol solenoid. SSNAP will be sensitive to light ions produced in different reactions and the charged-particle decay products from the exotic nuclei produced. Results of initial testing and future plans with this detector system will be shown in this presentation. This work is supported by the National Science Foundation and the Joint Institute for Nuclear Astrophysics.

  9. Opportunities in cosmic-ray physics and astrophysics

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Board on Physics and Astronomy of the National Research Council established the Committee on Cosmic-Ray Physics to prepare a review of the field that addresses both experimental and theoretical aspects of the origin of cosmic radiation from outside the heliosphere. The following recommendations are made: NASA should provide the opportunity to measure cosmic-ray electrons, positrons, ultraheavy nuclei, isotopes, and antiparticles in space; NASA, the National Science Foundation (NSF), and the Department of Energy (DOE) should facilitate direct and indirect measurement of the elemental composition to as high an energy as possible, for which the support of long-duration ballooning and hybrid ground arrays will be needed; NSF and DOE should support the new Fly's Eye and provide for U.S. participation in the big projects on the horizon, which include giant arrays, ground-based gamma-ray astronomy, and neutrino telescopes; and NASA, NSF, and DOE should support a strong program of relevant theoretical investigations.

  10. Astrophysical tests for radiative decay of neutrinos and fundamental physics implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Brown, R. W.

    1981-01-01

    The radiative lifetime tau for the decay of massious neutrinos was calculated using various physical models for neutrino decay. The results were then related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data were used to place lower limits on tau. These limits are all well below predicted values. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models or other new physics. Thus an important test for substructure in leptons and quarks or other physics beyond the standard electroweak model may have been found.

  11. Visualization techniques and tools for large geo-physical networks

    NASA Astrophysics Data System (ADS)

    Nocke, Thomas; Buschmann, Stefan; Donges, Jonathan F.; Marwan, Norbert

    2016-04-01

    Network analysis is an important approach in studying complex phenomena within geophysical observation and simulation data. This field produces increasing numbers of large geo-referenced networks to be analyzed. Particular focus lies on the network analysis of the complex statistical interrelationship structure within climatological fields. The typical procedure for such network analyzes is the extraction of network measures in combination with static standard visualization methods. To analyze the visualization challenges within this field, we performed a questionnaire with climate and complex system scientists, and identified a strong requirement for solutions visualizing large and very large geo-referenced networks by providing alternative mappings for static plots and allowing for interactive visualization for networks with 100.000 or even millions of edges. In addition, the questionnaire revealed, that existing interactive visualization methods and tools for geo-referenced network exploration are often either not known to the analyst or their potential is not fully exploited. Within this presentation, we illustrate how interactive visual analytics methods in combination with geo-visualisation can be tailored for visual large climate network investigation (see as well Nocke et al. 2015). Therefore, we present a survey of requirements of network analysts and the related challenges and, as an overview for the interested practitioner, we review the state-of-the-art in climate network visualization techniques and tools, underpinned with concrete examples from climate network research and innovative solutions (e.g. alternative projections, 3D layered networks) implemented within the network visualization system GTX. References: Nocke, T., S. Buschmann, J. F. Donges, N. Marwan, H.-J. Schulz, and C. Tominski: Review: Visual analytics of climate networks, Nonlinear Processes in Geophysics, 22, 545-570, doi:10.5194/npg-22-545-2015, 2015

  12. The New Physics and Astronomy Education Portal of the Smithsonian/NASA Astrophysics Data System

    NASA Astrophysics Data System (ADS)

    Kurtz, Michael J.; Eichhorn, G.; Accomazzi, A.; Grant, C.; Henneken, E.; Thompson, D.; Bohlen, E.; Murray, S. S.

    2006-12-01

    The ADS announces the beta release of a new portal into the technical literature for physics and astronomy education. This project is being done in collaboration with ComPADRE. Currently the collection contains about 30,000 articles covering the Science Education literature; key journals in the collection include Research in Science Education, Physical Review Special Topics Physics Education Research, The Physics Teacher, The American Journal of Physics, Physics Education, Journal of Research in Science Teaching, The International Journal of Science Education. Several other journals are also included, including some from nearby fields, such as computer science and chemistry education. The system easily has the ability to include any individual article from the research literature of physics and astronomy (such as from the Physical Review or the Astrophysical Journal) either from current or historical research. We encourage educators to suggest such articles to us. This is the beta release of a new system; we encourage comments, critisms and suggestions.

  13. The Physics of Magnetars and Its Astrophysical Significance

    NASA Astrophysics Data System (ADS)

    Peng, Qiuhe

    2015-08-01

    We present the microscopic origin of the super strong magnetic fields in magnetars.The ultra-strong magnetic field of the magnetars originates really from the induced paramagnetic moment of the 3P2 superfluid with significant mass more than 0.1m⊙ in a condition when their interior temperature here is the energy gap of the neutron 3P2 Cooper pairs. In the case, a phase transition from paramagnetism to ferromagnetism due to the induced paramagnetic moment of 3P2 Cooper pairs in the presence of background magnetic field. The upper limit of the magnetic field for the magnetars is .2 We find that the electron Fermi energy, , increases with the magnetic field strength and it is proportional to . We note that this result is exactly the opposite of the popular idea that the electron Fermi energy decreases with the magnetic field. The key reason for the dilemma is that an incorrect formulae of the microscopic number of states for the electrons in intense magnetic field from some internationally well known popular textbooks on statistical physics has been repeatedly quoted by many authors.3. We propose a new mechanism for the production of the high soft X-ray luminosities of magnetars. In particular, the Fermi energy of the electrons is higher than 60MeV in ultra-strong magnetic fields, B>> Bcr (=4.414´1013 gauss), which is much higher than the Fermi energy of the neutrons. In this case, the process of electron capture (EC) by protons around the proton Femi surface would dominate in magnetars. The outgoing high-energy neutrons due to EC process can easily destroy the Cooper pairs through the nuclear strong interaction. When one Cooper pair is destroyed, the orderly magnetic energy would be released and transformed into disorder thermal energy, then it may be radiated as soft X-rays. The Energy is in the X-ray - soft g-ray range. The total magnetic energy of Cooper pairs can be estimated as . This energy can maintain over yrs for of per magnetar. We have also calculated

  14. How unequal fluxes of high energy astrophysical neutrinos and antineutrinos can fake new physics

    SciTech Connect

    Nunokawa, Hiroshi; Panes, Boris; Funchal, Renata Zukanovich

    2016-10-21

    Flavor ratios of very high energy astrophysical neutrinos, which can be studied at the Earth by a neutrino telescope such as IceCube, can serve to diagnose their production mechanism at the astrophysical source. The flavor ratios for neutrinos and antineutrinos can be quite different as we do not know how they are produced in the astrophysical environment. Due to this uncertainty the neutrino and antineutrino flavor ratios at the Earth also could be quite different. Nonetheless, it is generally assumed that flavor ratios for neutrinos and antineutrinos are the same at the Earth, in fitting the high energy astrophysical neutrino data. This is a reasonable assumption for the limited statistics for the data we currently have. However, in the future the fit must be performed allowing for a possible discrepancy in these two fractions in order to be able to disentangle different production mechanisms at the source from new physics in the neutrino sector. To reinforce this issue, in this work we show that a wrong assumption about the distribution of neutrino flavor ratios at the Earth may indeed lead to misleading interpretations of IceCube results.

  15. Studies of high energy density physics and laboratory astrophysics driven by intense lasers

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2016-10-01

    Laser plasmas are capable of creating unique physical conditions with extreme high energy density, which are not only closely relevant to inertial fusion energy studies, but also to laboratory simulation of some astrophysical processes. In this paper, we highlight some recent progress made by our research teams. The first part is about directional hot electron beam generation and transport for fast ignition of inertial confinement fusion, as well as a new scheme of fast ignition by use of a strong external DC magnetic field. The second part concerns laboratory modeling of some astrophysical phenomena, including 1) studies of the topological structure of magnetic reconnection/annihilation that relates closely to geomagnetic substorms, loop-top X-ray source and mass ejection in solar flares, and 2) magnetic field generation and evolution in collisionless shock formation.

  16. The physics of the earth's core: An introduction

    SciTech Connect

    Melchior, P.

    1986-01-01

    This book is a reference text providing information on physical topics of recent developments in internal geophysics. The text summarizes papers covering theoretical geophysics. Basic formulae, definitions and theorems are not explained in detail due to the limited space. The contents include applications to geodesy, geophysics, astronomy, astrophysics, geophysics and planetary physics. The formal contents include: The Earth's model; Thermodynamics; Hydrodynamics; Geomagnetism; Geophysical implications in the Earth's core.

  17. Analysis of Radon Decay Data and its Implications for Physics, Geophysics, and Solar Physics.

    NASA Astrophysics Data System (ADS)

    Sturrock, Peter A.; Fischbach, E.; Jenkins, J. H.; Steinitz, G.

    2012-05-01

    We present an analysis of about 29,000 measurements of gamma radiation associated with the decay of radon in a sealed container at the Geological Survey of Israel (GSI) Laboratory in Jerusalem between January 28 2007 and May 10 2010. These measurements exhibit strong variations in time of year and time of day, which may be due in part to environmental influences. However, time-series analysis also reveals a number of periodicities, notably at 11.2 year-1 and 12.5 year-1, which we have found in other nuclear-decay data --including data acquired at the Brookhaven National Laboratory and the Physiklisch-Technische Bundesanstalt-- which we attribute to a solar influence. A distinct property of the GSI results is that the annual oscillation is much stronger in daytime data than in nighttime data, but the opposite is true for all other oscillations. We speculate on possible interpretations of this curious result. Solar neutrinos remain our prime suspect as the agent responsible for beta-decay anomalies. These results have implications for physics (that nuclear decay rates are not constant and may be stimulated); for geophysics (that the variability of radon measurements cannot be ascribed entirely to atmospheric and solid-earth processes); and for solar physics (that the Sun contains an inner tachocline, separating a slowly rotating core from the radiative zone, which has properties similar to those of the outer tachocline separating the radiative zone from the convection zone). This work was supported by DOE grant DE-AC-02-76ER071428.

  18. High Energy Astrophysics and Cosmology from Space: NASA's Physics of the Cosmos Program

    NASA Astrophysics Data System (ADS)

    Bautz, Marshall

    2017-01-01

    We summarize currently-funded NASA activities in high energy astrophysics and cosmology embodied in the NASA Physics of the Cosmos program, including updates on technology development and mission studies. The portfolio includes participation in a space mission to measure gravitational waves from a variety of astrophysical sources, including binary black holes, throughout most of cosmic history, and in another to map the evolution of black hole accretion by means of the accompanying X-ray emission. These missions are envisioned as collaborations with the European Space Agency's Large 3 (L3) and Athena programs, respectively. It also features definition of a large, NASA-led X-ray Observatory capable of tracing the surprisingly rapid growth of supermassive black holes during the first billion years of cosmic history. The program also includes the study of cosmic rays and high-energy gamma-ray photons resulting from range of physical processes, and efforts to characterize both the physics of inflation associated with the birth of the universe and the nature of the dark energy that dominates its mass-energy content today. Finally, we describe the activities of the Physics of the Cosmos Program Analysis Group, which serves as a forum for community analysis and input to NASA.

  19. The Physics of Heavy Oils: Implications for Recovery and Geophysical Monitoring

    NASA Astrophysics Data System (ADS)

    Schmitt, Douglas

    2007-03-01

    Our capacity to find and produce conventional light petroleum oils are unable to keep pace with the growth in the growing global demand for energy. With the breakpoint between petroleum production and consumption imminent, a good deal of recent efforts have focused on developing the `heavy' hydrocarbon reserves. Such resources include the extensive heavy oil deposits of Venezuela, the bitumen resources of Canada, and even the solid kerogens (oil shale) of the United States. Capital investments, in particular, have been large in Canada's oil sands due in part to the extensive nature of the resource and already in excess of 30% of Canada's production comes from heavier hydrocarbon deposits. The larger input costs associated with such projects, however, requires that the production be monitored more fully; and this necessitates that both the oils and the porous media which hold them be understood. Geophysical `time-lapse' monitoring seeks to better constrain the areal distribution and movements of fluids in the subsurface by examining the changes in a geophysical response such as seismic reflectivity, micro-gravity variations, or electrical conductivity that arise during production. For example, a changed geophysical seismic character directly depends on relies on variations in the longitudinal and transverse wave speeds and attenuation and mass densities of the materials in the earth. These are controlled by a number of extrinsic conditions such as temperature, fluid pressure, confining stress, and fluid phase and saturation state. Understanding the geophysical signature over a given reservoir requires that the behavior of the porous rock physical properties be well understood and a variety of measurements are being made in laboratories. In current practice, the interpretation of the geophysical field responses is assisted by combined modeling of fluid flow and seismic wave fields. The least understood link in this process, however, is the lack of knowledge on rock

  20. Physics and astrophysics from a lunar base; Proceedings of the 1st NASA Workshop, Stanford, CA, May 19, 20, 1989

    SciTech Connect

    Potter, A.E.; Wilson, T.L.

    1990-01-01

    The present conference on physics and astrophysics from a lunar base encompasses space physics, cosmic ray physics, neutrino physics, experiments in gravitation and general relativity, gravitational radiation physics, cosmic background radiation, particle astrophysics, surface physics, and the physics of gamma rays and X-rays. Specific issues addressed include space-plasma physics research at a lunar base, prospects for neutral particle imaging, the atmosphere as particle detector, medium- and high-energy neutrino physics from a lunar base, muons on the moon, a search for relic supernovae antineutrinos, and the use of clocks in satellites orbiting the moon to test general relativity. Also addressed are large X-ray-detector arrays for physics experiments on the moon, and the measurement of proton decay, arcsec-source locations, halo dark matter and elemental abundances above 10 exp 15 eV at a lunar base.

  1. Astrophysics today

    SciTech Connect

    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.

  2. 22nd SLAC Summer Institute on Particle Physics: Particle physics, astrophysics and cosmology

    NASA Astrophysics Data System (ADS)

    Chan, J.; Deporcel, L.

    The seven-day school portion of the Institute revolved around the question of dark matter: where is it and what is it? Reviews were given of microlensing searches for baryonic dark matter, of dark matter candidates in the form of neutrinos and exotic particles, and of low-noise detection techniques used to search for the latter. The history of the universe, from the Big Bang to the role of dark matter in the formation of large-scale structure, was also covered. Other lecture series described the astrophysics that might be done with x-ray timing experiments and through the detection of gravitational radiation. As in past years, the lectures each morning were followed by stimulating afternoon discussion sessions, in which students could pursue with the lecturers the topics that most interested them. The Institute concluded with a three-day topical conference covering recent developments in theory and experiment. Highlights from the astrophysical and cosmological arenas included observations of anisotropy in the cosmic microwave background, and of the mysterious gamma-ray bursters. From terrestrial accelerators came tantalizing hints of the top quark and marked improvements in precision electroweak measurements, among many other results. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  3. Support for 26th International Conference on Neutrino Physics and Astrophysics

    SciTech Connect

    Kearns, Edward; Feldman, Gary

    2014-06-08

    The XXVI International Conference on Neutrino Physics and Astrophysics (Neutrino 2014) was held in Boston, U.S.A. from June 2 to 7, 2014. The Conference was co-­hosted by Boston University, Harvard University, M.I.T., and Tufts University. The Conference welcomed 549 registered participants from 33 countries. The Boston University Student Village offered an inexpensive housing option and was taken advantage of by 282 attendees. The lecture venue was the George Sherman Union at Boston University. There were 63 scientific presentations by speakers from 15 countries. The Conference held two poster sessions with a total of 287 posters. The Conference featured a reception at the M.I.T. Museum plus a multi-­week exhibition on neutrino physics capped by public presentations on the closing date of the conference. The banquet was a strolling buffet dinner held at the New England Aquarium.

  4. Spectral Modeling in Astrophysics - The Physics of Non-equilibrium Clouds

    NASA Astrophysics Data System (ADS)

    Ferland, Gary; Williams, Robin

    2016-02-01

    Collisional-radiative spectral modeling plays a central role in astrophysics, probing phenomena ranging from the chemical evolution of the Universe to the energy production near supermassive black holes in distant quasars. The observed emission lines form in non-equilibrium clouds that have very low densities by laboratory standards, and are powered by energy sources which themselves are not in equilibrium. The spectrum is the result of a large number of microphysical processes, thermal statistics often do not apply, and analytical theory cannot be used. Numerical simulations are used to understand the physical state and the resulting spectrum. The greatest distinction between astrophysical modeling and conventional plasma simulations lies in the range of phenomena that must be considered. A single astronomical object will often have gas with kinetic temperatures of T˜10^6 K, 10^4 K, and T≤ 10^3 K, with the physical state ranging from molecular to fully ionized, and emitting over all wavelengths between the radio and x-ray. Besides atomic, plasma, and chemical physics, condensed matter physics is important because of the presence of small solid `grains' which affect the gas through catalytic reactions and the infrared emission they produce. The ionization, level populations, chemistry, and grain properties must be determined self-consistently, along with the radiation transport, to predict the observed spectrum. Although the challenge is great, so are the rewards. Numerical spectral simulations allow us to read the message contained in the spectrum emitted by objects far from the Earth that existed long ago.

  5. Geophysical methods

    SciTech Connect

    Robert, E.S.

    1989-01-01

    Geophysical measurements involve no magic or mystery but straightforward applications of physical principles. This book is both a geophysical survey and a reference guide. It explains the physical principles involved in geophysical methods. Over one-third of the text is devoted to seismic methods. Comprehensive topics in the volume include: the measurement of different physical properties and their geological significance; how different kinds of measurements are combined to draw geological conclusions; surface, borehole, airborne, and satellite measurements; computer processing and interactive methods; geodetic, gravity, magnetic, radioactive, heat flow, and electrical methods; interpretation of natural processes such as earthquakes and heat flow; and a summation of present knowledge of the earth.

  6. Physics with gamma-beams and charged particle detectors: I) Nuclear structure II) Nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Gai, Moshe

    2015-02-01

    The Charged Particle Working Group (CPWG) is proposing to construct large area Silicon Strip Detector (SSD), a gas Time Projection Chamber detector read by an electronic readout system (eTPC) and a Bubble Chamber (BC) containing superheated high purity water to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We intend to use the SSD and eTPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as 12C and 16O . All three detectors (SSD, eTPC and BC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the 12C (α,γ) reaction and other processes central to stellar evolution. The CPWG intends to submit to the ELI-NP facility a Technical Design Report (TDR) for the proposed detectors.

  7. Physics with gamma-beams and charged particle detectors: I) Nuclear structure II) Nuclear astrophysics

    SciTech Connect

    Gai, Moshe

    2015-02-24

    The Charged Particle Working Group (CPWG) is proposing to construct large area Silicon Strip Detector (SSD), a gas Time Projection Chamber detector read by an electronic readout system (eTPC) and a Bubble Chamber (BC) containing superheated high purity water to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We intend to use the SSD and eTPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as {sup 12}C and {sup 16}O. All three detectors (SSD, eTPC and BC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the {sup 12}C(α,γ) reaction and other processes central to stellar evolution. The CPWG intends to submit to the ELI-NP facility a Technical Design Report (TDR) for the proposed detectors.

  8. Lecture Notes and Essays in Astrophysics.III. 3rd Symposium of the Astrophysics Group of the Spanish Royal Physical Society (RSEF).

    NASA Astrophysics Data System (ADS)

    Ulla, A.; Manteiga, M.

    2008-12-01

    The Third volume of "Lecture Notes and Essays in Astrophysics" highlights some important contributions of Spanish astrophysicists to Planetology, Solar and Stellar Physics, Extragalactic Astronomy, Cosmology and astronomical instrumentation. After decades without a dedicated mission, Venus is again in fashion. On the one hand, Ricardo Hueso and collaborators, and on the other Miguel Angel Lopez-Valverde, review ESA Venus Express contribution to the understanding of the atmosphere of the neighbouring planet. Carme Jordi describes in a comprehensive essay the main observational calibration techniques and methods for the determination of mass, radius, temperature, chemical composition and luminosity of a star. Dying stars are fundamental to understand the nature of dark energy, probably the most fundamental problem in Physics today. Type Ia supernovae have played a fundamental role showing the acceleration of the expansion rate of the Universe a decade ago. Inma Dominguez and collaborators go into detail on how the knowledge of the fundamental physics of thermonuclear supernovae explotions condition their role as astrophysical candles.

  9. Impact on Astrophysics and Elementary Particle Physics of recent and future Solar Neutrino data

    NASA Astrophysics Data System (ADS)

    Antonelli, V.; Miramonti, L.

    2014-06-01

    The study of neutrinos is fundamental to connect astrophysics and elementary particle physics. In this last decade solar neutrino experiments and Kam-LAND confirmed the LMA solution and further clarified the oscillation pattern. Borexino attacked also the study of the low energy neutrino spectrum. However, important points still need clarification, like the apparent anomaly in the vacuum to matter transition region. Besides, a more detailed study of the low energy components of the pp cycle, combined with a measurement of CNO fluxes, is compulsory, also to discriminate between the low and the high Z versions of the Solar Standard Models and solve the metallicity problem. We discuss the main recent advancements and the possibilities of studying these open problems with Borexino, SNO+ and the future experiments, like the next generation of scintillators.

  10. Hans A. Bethe Prize: Astrophysical, observational and nuclear-physics aspects of r-process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Kratz, Karl-Ludwig

    2014-03-01

    Guided by the Solar System (S.S.) abundance peaks at A ~= 130 and A ~= 195, the basic mechanisms for the rapid neutron-capture process (the r-process) have been known for over 50 years. However, even today, all proposed scenarios and sites face problems with astrophysical conditions as well as with the necessary nuclear-physics input. In my talk, I will describe efforts in experimental and theoretical nuclear-structure data for modeling today's three groups of r-process ``observables'', i.e. the bulk S.S. isotopic abundances, the elemental abundances in metal-poor halo stars, and peculiar isotopic patterns measured in certain cosmic stardust grains. To set a historical basis, I will briefly recall our site-independent ``waiting-point'' model, with superpositions of neutron-density components and the use of the first global, unified nuclear input based on the mass model FRDM(1992). This approach provided a considerable leap forward in the basic understanding of the required astrophysical conditions, as well as of specific shell-structure properties far from stability. Starting in the early millenium, the above simple model has been replaced by more realistic, dynamical parameter studies within the high-entropy wind scenario of core-collapse supernovae, now with superpositions of entropy (S) and electron-fraction (Ye) components. Furthermore, an improved, global set of nuclear-physics data is used today, based on the new mass model FRDM(2012). With this nuclear and astrophysics parameter combination, a new fit to the S.S. r-abundances will be shown, and its improvements and remaining deficiencies in terms of underlying shell structure will be discussed. Concerning the abundance patterns in metal-poor halo stars, an interpretation of the production of ``r-rich'' (e.g. CS 22892-052) and ``r-poor'' (e.g. HD 122563) stars in terms of different (Ye), S combinations will be presented. Finally, for the third group of ``r-observables'', a possible origin of the anomalous Xe

  11. 5th International conference on Physics and Astrophysics of Quark Gluon Plasma

    NASA Astrophysics Data System (ADS)

    Sinha, Bikash; Alam, Jan-E.; Nayak, Tapan K.

    2006-11-01

    The 5th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP 2005) was held on 8 - 12 February 2005 at the Variable Energy Cyclotron Centre and Saha Institute of Nuclear Physics campus, Kolkata, India. The conference was enriched by the august presence of about 300 participants representing 18 countries across the globe. It had plenary talks and oral presentations, which form a part of these proceedings. Besides invited and contributed talks there were also a large number of poster presentations. The conference was energized by discussions of fresh experimental data from RHIC on strong elliptic flow, jet quenching, single photon spectra etc. Moreover, new theoretical results were brought to the discussion forum during this conference. Colour glass condensates, hydrodynamical flow, jet quenching and sQGP were intensely debated by the participants. The highlight of ICPAQGP 2005 was the presentation of fresh experimental results from the RHIC-IV run. The ICPAQGP series, since its inception in 1988, has placed emphasis on the role of quark matter in the fields of astrophysics and cosmology. The subsequent conferences held in 1993, 1997, 2001 and 2005 had also retained this focus. The conference was preceded by a Fest Colloquium in honour of Professor Bikash Sinha. Professor Sinha, regarded as the pioneer in establishing quark gluon plasma research in India, has successfully encouraged a group of young Indian researchers to devote themselves wholeheartedly to QGP research - both theoretical and experimental. Members of the International Advisory Committee played a pivotal role mainly in the selection of speakers. The contributions of the Organizing Committee in all aspects, from selecting the contributory talks posters down to arranging local hospitality, were much appreciated. We thank the members of both committees for making ICPAQGP 2005 an interesting platform for scientific deliberation. The ICPAQGP 2005 was supported financially by

  12. White paper on nuclear astrophysics and low-energy nuclear physics, Part 2: Low-energy nuclear physics

    DOE PAGES

    Carlson, Joe; Carpenter, Michael P.; Casten, Richard; ...

    2017-05-01

    In preparation for the 2015 NSAC Long Range Plan (LRP), the DNP town meetings on Nuclear Astrophysics and Low-Energy Nuclear Physics were held at the Mitchell Center on the campus of Texas A&M University August 21–23, 2014. Participants met in a number of topic-oriented working groups to discuss progress since the 2007 LRP, compelling science opportunities, and the resources needed to advance them. These considerations were used to determine priorities for the next five to ten years. In addition, approximately 270 participants attended the meetings, coming from US national laboratories, a wide range of US universities and other research institutionsmore » and universities abroad.« less

  13. Electron-positron pairs in physics and astrophysics: From heavy nuclei to black holes

    NASA Astrophysics Data System (ADS)

    Ruffini, Remo; Vereshchagin, Gregory; Xue, She-Sheng

    2010-02-01

    Due to the interaction of physics and astrophysics we are witnessing in these years a splendid synthesis of theoretical, experimental and observational results originating from three fundamental physical processes. They were originally proposed by Dirac, by Breit and Wheeler and by Sauter, Heisenberg, Euler and Schwinger. For almost seventy years they have all three been followed by a continued effort of experimental verification on Earth-based experiments. The Dirac process, e+e-→2γ, has been by far the most successful. It has obtained extremely accurate experimental verification and has led as well to an enormous number of new physics in possibly one of the most fruitful experimental avenues by introduction of storage rings in Frascati and followed by the largest accelerators worldwide: DESY, SLAC etc. The Breit-Wheeler process, 2γ→e+e-, although conceptually simple, being the inverse process of the Dirac one, has been by far one of the most difficult to be verified experimentally. Only recently, through the technology based on free electron X-ray laser and its numerous applications in Earth-based experiments, some first indications of its possible verification have been reached. The vacuum polarization process in strong electromagnetic field, pioneered by Sauter, Heisenberg, Euler and Schwinger, introduced the concept of critical electric field Ec=me2c3/(eħ). It has been searched without success for more than forty years by heavy-ion collisions in many of the leading particle accelerators worldwide. The novel situation today is that these same processes can be studied on a much more grandiose scale during the gravitational collapse leading to the formation of a black hole being observed in Gamma Ray Bursts (GRBs). This report is dedicated to the scientific race. The theoretical and experimental work developed in Earth-based laboratories is confronted with the theoretical interpretation of space-based observations of phenomena originating on cosmological

  14. Nuclear physics and astrophysics. Progress report, July 15, 1991--June 15, 1992

    SciTech Connect

    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.

  15. Astrophysical Cause of Tectonics

    NASA Astrophysics Data System (ADS)

    Mensur, O.

    2016-05-01

    Tectonic earthquakes, of Mw (6 ± 5%)+, are found forming a strengthening-peaking-waning pattern distinguishable from respectively quiescent times so well that the pattern means discovery of a universal natural mechanism that necessitates expanding on classical physics. The pattern is seen only during Earth's alignments to two other heavenly bodies in our solar system lasting for more than 3 days. This empirical proof of astrophysical origins of seismotectonics is immediately obvious and verifiable. The find is consequential due to sheer size of processes and energies involved in defining the pattern that now enables all-or-nothing negative forecasting by foretelling dates without strong quakes. Near co-planarity of a solar system's planets, which is for our solar system typically regarded an oddity, is in fact a necessary condition for active geophysics as a life system.

  16. High Energy Astrophysics and Cosmology from Space: NASA's Physics of the Cosmos Program

    NASA Astrophysics Data System (ADS)

    Hornschemeier, Ann

    2016-03-01

    We summarize currently-funded NASA activities in high energy astrophysics and cosmology, embodied in the NASA Physics of the Cosmos program, including updates on technology development and mission studies. The portfolio includes development of a space mission for measuring gravitational waves from merging supermassive black holes, currently envisioned as a collaboration with the European Space Agency (ESA) on its L3 mission and development of an X-ray observatory that will measure X-ray emission from the final stages of accretion onto black holes, currently envisioned as a NASA collaboration on ESA's Athena observatory. The portfolio also includes the study of cosmic rays and gamma ray photons resulting from a range of processes, of the physical process of inflation associated with the birth of the universe and of the nature of the dark energy that dominates the mass-energy of the modern universe. The program is supported by an analysis group called the PhysPAG that serves as a forum for community input and analysis and the talk will include a description of activities of this group.

  17. From astrophysics to mesoscopic physics: a sightseeing tour in the world of clusters and fullerenes

    NASA Astrophysics Data System (ADS)

    Rosen, Arne; Ostling, Daniel; Apell, P.; Tomanek, D.

    1996-12-01

    The discovery of the fullerenes in 1985 by Kroto, Heath, O'Brien, Curl and Smalley and the development of a method for production of macroscopic amounts in 1990 by Kraetschmer, Lamb, Fostiropoulos and Huffman opened a new area of carbon research with possible production of new materials with unique properties. The field has developed further later on with discoveries of nanotubes, metal filled nanotubes, carbon onions and more recently metal covered fullerenes. All these new discoveries show how cluster science opens approaches to the area of meososcopic physics. The general trend is here in the direction from small to large contrary to the general trend of modern meososcopic physics or micro-electronics where the movement is from large to small. It is especially fascinating how the whole area of fullerene research was initiated by problems in astrophysics. Originally Kraetschmer and Huffman had the intention to explain an observed strong extinction form interstellar dust and produced in experiments special carbon soot with a characteristics optical absorption known as 'the camel hump smoke'. This paper gives a short overview of some of our more recent theoretical work of the electronic properties of C60, metal covered C60 and nanotubes. In addition some results are also presented of optical properties of metal covered C60 as a function of metal coverage.

  18. The Dresden Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics - Status and first physics program

    SciTech Connect

    Ilgner, Ch.

    2015-07-01

    Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, protected from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise using the same High-Purity Ge detector at several sites has shown that, with a combination of 45 m rock overburden, as can be found in the Felsenkeller underground site in Dresden, and an active veto against the remaining muon flux, in a typical nuclear astrophysics setup a background level can be achieved that is similar to the deep underground scenario as in the Gran- Sasso underground laboratory, for instance. Recently, a muon background study and geodetic measurements were carried out by the REGARD group. It was estimated that the rock overburden at the place of the future ion accelerator is equivalent to 130 m of water. The maximum muon flux measured was 2.5 m{sup -2} sr{sup -1} s{sup -1}, in the direction of the tunnel entrance. Based on this finding, a used 5 MV pelletron tandem accelerator with 250 μA up-charge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is in progress and far advanced. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the

  19. Nuclear physics and astrophysics. Progress report for period June 15, 1992--June 14, 1993

    SciTech Connect

    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.

  20. Nuclear Incompressibility and the Asymmetry Term: Implications for Astrophysics and Physics with Exotic Nuclei

    SciTech Connect

    Fujiwara, M.

    2010-06-01

    The compressional-mode giant resonances, the isoscalar giant monopole resonance (GMR) and the isoscalar giant dipole resonance (ISGDR), in various isotopes have been investigated using inelastic scattering of 400-MeV alpha-particles at extremely forward angles, including 0 deg. Recently, the centroid energies of the giant monopole resonance (GMR) in the Sn isotope region are found to be significantly lower than the theoretical predictions. In addition, based on the GMR results, the asymmetry-term in the nuclear incompressibility has been determined as K{sub t}au = -550+-100 MeV. Constraints on interactions employed in nuclear structure calculations are discussed on the basis of the experimentally values for K{sub i}nfinity and K{sub t}au. The combination of these two values gives stringent constraints on the interactions used for nuclear structure calculations and for formations of equation of state (EOS) of nuclear matter. A short review of the current status of the experimental studies on the compressional-mode giant resonances is given, and a possible new experiment for astrophysics and physics with exotic nuclei is suggested.

  1. J-PAS: The Javalambre Physics of the Accelerated Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Cepa, J.; Benítez, N.; Dupke, R.; Moles, M.; Sodré, L.; Cenarro, A. J.; Marín-Franch, A.; Taylor, K.; Cristóbal, D.; Fernández-Soto, A.; Mendes de Oliveira, C.; Abramo, L. R.; Alcaniz, J. S.; Overzier, R.; Hernández-Monteagudo, A.; Alfaro, E. J.; Kanaan, A.; Carvano, M.; Reis, R. R. R.; J-PAS Team

    2016-10-01

    The Javalambre Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5 m telescope and a 4.7 sq.deg. camera with 1.2 Gpix. Starting in late 2016, J-PAS will observe 8500 sq.deg. of Northern Sky and measure Δz˜0.003(1+z) photo-z for 9× 107 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ˜ 14 Gpc3 up to z=1.3 and becoming the first radial BAO experiment to reach Stage IV. J-PAS will detect 7× 105 galaxy clusters and groups, setting constraints on Dark Energy which rival those obtained from its BAO measurements. Thanks to the superb characteristics of the site (seeing ˜ 0.7 arcsec), J-PAS is expected to obtain a deep, sub-arcsec image of the Northern sky, which combined with its unique photo-z precision will produce one of the most powerful cosmological lensing surveys before the arrival of Euclid. J-PAS's unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure σz˜ 0.5 redshifts for ˜ 4000 SNeIa and ˜ 900 core-collapse SNe. The key to the J-PAS potential is its innovative approach: a contiguous system of 54 filters with 145 Å width, placed 100 Å apart over a multi-degree FoV is a powerful redshift machine, with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. The J-PAS camera is equivalent to a 4.7 sq.deg. IFU and it will produce a time-resolved, 3D image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby Universe and the study of resolved stellar populations.

  2. Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Jones, Bernard J. T.; Markovic, Dragoljub

    1997-06-01

    Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.

  3. Astrophysical symmetries

    PubMed Central

    Trimble, Virginia

    1996-01-01

    Astrophysical objects, ranging from meteorites to the entire universe, can be classified into about a dozen characteristic morphologies, at least as seen by a blurry eye. Some patterns exist over an enormously wide range of distance scales, apparently as a result of similar underlying physics. Bipolar ejection from protostars, binary systems, and active galaxies is perhaps the clearest example. The oral presentation included about 130 astronomical images which cannot be reproduced here. PMID:11607715

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Data catalog series for space science and applications flight missions. Volume 5A: Descriptions of astronomy, astrophysics, and solar physics spacecraft and investigations. Volume 5B: Descriptions of data sets from astronomy, astrophysics, and solar physics spacecraft and investigations

    NASA Technical Reports Server (NTRS)

    Kim, Sang J. (Editor)

    1988-01-01

    The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets of astronomy, astrophysics, solar physics spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided.

  6. Particle Geophysics

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyuki K. M.

    2014-05-01

    Geophysics research has long been dominated by classical mechanics, largely disregarding the potential of particle physics to augment existing techniques. The purpose of this article is to review recent progress in probing Earth's interior with muons and neutrinos. Existing results for various volcanological targets are reviewed. Geoneutrinos are also highlighted as examples in which the neutrino probes elucidate the composition of Earth's deep interior. Particle geophysics has the potential to serve as a useful paradigm to transform our understanding of Earth as dramatically as the X-ray transformed our understanding of medicine and the body.

  7. Astrophysics and astronomy (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 26 January 2011)

    NASA Astrophysics Data System (ADS)

    2011-10-01

    An Astrophysics and Astronomy scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held in the Conference Hall of the P N Lebedev Physical Institute, RAS, on 26 January 2011. The following reports were put on the session's agenda posted on the web site www.gpad.ac.ru of the Physical Sciences Division, RAS: (1) Cherepashchuk A M (Sternberg Astronomical Institute, Moscow State University, Moscow) "Investigation of X-ray sources"; (2) Shustov B M (Institute of Astronomy, Russian Academy of Sciences, Moscow) "Asteroid and comet hazards: physical and other aspects"; (3) Sazhin M V (Sternberg Astronomical Institute, Moscow State University, Moscow) "Search for cosmic strings"; (4) Zakharov A F (Russian Federation State Scientific Center 'A I Alikhanov Institute for Theoretical and Experimental Physics', Moscow) "Exoplanet search using gravitational microlensing". Papers written on the basis of the reports are published below. • Optical investigations of X-ray binary systems, A M Cherepashchuk Physics-Uspekhi, 2011, Volume 54, Number 10, Pages 1061-1067 • Asteroid and comet hazards: the role of physical sciences in solving the problem, B M Shustov Physics-Uspekhi, 2011, Volume 54, Number 10, Pages 1068-1071 • Search for cosmic strings using optical and radio astronomy methods, O S Sazhina, M V Sazhin, M Capaccioli, G Longo Physics-Uspekhi, 2011, Volume 54, Number 10, Pages 1072-1077 • Search for exoplanets using gravitational microlensing, A F Zakharov Physics-Uspekhi, 2011, Volume 54, Number 10, Pages 1077-1084

  8. Institute of Geophysics and Planetary Physics (IGPP), Lawrence Livermore National Laboratory (LLNL): Quinquennial report, November 14-15, 1996

    SciTech Connect

    Tweed, J.

    1996-10-01

    This Quinquennial Review Report of the Lawrence Livermore National Laboratory (LLNL) branch of the Institute for Geophysics and Planetary Physics (IGPP) provides an overview of IGPP-LLNL, its mission, and research highlights of current scientific activities. This report also presents an overview of the University Collaborative Research Program (UCRP), a summary of the UCRP Fiscal Year 1997 proposal process and the project selection list, a funding summary for 1993-1996, seminars presented, and scientific publications. 2 figs., 3 tabs.

  9. Particle astrophysics

    NASA Technical Reports Server (NTRS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    1991-01-01

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  10. Particle astrophysics

    NASA Astrophysics Data System (ADS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  11. Theory and laboratory astrophysics

    NASA Technical Reports Server (NTRS)

    Schramm, David N.; Mckee, Christopher F.; Alcock, Charles; Allamandola, Lou; Chevalier, Roger A.; Cline, David B.; Dalgarno, Alexander; Elmegreen, Bruce G.; Fall, S. Michael; Ferland, Gary J.

    1991-01-01

    Science opportunities in the 1990's are discussed. Topics covered include the large scale structure of the universe, galaxies, stars, star formation and the interstellar medium, high energy astrophysics, and the solar system. Laboratory astrophysics in the 1990's is briefly surveyed, covering such topics as molecular, atomic, optical, nuclear and optical physics. Funding recommendations are given for the National Science Foundation, NASA, and the Department of Energy. Recommendations for laboratory astrophysics research are given.

  12. Narratives of the double bind: Intersectionality in life stories of women of color in physics, astrophysics and astronomy

    NASA Astrophysics Data System (ADS)

    Ko, Lily T.; Kachchaf, Rachel R.; Ong, Maria; Hodari, Apriel K.

    2013-01-01

    This paper presents themes on the life stories of women of color in physics, astrophysics and astronomy. Drawing from our NSF-sponsored project, Beyond the Double Bind: Women of Color in STEM, we share findings from 10 interviews and 41 extant texts (about 23 women in varied life stages). Employing intersectionality theory and narrative analysis, our study contributes a critical analysis of how the intersection of gender and race affects performance, identity, persistence and overall career and education experiences in the physical sciences. Our findings both support existing literature on women of color in STEM, as well as bring to light two major, emergent issues: the importance of activism, and school/work-life balance. This research will add to the knowledge base about strategies for retaining women of color--widely considered an untapped source of domestic talent that could fill the country's scientific workforce needs.

  13. Preliminary Physical Stratigraphy and Geophysical Data From the USGS Dixon Core, Onslow County, North Carolina

    USGS Publications Warehouse

    Seefelt, Ellen L.; Gonzalez, Wilma Aleman B.; Self-Trail, Jean M.; Weems, Robert E.; Edwards, Lucy E.; Pierce, Herbert A.; Durand, Colleen T.

    2009-01-01

    In October through November 2006, scientists from the U. S. Geological Survey (USGS) Eastern Region Earth Surface Processes Team (EESPT) and the Raleigh (N.C.) Water Science Center (WSC), in cooperation with the North Carolina Geological Survey (NCGS) and the Onslow County Water and Sewer Authority (ONWASA), drilled a stratigraphic test hole and well in Onslow County, N.C. The Dixon corehole was cored on ONWASA water utility property north of the town of Dixon, N.C., in the Sneads Ferry 7.5-minute quadrangle at latitude 34deg33'35' N, longitude 77deg26'54' W (decimal degrees 34.559722 and -77.448333). The site elevation is 66.0 feet (ft) above mean sea level as determined using a Paulin precision altimeter. The corehole attained a total depth of 1,010 ft and was continuously cored by the USGS EESPT drilling crew. A groundwater monitoring well was installed in the screened interval between 234 and 254 ft below land surface. The section cored at this site includes Upper Cretaceous, Paleogene, and Neogene sediments. The Dixon core is stored at the NCGS Coastal Plain core storage facility in Raleigh. The Dixon corehole is the fourth and last in a series of planned North Carolina benchmark coreholes drilled by the USGS Coastal Carolina Project. These coreholes explore the physical stratigraphy, facies, and thickness of Cretaceous, Paleogene, and Neogene Coastal Plain sediments in North Carolina. Correlations of lithologies, facies, and sequence stratigraphy can be made with the Hope Plantation corehole, N.C., near Windsor in Bertie County (Weems and others, 2007); the Elizabethtown corehole, near Elizabethtown, N.C., in Bladen County (Self-Trail and others, 2004b); the Smith Elementary School corehole, near Cove City, N.C., in Craven County (Harris and Self-Trail, 2006; Crocetti, 2007); the Kure Beach corehole, near Wilmington, N.C., in New Hanover County (Self-Trail and others, 2004a); the Esso#1, Esso #2, Mobil #1, and Mobil #2 cores in Albermarle and Pamlico Sounds

  14. Constraining the astrophysical origin of the p-nuclei through nuclear physics and meteoritic data.

    PubMed

    Rauscher, T; Dauphas, N; Dillmann, I; Fröhlich, C; Fülöp, Zs; Gyürky, Gy

    2013-06-01

    A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-processes. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of pre-existing intermediate and heavy nuclei. This so-called γ-process requires high stellar plasma temperatures and occurs mainly in explosive O/Ne burning during a core-collapse supernova. Although the γ-process in massive stars has been successful in producing a large range of p-nuclei, significant deficiencies remain. An increasing number of processes and sites has been studied in recent years in search of viable alternatives replacing or supplementing the massive star models. A large number of unstable nuclei, however, with only theoretically predicted reaction rates are included in the reaction network and thus the nuclear input may also bear considerable uncertainties. The current status of astrophysical models, nuclear input and observational constraints is reviewed. After an overview of currently discussed models, the focus is on the possibility to better constrain those models through different means. Meteoritic data not only provide the actual isotopic abundances of the p-nuclei but can also put constraints on the possible contribution of proton-rich nucleosynthesis. The main part of the review focuses on the nuclear uncertainties involved in the determination of the astrophysical reaction rates required for the extended reaction networks used in nucleosynthesis studies. Experimental approaches are discussed together with their necessary connection to theory, which is especially pronounced for reactions with intermediate and heavy nuclei in explosive nuclear burning, even close to stability.

  15. Astrophysics and Space Science

    NASA Astrophysics Data System (ADS)

    Mould, Jeremy; Brinks, Elias; Khanna, Ramon

    2015-08-01

    Astrophysics and Space Science publishes original contributions and invited reviews covering the entire range of astronomy, astrophysics, astrophysical cosmology, planetary and space science, and the astrophysical aspects of astrobiology. This includes both observational and theoretical research, the techniques of astronomical instrumentation and data analysis, and astronomical space instrumentation. We particularly welcome papers in the general fields of high-energy astrophysics, astrophysical and astrochemical studies of the interstellar medium including star formation, planetary astrophysics, the formation and evolution of galaxies and the evolution of large scale structure in the Universe. Papers in mathematical physics or in general relativity which do not establish clear astrophysical applications will not longer be considered.The journal also publishes topical collections consisting of invited reviews and original research papers selected special issues in research fields of particular scientific interest. These consist of both invited reviews and original research papers.Conference proceedings will not be considered. All papers published in the journal are subject to thorough and strict peer-reviewing.Astrophysics and Space Science has an Impact Factor of 2.4 and features short editorial turnaround times as well as short publication times after acceptance, and colour printing free of charge. Published by Springer the journal has a very wide online dissemination and can be accessed by researchers at a very large number of institutes worldwide.

  16. A Hitch-hiker's Guide to Stochastic Differential Equations - Solution Methods for Energetic Particle Transport in Space Physics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Strauss, R. Du Toit; Effenberger, Frederic

    2017-03-01

    In this review, an overview of the recent history of stochastic differential equations (SDEs) in application to particle transport problems in space physics and astrophysics is given. The aim is to present a helpful working guide to the literature and at the same time introduce key principles of the SDE approach via "toy models". Using these examples, we hope to provide an easy way for newcomers to the field to use such methods in their own research. Aspects covered are the solar modulation of cosmic rays, diffusive shock acceleration, galactic cosmic ray propagation and solar energetic particle transport. We believe that the SDE method, due to its simplicity and computational efficiency on modern computer architectures, will be of significant relevance in energetic particle studies in the years to come.

  17. Black Hole Physics and Astrophysics: The GRB-Supernova Connection and URCA-1 - URCA-2

    NASA Astrophysics Data System (ADS)

    Ruffini, R.; Bernardini, M. G.; Bianco, C. L.; Vitagliano, L.; Xue, S.-S.; Chardonnet, P.; Fraschetti, F.; Gurzadyan, V.

    2006-02-01

    We outline the confluence of three novel theoretical fields in our modeling of Gamma-Ray Bursts (GRBs): 1) the ultrarelativistic regime of a shock front expanding with a Lorentz gamma factor 300; 2) the quantum vacuum polarization process leading to an electron-positron plasma originating the shock front; and 3) the general relativistic process of energy extraction from a black hole originating the vacuum polarization process. There are two different classes of GRBs: the long GRBs and the short GRBs. We here address the issue of the long GRBs. The theoretical understanding of the long GRBs has led to the detailed description of their luminosities in fixed energy bands, of their spectral features and made also possible to probe the astrophysical scenario in which they originate. We are specially interested, in this report, to a subclass of long GRBs which appear to be accompanied by a supernova explosion. We are considering two specific examples: GRB980425/SN1998bw and GRB030329/SN2003dh. While these supernovae appear to have a standard energetics of 1049 ergs, the GRBs are highly variable and can have energetics 104 - 105 times larger than the ones of the supernovae. Moreover, many long GRBs occurs without the presence of a supernova. It is concluded that in no way a GRB can originate from a supernova. The precise theoretical understanding of the GRB luminosity we present evidence, in both these systems, the existence of an independent component in the X-ray emission, usually interpreted in the current literature as part of the GRB afterglow. This component has been observed by Chandra and XMM to have a strong decay on scale of months. We have named here these two sources respectively URCA-1 and URCA-2, in honor of the work that George Gamow and Mario Shoenberg did in 1939 in this town of Urca identifying the basic mechanism, the Urca processes, leading to the process of gravitational collapse and the formation of a neutron star and a supernova. The further

  18. A Deuterated Neutron Detector Array For Nuclear (Astro)Physics Studies

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, Sergio; Asher, B. W.; Barber, P.; Hanselman, K.; Perello, J. F.

    2016-09-01

    The properties of neutron-rich nuclei are at the forefront of research in nuclear structure, nuclear reactions and nuclear astrophysics. The advent of intense rare isotope beams (RIBs) has opened a new door for studies of systems with very short half-lives and possible fascinating properties. Neutron spectroscopic techniques become increasingly relevant when these neutron rich nuclei are used in a variety of experiments. At Florida State University, we are developing a neutron detector array that will allow us to perform high-resolution neutron spectroscopic studies with stable and radioactive beams. The neutron detection system consists of 16 deuterated organic liquid scintillation detectors with fast response and pulse-shape discrimination capabilities. In addition to these properties, there is the potential to use the structure in the pulse-height spectra to extract the energy of the neutrons and thus produce directly excitation spectra. This type of detector uses deuterated benzene (C6D6) as the liquid scintillation medium. The asymmetric nature of the scattering between a neutron and a deuterium in the center of mass produces a pulse-height spectrum from the deuterated scintillator which contains useful information on the initial energy of the neutron. Work supported in part by the State of Florida and NSF Grant No. 1401574.

  19. Program report for FY 1984 and 1985 Atmospheric and Geophysical Sciences Division of the Physics Department

    SciTech Connect

    Knox, J.B.; MacCracken, M.C.; Dickerson, M.H.; Gresho, P.M.; Luther, F.M.

    1986-08-01

    This annual report for the Atmospheric and Geophysical Sciences Division (G-Division) summarizes the activities and highlights of the past three years, with emphasis on significant research findings in two major program areas: the Atmospheric Release Advisory Capability (ARAC), with its recent involvement in assessing the effects of the Chernobyl reactor accident, and new findings on the environmental consequences of nuclear war. The technical highlights of the many other research projects are also briefly reported, along with the Division's organization, budget, and publications.

  20. Advances in Small Pixel TES-Based X-Ray Microcalorimeter Arrays for Solar Physics and Astrophysics

    NASA Technical Reports Server (NTRS)

    Bandler, S. R.; Adams, J. S.; Bailey, C. N.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Porst, J.-P.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We are developing small-pixel transition-edge-sensor (TES) for solar physics and astrophysics applications. These large format close-packed arrays are fabricated on solid silicon substrates and are designed to accommodate count-rates of up to a few hundred counts/pixel/second at a FWHM energy resolution approximately 2 eV at 6 keV. We have fabricated versions that utilize narrow-line planar and stripline wiring. We present measurements of the performance and uniformity of kilo-pixel arrays, incorporating TESs with single 65-micron absorbers on a 7s-micron pitch, as well as versions with more than one absorber attached to the TES, 4-absorber and 9-absorber "Hydras". We have also fabricated a version of this detector optimized for lower energies and lower count-rate applications. These devices have a lower superconducting transition temperature and are operated just above the 40mK heat sink temperature. This results in a lower heat capacity and low thermal conductance to the heat sink. With individual single pixels of this type we have achieved a FWHM energy resolution of 0.9 eV with 1.5 keV Al K x-rays, to our knowledge the first x-ray microcalorimeter with sub-eV energy resolution. The 4-absorber and 9-absorber versions of this type achieved FWHM energy resolutions of 1.4 eV and 2.1 eV at 1.5 keV respectively. We will discuss the application of these devices for new astrophysics mission concepts.

  1. Computer simulation of astrophysical plasmas

    NASA Technical Reports Server (NTRS)

    Max, Claire E.

    1991-01-01

    The role of sophisticated numerical models and simulations in the field of plasma astrophysics is discussed. The need for an iteration between microphysics and macrophysics in order for astrophysical plasma physics to produce quantitative results that can be related to astronomical data is stressed. A discussion on computational requirements for simulations of astrophysical plasmas contrasts microscopic plasma simulations with macroscopic system models. An overview of particle-in-cell simulations (PICS) is given and two examples of PICS of astrophysical plasma are discussed including particle acceleration by collisionless shocks in relativistic plasmas and magnetic field reconnection in astrophysical plasmas.

  2. SPAN: Astronomy and astrophysics

    NASA Technical Reports Server (NTRS)

    Thomas, Valerie L.; Green, James L.; Warren, Wayne H., Jr.; Lopez-Swafford, Brian

    1987-01-01

    The Space Physics Analysis Network (SPAN) is a multi-mission, correlative data comparison network which links science research and data analysis computers in the U.S., Canada, and Europe. The purpose of this document is to provide Astronomy and Astrophysics scientists, currently reachable on SPAN, with basic information and contacts for access to correlative data bases, star catalogs, and other astrophysic facilities accessible over SPAN.

  3. Baryon isocurvature scenario in inflationary cosmology - A particle physics model and its astrophysical implications

    NASA Technical Reports Server (NTRS)

    Yokoyama, Jun'ichi; Suto, Yasushi

    1991-01-01

    A phenomenological model to produce isocurvature baryon-number fluctuations is proposed in the framework of inflationary cosmology. The resulting spectrum of density fluctuation is very different from the conventional Harrison-Zel'dovich shape. The model, with the parameters satisfying several requirements from particle physics and cosmology, provides an appropriate initial condition for the minimal baryon isocurvature scenario of galaxy formation discussed by Peebles.

  4. News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

    NASA Astrophysics Data System (ADS)

    2011-01-01

    Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

  5. Role of magnetic fields in physics and astrophysics; Proceedings of the Conference, Copenhagen, Denmark, June 5-7, 1974

    NASA Technical Reports Server (NTRS)

    Canuto, V.

    1975-01-01

    The papers deal with the role of magnetism in astrophysics and the properties of matter in the presence of unusually large magnetic fields. Topics include a quantum-mechanical treatment of high-energy charged particles radiating in a homogeneous magnetic field, the solution and properties of the Dirac equation for magnetic fields of any strength up to 10 to the 13th power gauss, experimental difficulties encountered and overcome in generating megagauss fields, the effect of strong radiation damping for an ultrarelativistic charge in an external electromagnetic field, magnetic susceptibilities of nuclei and elementary particles, and Compton scattering in strong external electromagnetic fields. Other papers examine static uniform electric and magnetic polarizabilities of the vacuum in arbitrarily strong magnetic fields, quantum-mechanical processes in neutron stars, basic ideas of mean-field magnetohydrodynamics, helical MHD turbulence, relations between cosmic and laboratory plasma physics, and insights into the nature of magnetism provided by relativity and cosmology. Individual items are announced in this issue.

  6. PREFACE: 2nd International Workshop on Theoretical and Computational Physics (IWTCP-2): Modern Methods and Latest Results in Particle Physics, Nuclear Physics and Astrophysics and the 39th National Conference on Theoretical Physics (NCTP-39)

    NASA Astrophysics Data System (ADS)

    Hoang, Trinh Xuan; Ky, Nguyen Anh; Lan, Nguyen Tri; Viet, Nguyen Ai

    2015-06-01

    This volume contains selected papers presented at the 2nd International Workshop on Theoretical and Computational Physics (IWTCP-2): Modern Methods and Latest Results in Particle Physics, Nuclear Physics and Astrophysics and the 39th National Conference on Theoretical Physics (NCTP-39). Both the workshop and the conference were held from 28th - 31st July 2014 in Dakruco Hotel, Buon Ma Thuot, Dak Lak, Vietnam. The NCTP-39 and the IWTCP-2 were organized under the support of the Vietnamese Theoretical Physics Society, with a motivation to foster scientific exchanges between the theoretical and computational physicists in Vietnam and worldwide, as well as to promote high-standard level of research and education activities for young physicists in the country. The IWTCP-2 was also an External Activity of the Asia Pacific Center for Theoretical Physics (APCTP). About 100 participants coming from nine countries participated in the workshop and the conference. At the IWTCP-2 workshop, we had 16 invited talks presented by international experts, together with eight oral and ten poster contributions. At the NCTP-39, three invited talks, 15 oral contributions and 39 posters were presented. We would like to thank all invited speakers, participants and sponsors for making the workshop and the conference successful. Trinh Xuan Hoang, Nguyen Anh Ky, Nguyen Tri Lan and Nguyen Ai Viet

  7. Physics, astronomy, and astrophysics: A numerical study of the black hole plus Brill wave spacetime

    NASA Astrophysics Data System (ADS)

    Bernstein, David Harold

    We investigate solutions of the vacuum Einstein equations in space-times containing a single Einstein-Rosen bridge. The physical and geometrical content of the Schwarzschild solution is analyzed in a number of different spacetime coordinate systems, some well known and some new. In addition, the accuracy of numerical schemes for solving the evolution equations is studied. The same numerical methods are then used to construct axisymmetric solutions which correspond to a Schwarzschild black hole in the presence of time symmetric gravitational radiation (which we call 'Brill waves'). The initial data, evolution of perturbations, and evolution of large amplitude waves are discussed in detail. The initial data is found to display some of the properties of similar data sets studied in the past. The perturbation solutions are shown to agree with known black hole perturbation theory results to within a few percent. Some new results about the apparent horizon in the perturbed Schwarzschild solution are displayed (e.g., the apparent horizon undergoes oscillations similar to that of a damped harmonic oscillator). In addition, traditional radiative variables used in numerical relativity are matched against the known radiative variables of perturbation theory and good agreement is reached in most cases. The large amplitude wave space times are then studied by examining the behavior of the apparent horizon and by investigating the nature of the waveforms as the amplitude is increased into the 'nonlinear' regime. It is found that the apparent horizon may undergo severe distortions by collision with a large amplitude wave. The total mass loss in radiation is studied and it is shown that in some cases a large amount of the initial radiation may escape to null infinity.

  8. Study of Seismic Activity Using Geophysical and Radio Physical Equipment for Observation

    NASA Astrophysics Data System (ADS)

    Kvavadze, N.; Tsereteli, N. S.

    2015-12-01

    One of the most dangerous and destructive natural hazards are earthquakes, which is confirmed by recent earthquakes such as Nepal 2015, Japan and Turkey 2011. Because of this, study of seismic activity is important. Studying any process, it is necessary to use different methods of observation, which allows us to increase accuracy of obtained data. Seismic activity is a complex problem and its study needs different types of observation methods. Two main problems of seismic activity study are: reliable instrumental observations and earthquake short-term predictions. In case of seismic risks it is necessary to have reliable accelerometer data. One of the most promising field in earthquake short-term prediction is very low frequency (VLF) electromagnetic wave propagation in ionosphere observation. To study Seismic activity of Caucasus region, was created observation complex using Accelerometer, Velocimeter and VLF electromagnetic waves received from communication stations (located in different area of the world) reflected from low ionosphere. System is created and operates at Tbilisi State University Ionosphere Observatory, near Tbilisi in Tabakhmela 42.41'70 N, 44.80'92 E, Georgia. Data obtained is sent to a local server located at M. Nodia Institute of Geophysics, TSU, for storage and processing. Diagram for complex is presented. Also data analysis methods were created and preliminary processing was done. In this paper we present some of the results: Earthquake data from ionosphere observations as well as local earthquakes recorded with accelerometer and velocimeter. Complex is first in 6 that will be placed around Georgia this year. We plan on widening network every year.

  9. Experimental Investigations of the Physical and Optical Properties of Individual Micron/Submicron-Size Dust Grains in Astrophysical Environments

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Tankosic, D.; LeClair, A.

    2014-01-01

    Dust grains constitute a significant component of matter in the universe, and play an important and crucial role in the formation and evolution of the stellar/planetary systems in interstellar dust clouds. Knowledge of physical and optical properties of dust grains is required for understanding of a variety of processes in astrophysical and planetary environments. The currently available and generally employed data on the properties of dust grains is based on bulk materials, with analytical models employed to deduce the corresponding values for individual small micron/submicron-size dust grains. However, it has been well-recognized over a long period, that the properties of individual smallsize dust grains may be very different from those deduced from bulk materials. This has been validated by a series of experimental investigations carried out over the last few years, on a laboratory facility based on an Electrodynamic Balance at NASA, which permits levitation of single small-size dust grains of desired composition and size, in vacuum, in simulated space environments. In this paper, we present a brief review of the results of a series of selected investigations carried out on the analogs of interstellar and planetary dust grains, as well as dust grains obtained by Apollo-l1-17 lunar missions. The selected investigations, with analytical results and discussions, include: (a) Direct measurements of radiation on individual dust grains (b) Rotation and alignments of dust grains by radiative torque (c) Charging properties of dust grains by: (i) UV Photo-electric emissions (ii) Electron Impact. The results from these experiments are examined in the light of the current theories of the processes involved.

  10. Nuclear astrophysics

    SciTech Connect

    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.

  11. Nuclear astrophysics

    SciTech Connect

    Haxton, W.C.

    1992-12-31

    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.

  12. Laboratory Astrophysics White Paper

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy; Federman, Steve; Kwong, Victor; Salama, Farid; Savin, Daniel; Stancil, Phillip; Weingartner, Joe; Ziurys, Lucy

    2006-01-01

    Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomical and planetary research and will remain so for many generations to come. From the level of scientific conception to that of the scientific return, it is our understanding of the underlying processes that allows us to address fundamental questions regarding the origins and evolution of galaxies, stars, planetary systems, and life in the cosmos. In this regard, laboratory astrophysics is much like detector and instrument development at NASA and NSF; these efforts are necessary for the astronomical research being funded by the agencies. The NASA Laboratory Astrophysics Workshop met at the University of Nevada, Las Vegas (UNLV) from 14-16 February, 2006 to identify the current laboratory data needed to support existing and future NASA missions and programs in the Astrophysics Division of the Science Mission Directorate (SMD). Here we refer to both laboratory and theoretical work as laboratory astrophysics unless a distinction is necessary. The format for the Workshop involved invited talks by users of laboratory data, shorter contributed talks and poster presentations by both users and providers that highlighted exciting developments in laboratory astrophysics, and breakout sessions where users and providers discussed each others' needs and limitations. We also note that the members of the Scientific Organizing Committee are users as well as providers of laboratory data. As in previous workshops, the focus was on atomic, molecular, and solid state physics.

  13. The use and misuse of statistical analyses. [in geophysics and space physics

    NASA Technical Reports Server (NTRS)

    Reiff, P. H.

    1983-01-01

    The statistical techniques most often used in space physics include Fourier analysis, linear correlation, auto- and cross-correlation, power spectral density, and superposed epoch analysis. Tests are presented which can evaluate the significance of the results obtained through each of these. Data presented without some form of error analysis are frequently useless, since they offer no way of assessing whether a bump on a spectrum or on a superposed epoch analysis is real or merely a statistical fluctuation. Among many of the published linear correlations, for instance, the uncertainty in the intercept and slope is not given, so that the significance of the fitted parameters cannot be assessed.

  14. VINE-A NUMERICAL CODE FOR SIMULATING ASTROPHYSICAL SYSTEMS USING PARTICLES. I. DESCRIPTION OF THE PHYSICS AND THE NUMERICAL METHODS

    SciTech Connect

    Wetzstein, M.; Nelson, Andrew F.; Naab, T.; Burkert, A.

    2009-10-01

    We present a numerical code for simulating the evolution of astrophysical systems using particles to represent the underlying fluid flow. The code is written in Fortran 95 and is designed to be versatile, flexible, and extensible, with modular options that can be selected either at the time the code is compiled or at run time through a text input file. We include a number of general purpose modules describing a variety of physical processes commonly required in the astrophysical community and we expect that the effort required to integrate additional or alternate modules into the code will be small. In its simplest form the code can evolve the dynamical trajectories of a set of particles in two or three dimensions using a module which implements either a Leapfrog or Runge-Kutta-Fehlberg integrator, selected by the user at compile time. The user may choose to allow the integrator to evolve the system using individual time steps for each particle or with a single, global time step for all. Particles may interact gravitationally as N-body particles, and all or any subset may also interact hydrodynamically, using the smoothed particle hydrodynamic (SPH) method by selecting the SPH module. A third particle species can be included with a module to model massive point particles which may accrete nearby SPH or N-body particles. Such particles may be used to model, e.g., stars in a molecular cloud. Free boundary conditions are implemented by default, and a module may be selected to include periodic boundary conditions. We use a binary 'Press' tree to organize particles for rapid access in gravity and SPH calculations. Modules implementing an interface with special purpose 'GRAPE' hardware may also be selected to accelerate the gravity calculations. If available, forces obtained from the GRAPE coprocessors may be transparently substituted for those obtained from the tree, or both tree and GRAPE may be used as a combination GRAPE/tree code. The code may be run without

  15. Vine—A Numerical Code for Simulating Astrophysical Systems Using Particles. I. Description of the Physics and the Numerical Methods

    NASA Astrophysics Data System (ADS)

    Wetzstein, M.; Nelson, Andrew F.; Naab, T.; Burkert, A.

    2009-10-01

    We present a numerical code for simulating the evolution of astrophysical systems using particles to represent the underlying fluid flow. The code is written in Fortran 95 and is designed to be versatile, flexible, and extensible, with modular options that can be selected either at the time the code is compiled or at run time through a text input file. We include a number of general purpose modules describing a variety of physical processes commonly required in the astrophysical community and we expect that the effort required to integrate additional or alternate modules into the code will be small. In its simplest form the code can evolve the dynamical trajectories of a set of particles in two or three dimensions using a module which implements either a Leapfrog or Runge-Kutta-Fehlberg integrator, selected by the user at compile time. The user may choose to allow the integrator to evolve the system using individual time steps for each particle or with a single, global time step for all. Particles may interact gravitationally as N-body particles, and all or any subset may also interact hydrodynamically, using the smoothed particle hydrodynamic (SPH) method by selecting the SPH module. A third particle species can be included with a module to model massive point particles which may accrete nearby SPH or N-body particles. Such particles may be used to model, e.g., stars in a molecular cloud. Free boundary conditions are implemented by default, and a module may be selected to include periodic boundary conditions. We use a binary "Press" tree to organize particles for rapid access in gravity and SPH calculations. Modules implementing an interface with special purpose "GRAPE" hardware may also be selected to accelerate the gravity calculations. If available, forces obtained from the GRAPE coprocessors may be transparently substituted for those obtained from the tree, or both tree and GRAPE may be used as a combination GRAPE/tree code. The code may be run without

  16. Recognition of compact astrophysical objects

    NASA Technical Reports Server (NTRS)

    Ogelman, H. (Editor); Rothschild, R. (Editor)

    1977-01-01

    NASA's Laboratory for High Energy Astrophysics and the Dept. of Physics and Astrophysics at the Univ. of Md. collaberated on a graduate level course with this title. This publication is an edited version of notes used as the course text. Topics include stellar evolution, pulsars, binary stars, X-ray signatures, gamma ray sources, and temporal analysis of X-ray data.

  17. Simultaneous physical retrieval of Martian geophysical parameters using Thermal Emission Spectrometer spectra: the φ-MARS algorithm.

    PubMed

    Liuzzi, Giuliano; Masiello, Guido; Serio, Carmine; Fonti, Sergio; Mancarella, Francesca; Roush, Ted L

    2015-03-20

    In this paper, we present a new methodology for the simultaneous retrieval of surface and atmospheric parameters of Mars. The methodology is essentially based on similar codes implemented for high-resolution instruments looking at Earth, supported by a statistical retrieval procedure used to initialize the physical retrieval algorithm with a reliable first guess of the atmospheric parameters. The methodology has been customized for the Thermal Emission Spectrometer (TES), which is a low-resolution interferometer. However, with minor changes to the forward and inverse modules, it is applicable to any instrument looking at Mars, and with particular effectiveness to high-resolution instruments. The forward module is a monochromatic radiative transfer model with the capability to calculate analytical Jacobians of any desired geophysical parameter. In the present work, we describe the general methodology and its application to a large sample of TES spectra. Results are drawn for the case of surface temperature and emissivity, atmospheric temperature profile, water vapor, and dust and ice mixing ratios. Comparison with climate models and other TES data analyses show very good agreement and consistency.

  18. Astrophysics: An Integrative Course

    ERIC Educational Resources Information Center

    Gutsche, Graham D.

    1975-01-01

    Describes a one semester course in introductory stellar astrophysics at the advanced undergraduate level. The course aims to integrate all previously learned physics by applying it to the study of stars. After a brief introductory section on basic astronomical measurements, the main topics covered are stellar atmospheres, stellar structure, and…

  19. ON THE PHYSICS OF GALVANIC SOURCE ELECTROMAGNETIC GEOPHYSICAL METHODS FOR TERRESTRIAL AND MARINE EXPLORATION

    SciTech Connect

    David Alumbaugh and Evan Um

    2007-06-27

    A numerical study was conducted to investigate the governing physics of galvanic source electromagnetic (EM) methods for terrestrial and marine exploration scenarios. The terrestrial exploration scenario involves the grounded electric dipole source EM (GESTEM) method and the examination of how the GESTEM method can resolve a thin resistive layer representing underground gas and/or hydrocarbon storage. Numerical modeling studies demonstrate that the loop transient EM (TEM) and magnetotelluric (MT) methods are insensitive to a thin horizontal resistor at depth because they utilize horizontal currents. In contrast to these standard EM methods, the GESTEM method generates both vertical and horizontal transient currents. The vertical transient current interacts with a thin horizontal resistor and causes charge buildup on its surface. These charges produce a measurable perturbation in the surface electric field at early time. The degree of perturbation depends on source waveform. When the GESTEM method is energized with step-off waveform, the perturbation due to a thin horizontal resistor is small. This is because the step-off waveform mainly consists of low frequency signals. An alternative is taking the time-derivative of the step-off responses to approximate the impulse response which includes higher frequency signals. In order to improve degree of perturbation especially due to a localized small 3-D resistor, the diffusion angle of the vertical transient current, 45 should be considered to make vertical currents coupled to a resistive target efficiently. The major drawback of the GESTEM method lies in the fact that GESTEM sounding can not be interpreted using 1-D inversion schemes if there is near-surface inhomogeneity. The marine exploration scenario investigates the physics of marine frequency-domain controlled source EM (FDCSEM) and time-domain controlled source EM (TDCSEM) methods to explore resistive hydrocarbon reservoirs in marine environments. Unlike the

  20. Twitter use in physics conferences.

    PubMed

    Webb, Stephen

    An analysis of Twitter use in 116 conferences suggests that the service is used more extensively at PACS10 conferences (those devoted to the physics of elementary particles and fields) and PACS90 conferences (those devoted to geophysics, astronomy, and astrophysics) than at conferences in other fields of physics. Furthermore, Twitter is used in a qualitatively different manner. A possible reason for these differences is discussed.

  1. Problems in theoretical physics and astrophysics: Collection of articles in celebration of the 70th birthday of V. L. Ginzburg

    NASA Astrophysics Data System (ADS)

    Keldysh, L. V.; Fainberg, V. Ia.

    Papers are presented on such topics as the quantum theory of many particles, astrophysics, and the theory of elementary particles. Particular attention is given to mechanisms of spontaneous and stimulated emission from relativistic electron beams; superconductivity in metals with strong disorder; heavy-fermion systems; cosmic-ray components at high energies; a classical model of the axisymmetric pulsar magnetosphere; the origin and cosmogonic implications of seed magnetic fields; and string theory and effective field-theoretic action.

  2. Black holes, formation of structure, and extreme physics: the present and future of X-ray astrophysics

    NASA Astrophysics Data System (ADS)

    Kraft, Ralph; Bautz, Mark

    2017-01-01

    X-ray astrophysics lies at the conjunction of many of the big picture questions we have about our Universe. We detect X-rays from supermassive black holes when the Universe was 7% of its present age, just after the formation of the first galaxies. Most of the baryons in the Universe are in clusters or in the filaments between collapsed structures heated to X-ray emitting temperatures. X-ray studies of the evolution of these collapsed structures provide strong constraints on cosmological parameters. Studies by future X-ray observatories of this hot filamentary gas between clusters and of halos of galaxies will provide unique windows in the processes of the early universe and formation of structure. In this presentation, we discuss the current state of X-ray astrophysics. We will present the status of and recent science highlights from the current generation of X-ray observatories. We will outline the scientific potential for missions that will soon be launched including NICER, eRosita, and a potential refly of the Hitomi mission, as well as longer term missions such as the European L2 Athena mission. Finally, we will summarize the status of the X-ray Surveyor, one of the four large mission concepts under study prior to the 2020 Astrophysics Decadal Review.

  3. Cognitive Astrophysics

    NASA Astrophysics Data System (ADS)

    Madore, Barry F.

    2012-09-01

    Cognitive Astrophysics works at the cusp between Cognitive Science and Astrophysics, drawing upon lessons learned in the Philosophy of Science, Linguistics and Artificial Intelligence. We will introduce and illustrate the concept of ``Downward Causation,'' common in philosophical discussions, but either unknown to or disdained by most physicists. A clear example operating on cosmological scales involving the origin of large-scale structure will be given. We will also make the case that on scales exceeding most laboratory experiments, self-gravitating matter can be considered to be in a ``fifth state'', characterized primarily by its negative specific heat, as first recognized by Lynden-Bell and Lynden-Bell (1977, MNRAS, 181, 405). Such systems increase their temperature as they lose energy. Numerous examples will be given and discussed.

  4. Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The four geophysical methods predominantly used for agricultural purposes are resistivity, electromagnetic induction, ground penetrating radar (GPR), and time domain reflectometry (TDR). Resistivity and electromagnetic induction methods are typically employed to map lateral variations of apparent so...

  5. Exploration Geophysics

    ERIC Educational Resources Information Center

    Espey, H. R.

    1977-01-01

    Describes geophysical techniques such as seismic, gravity, and magnetic surveys of offshare acreage, and land-data gathering from a three-dimensional representation made from closely spaced seismic lines. (MLH)

  6. Exploration Geophysics

    ERIC Educational Resources Information Center

    Savit, Carl H.

    1978-01-01

    Expansion of activity and confirmation of new technological directions characterized several fields of exploration geophysics in 1977. Advances in seismic-reflection exploration have been especially important. (Author/MA)

  7. Preliminary Physical Stratigraphy and Geophysical Data of the USGS Hope Plantation Core (BE-110), Bertie County, North Carolina

    USGS Publications Warehouse

    Weems, Robert E.; Seefelt, Ellen L.; Wrege, Beth M.; Self-Trail, Jean M.; Prowell, David C.; Durand, Colleen; Cobbs, Eugene F.; McKinney, Kevin C.

    2007-01-01

    Introduction In March and April, 2004, the U.S. Geological Survey (USGS), in cooperation with the North Carolina Geological Survey (NCGS) and the Raleigh Water Resources Discipline (WRD), drilled a stratigraphic test hole and well in Bertie County, North Carolina (fig. 1). The Hope Plantation test hole (BE-110-2004) was cored on the property of Hope Plantation near Windsor, North Carolina. The drill site is located on the Republican 7.5 minute quadradrangle at lat 36?01'58'N., long 78?01'09'W. (decimal degrees 36.0329 and 77.0192) (fig. 2). The altitude of the site is 48 ft above mean sea level as determined by Paulin Precise altimeter. This test hole was continuously cored by Eugene F. Cobbs, III and Kevin C. McKinney (USGS) to a total depth of 1094.5 ft. Later, a ground water observation well was installed with a screened interval between 315-329 feet below land surface (fig. 3). Upper Triassic, Lower Cretaceous, Upper Cretaceous, Tertiary, and Quaternary sediments were recovered from the site. The core is stored at the NCGS Coastal Plain core storage facility in Raleigh, North Carolina. In this report, we provide the initial lithostratigraphic summary recorded at the drill site along with site core photographs, data from the geophysical logger, calcareous nannofossil biostratigraphic correlations (Table 1) and initial hydrogeologic interpretations. The lithostratigraphy from this core can be compared to previous investigations of the Elizabethtown corehole, near Elizabethtown, North Carolina in Bladen County (Self-Trail, Wrege, and others, 2004), the Kure Beach corehole, near Wilmington, North Carolina in New Hanover County (Self-Trail, Prowell, and Christopher, 2004), the Esso #1, Esso #2, Mobil #1 and Mobil #2 cores in the Albermarle and Pamlico Sounds (Zarra, 1989), and the Cape Fear River outcrops in Bladen County (Farrell, 1998; Farrell and others, 2001). This core is the third in a series of planned benchmark coreholes that will be used to elucidate the

  8. The Asteroid Impact Mission (AIM): Studying the geophysics of small binaries, measuring asteroid deflection and studying impact physics

    NASA Astrophysics Data System (ADS)

    Kueppers, Michael; Michel, Patrick; AIM Team

    2016-10-01

    Binary asteroids and their formation mechanisms are of particular interest for understanding the evolution of the small bodies in the solar system. Also, hazards to Earth from impact of near-Earth asteroids and their mitigation have drawn considerable interest over the last decades.Those subjects are both addressed by ESA's Asteroid Impact mission, which is part of the Asteroid Impact & Deflection Assessment (AIDA) currently under study in collaboration between NASA and ESA. NASA's DART mission will impact a projectile into the minor component of the binary near-Earth asteroid (65803) Didymos in 2022. The basic idea is to demonstrate the effect of the impact on the orbital period of the secondary around the primary. ESA's AIM will monitor the Didymos system for several months around the DART impact time.AIM will be launched in aurumn 2020. It is foreseen to arrive at Didymos in April 2022. The mission takes advantage of a close approach of Didymos to Earth. The next opportunity would arise in 2040 only.AIM will stay near Didymos for approximately 6 months. Most of the time it will be placed on the illuminated side of the system, at distances of approximately 35 km and 10 km. AIM is expected to move away from Didymos for some time around the DART impact.The reference payload for AIM includes two visual imagers, a hyperspectral camera, a lidar, a thermal infrared imager, a monostatic high frequency radar, and a bistatic low frequency radar. In addition, AIM will deploy a small lander on the secondary asteroid, and two cubesats that will be used for additional, more risky investigations close to or on the surface of the asteroid.Major contributions from AIM are expected in the study of the geophysics of small asteroids (including for the first time, radar measurements of an interior structure), the formation of binary asteroids, the momentum enhancement factor from the DART impact (through measuring the mass and the change of orbit of the seondary), and impact physics

  9. Computational astrophysical fluid dynamics

    NASA Technical Reports Server (NTRS)

    Norman, Michael L.; Clarke, David A.; Stone, James M.

    1991-01-01

    The field of astrophysical fluid dynamics (AFD) is described as an emerging discipline which derives historically from both the theory of stellar evolution and space plasma physics. The fundamental physical assumption behind AFD is that fluid equations of motion accurately describe the evolution of plasmas on scales that are large in comparison with particle interaction length scales. Particular attention is given to purely fluid models of large-scale astrophysical plasmas. The role of computer simulation in AFD research is also highlighted and a suite of general-purpose application codes for AFD research is discussed. The codes are called ZEUS-2D and ZEUS-3D and solve the equations of AFD in two and three dimensions, respectively, in several coordinate geometries for general initial and boundary conditions. The topics of bipolar outflows from protostars, galactic superbubbles and supershells, and extragalactic radio sources are addressed.

  10. Extreme Scale Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre

    2009-11-01

    We live in extraordinary times. With increasingly sophisticated observatories opening up new vistas on the universe, astrophysics is becoming more complex and data-driven. The success in understanding astrophysical systems that are inherently multi-physical, nonlinear systems demands realism in our models of the phenomena. We cannot hope to advance the realism of these models to match the expected sophistication of future observations without extreme-scale computation. Just one example is the advent of gravitational wave astronomy. Detectors like LIGO are about to make the first ever detection of gravitational waves. The gravitational waves are produced during violent events such as the merger of two black holes. The detection of these waves or ripples in the fabric of spacetime is a formidable undertaking, requiring innovative engineering, powerful data analysis tools and careful theoretical modeling. I will discuss the computational and theoretical challenges ahead in our new understanding of physics and astronomy where gravity exhibits its strongest grip on our spacetime.

  11. Augmented Reality in astrophysics

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Shingles, Luke J.

    2013-09-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss possible future trends for Augmented Reality applications in astrophysics, and explore the current limitations associated with the technology. This Augmented Article, the first of its kind, is designed to allow the reader to directly experiment with this technology.

  12. Frontier Research in Astrophysics

    NASA Astrophysics Data System (ADS)

    Giovanelli, Franco; Sabau-Graziati, Lola

    We want to join about 90 colleagues from the whole world involved in various topics of modern Astrophysics and Particle Physics in order to discuss the most recent experimental and theoretical results for an advance in the comprehension of the Physics governing our Universe. For reaching the aim of the workshop the idea is to use ground- and space-based experimental developments, theoretical developments AND the coming out science results which have already resulted OR WILL result into high impact science papers. 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, Cataclysmic Variables and Novae, Supernovae and SNRs, X-Ray Binary Systems, Pulsars, Black Holes, Gamma-Ray Sources, Nucleosynthesis. Future Physics and Astrophysics: Ongoing and Planned Ground- and Space-based Experiments. The workshop will include few 40-minute general review talks to introduce the current problems, and typically 20-minute talks discussing new experimental and theoretical results. A series of 15-minute talks will discuss the ongoing and planned ground- and space-based experiments. The cadence of the workshop will be biennial. The participation will be only by invitation. Editors: Franco Giovannelli and Lola Sabau-Graziati

  13. Astrophysics at the Highest Energy Frontiers

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    I discuss recent advances being made in the physics and astrophysics of cosmic rays and cosmic gamma-rays at the highest observed energies as well as the related physics and astrophysics of very high energy cosmic neutrinos. I also discuss the connections between these topics.

  14. Astrophysical fluid dynamics

    NASA Astrophysics Data System (ADS)

    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.

  15. Geophysical Institute. Biennial report, 1993-1994

    SciTech Connect

    1996-01-01

    The 1993-1994 Geophysical Institute Biennial Report was published in November 1995 by the Geophysical Institute of the University of Alaska Fairbanks. It contains an overview of the Geophysical Institute, the Director`s Note, and research presentations concerning the following subjects: Scientific Predictions, Space Physics, Atmospheric Sciences, Snow, Ice and Permafrost, Tectonics and Sedimentation, Seismology, Volcanology, Remote Sensing, and other projects.

  16. Computational astrophysics

    NASA Technical Reports Server (NTRS)

    Miller, Richard H.

    1987-01-01

    Astronomy is an area of applied physics in which unusually beautiful objects challenge the imagination to explain observed phenomena in terms of known laws of physics. It is a field that has stimulated the development of physical laws and of mathematical and computational methods. Current computational applications are discussed in terms of stellar and galactic evolution, galactic dynamics, and particle motions.

  17. Geophysics News 1990

    NASA Astrophysics Data System (ADS)

    Cole, Stephen

    The last two years have witnessed many major geophysical events such as the Loma Prieta earthquake, new insights into plate motions, new seismic and mid-ocean ridge observational programs, and new views of a distant planet. AGU's Public Information Committee, chaired by Debra Knopman of the U.S. Geological Survey, was asked by the American Institute of Physics to prepare a series of articles on the major topics in geophysics for publication in Physics News in 1990. Several of those papers did appear in the AIP publication. In the absence of a comparable publication devoted solely to a summary of news in geophysics, AGU is publishing the 20 articles solicited by the Public Information Committee as a booklet, Geophysics News 1990, that is being distributed to the media. The articles are also being published in Eos starting with this issue and continuing for the next several weeks. The topics covered in these articles range from the world's deepest rocks to the powerful blast waves from major solar flares.

  18. Astrophysical Magnetic Fields and Topics in Galaxy Formation

    NASA Technical Reports Server (NTRS)

    Field, George B.

    1997-01-01

    The grant was used to support theoretical research on a variety of astro-physical topics falling broadly into those described by the proposal: galaxy formation, astrophysical magnetic fields, magnetized accretion disks in AGN, new physics, and other astrophysical problems. Work accomplished; references are to work authored by project personel.

  19. Molecular Astrophysics

    NASA Astrophysics Data System (ADS)

    Hartquist, T. W.

    2005-07-01

    Part I. Molecular Clouds and the Distribution of Molecules in the Milky Way and Other Galaxies: 1. Molecular clouds in the Milky Way P. Friberg and A. Hjalmarson; 2. Molecules in galaxies L. Blitz; Part II. Diffuse Molecular Clouds: 3. Diffuse cloud chemistry E. F. Van Dishoeck; 4. Observations of velocity and density structure in diffuse clouds W. D. Langer; 5. Shock chemistry in diffuse clouds T. W. Hartquist, D. R. Flower and G. Pineau des Forets; Part III. Quiescent Dense Clouds: 6. Chemical modelling of quiescent dense interstellar clouds T. J. Millar; 7. Interstellar grain chemistry V. Buch; 8. Large molecules and small grains in astrophysics S. H. Lepp; Part IV. Studies of Molecular Processes: 9. Molecular photoabsorption processes K. P. Kirby; 10. Interstellar ion chemistry: laboratory studies D. Smith, N. G. Adams and E. E. Ferguson; 11. Theoretical considerations on some collisional processes D. R. Bates; 12. Collisional excitation processes E. Roueff; 13. Neutral reactions at Low and High Temperatures M. M. Graff; Part V. Atomic Species in Dense Clouds: 14. Observations of atomic species in dense clouds G. J. Melnick; 15. Ultraviolet radiation in molecular clouds W. G. Roberge; 16. Cosmic ray induced photodissociation and photoionization of interstellar molecules R. Gredel; 17. Chemistry in the molecular cloud Barnard 5 S. B. Charnley and D. A. Williams; 18. Molecular cloud structure, motions, and evolution P. C. Myers; Part VI. H in Regions of Massive Star Formation: 19. Infrared observations of line emission from molecular hydrogen T. R. Geballe; 20. Shocks in dense molecular clouds D. F. Chernoff and C. F. McKee; 21. Dissociative shocks D. A. Neufeld; 22. Infrared molecular hydrogen emission from interstellar photodissociation regions A. Sternberg; Part VII. Molecules Near Stars and in Stellar Ejecta: 23. Masers J. M. Moran; 24. Chemistry in the circumstellar envelopes around mass-losing red giants M. Jura; 25. Atoms and molecules in supernova 1987a R

  20. The Nuclear Astrophysics Explorer

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.; Teegarden, B. J.; Gehrels, N.; Mahoney, W. A.

    1989-01-01

    The Nuclear Astrophysics Explorer was proposed in 1986 for NASA's Explorer Concept Study Program by an international collaboration of 25 scientists from nine institutions. The one-year feasibility study began in June 1988. The Nuclear Astrophysics Explorer would obtain high resolution observations of gamma-ray lines, E/Delta E about 1000, at a sensitivity of about 0.000003 ph/sq cm s, in order to study fundamental problems in astrophysics such as nucleosynthesis, supernovae, neutron star and black-hole physics, and particle acceleration and interactions. The instrument would operate from 15 keV to 10 Mev and use a heavily shielded array of nine cooled Ge spectrometers in a very low background configuration. Its 10 deg FWHM field of view would contain a versatile coded mask system which would provide two-dimensional imaging with 4 deg resolution, one-dimensional imaging with 2 deg resolution, and efficiendt measurements of diffuse emission. An unshielded Ge spectrometer would obtain wide-field measurements of transient gamma-ray sources. The earliest possible mission would begin in 1995.

  1. Texas Symposium on Relativistic Astrophysics, 11th, Austin, TX, December 12-17, 1982, Proceedings

    NASA Technical Reports Server (NTRS)

    Evans, D. S. (Editor)

    1984-01-01

    Various papers on relativistic astrophysics are presented. The general subjects addressed include: particle physics and astrophysics, general relativity, large-scale structure, big bang cosmology, new-generation telescopes, pulsars, supernovae, high-energy astrophysics, and active galaxies.

  2. Turbulent mixing and beyond: non-equilibrium processes from atomistic to astrophysical scales

    PubMed Central

    Abarzhi, S. I.; Gauthier, S.; Sreenivasan, K. R.

    2013-01-01

    Turbulent mixing is a source of paradigm problems in physics, engineering and mathematics. Beyond this important interdisciplinary role, it has immense consequences for a broad range of applications in astrophysics, geophysics, climate and large-scale energy systems. In two volumes, we summarize and provide a perspective on the topic through some 20 articles focusing on turbulent mixing and beyond. The volumes are grouped, somewhat loosely, into those associated with fundamental aspects of turbulence and those specific to Rayleigh–Taylor turbulent mixing. PMID:23185062

  3. 'Hot Topics' in Astrophysics

    NASA Technical Reports Server (NTRS)

    Maran, Stephen P.

    2000-01-01

    Three current topics in astrophysics are described here on the occasion of the joint meeting of the American Association of Physics Teachers and the American Astronomical Society (Jan. 7-11, 2001, San Diego, Calif.). Many equally exciting topics--ranging from the dozens of newly discovered planets of sunlike stars to evidence suggesting that the expansion of the universe is accelerating--could have been chosen. The topics discussed are: (1) the habitability of Mars, (2) black holes, galaxy bulges, and the X-ray background, and (3) the greatest explosions since the Big Bang.

  4. Physical bases of the generation of short-term earthquake precursors: A complex model of ionization-induced geophysical processes in the lithosphere-atmosphere-ionosphere-magnetosphere system

    NASA Astrophysics Data System (ADS)

    Pulinets, S. A.; Ouzounov, D. P.; Karelin, A. V.; Davidenko, D. V.

    2015-07-01

    This paper describes the current understanding of the interaction between geospheres from a complex set of physical and chemical processes under the influence of ionization. The sources of ionization involve the Earth's natural radioactivity and its intensification before earthquakes in seismically active regions, anthropogenic radioactivity caused by nuclear weapon testing and accidents in nuclear power plants and radioactive waste storage, the impact of galactic and solar cosmic rays, and active geophysical experiments using artificial ionization equipment. This approach treats the environment as an open complex system with dissipation, where inherent processes can be considered in the framework of the synergistic approach. We demonstrate the synergy between the evolution of thermal and electromagnetic anomalies in the Earth's atmosphere, ionosphere, and magnetosphere. This makes it possible to determine the direction of the interaction process, which is especially important in applications related to short-term earthquake prediction. That is why the emphasis in this study is on the processes proceeding the final stage of earthquake preparation; the effects of other ionization sources are used to demonstrate that the model is versatile and broadly applicable in geophysics.

  5. High Energy Density Laboratory Astrophysics

    SciTech Connect

    Remington, B A

    2004-11-11

    High-energy-density (HED) physics refers broadly to the study of macroscopic collections of matter under extreme conditions of temperature and density. The experimental facilities most widely used for these studies are high-power lasers and magnetic-pinch generators. The HED physics pursued on these facilities is still in its infancy, yet new regimes of experimental science are emerging. Examples from astrophysics include work relevant to planetary interiors, supernovae, astrophysical jets, and accreting compact objects (such as neutron stars and black holes). In this paper, we will review a selection of recent results in this new field of HED laboratory astrophysics and provide a brief look ahead to the coming decade.

  6. IGI (the Italian Grid initiative) and its impact on the Astrophysics community

    NASA Astrophysics Data System (ADS)

    Pasian, F.; Vuerli, C.; Taffoni, G.

    IGI - the Association for the Italian Grid Infrastructure - has been established as a consortium of 14 different national institutions to provide long term sustainability to the Italian Grid. Its formal predecessor, the Grid.it project, has come to a close in 2006; to extend the benefits of this project, IGI has taken over and acts as the national coordinator for the different sectors of the Italian e-Infrastructure present in EGEE. IGI plans to support activities in a vast range of scientificdisciplines - e.g. Physics, Astrophysics, Biology, Health, Chemistry, Geophysics, Economy, Finance - and any possible extensions to other sectors such as Civil Protection, e-Learning, dissemination in Universities and secondary schools. Among these, the Astrophysics community is active as a user, by porting applications of various kinds, but also as a resource provider in terms of computing power and storage, and as middleware developer.

  7. Astrophysical implications of periodicity

    NASA Technical Reports Server (NTRS)

    Muller, Richard 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.

  8. Flexible, Mastery-Oriented Astrophysics Sequence.

    ERIC Educational Resources Information Center

    Zeilik, Michael, II

    1981-01-01

    Describes the implementation and impact of a two-semester mastery-oriented astrophysics sequence for upper-level physics/astrophysics majors designed to handle flexibly a wide range of student backgrounds. A Personalized System of Instruction (PSI) format was used fostering frequent student-instructor interaction and role-modeling behavior in…

  9. Nuclear theory with applications to astrophysics and particle physics. Final report, 15 January 1994--14 January 1997

    SciTech Connect

    1998-11-01

    Many of the topics discussed here are takeoff points for projects proposed later. Brief summaries are given for the following projects: (1) time-reversal violation; (2) the rare-earth r-process bump; (3) structure of weakly bound pairs; (4) neutron-proton pairing and isospin symmetry; (5) detection of galactic dark matter; (6) iodine as a solar neutrino detector; and (7) neutrino physics at LSND.

  10. Astrophysics on the Lab Bench

    ERIC Educational Resources Information Center

    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…

  11. Scaling Extreme Astrophysical Phenomena to the Laboratory

    SciTech Connect

    Remington, B A

    2007-11-01

    High-energy-density (HED) physics refers broadly to the study of macroscopic collections of matter under extreme conditions of temperature and density. The experimental facilities most widely used for these studies are high-power lasers and magnetic-pinch generators. The HED physics pursued on these facilities is still in its infancy, yet new regimes of experimental science are emerging. Examples from astrophysics include work relevant to planetary interiors, supernovae, astrophysical jets, and accreting compact objects (such as neutron stars and black holes). In this paper, we review a selection of recent results in this new field of HED laboratory astrophysics and provide a brief look ahead to the coming decade.

  12. Laboratory measurements of the physical properties of Triassic Evaporites from Central Italy and correlation with geophysical data

    NASA Astrophysics Data System (ADS)

    Trippetta, F.; Collettini, C.; Vinciguerra, S.; Meredith, P. G.

    2010-09-01

    The Triassic Evaporites (TE) of the Umbria-Marche Apennines, a sedimentary succession made up of a sequence of alternating sulphates (anhydrites and gypsum) and dolostones, represent a key lithology in terms of sealing properties and earthquake triggering. Here we: (1) report laboratory measurements of density, porosity, Vp, Vs, seismic anisotropy and permeability at effective confining pressures from 0 to 100 MPa, conducted on samples of TE collected from both outcrops and boreholes; and (2) attempt to upscale the laboratory results to larger scale geophysical investigation, such as Vp sonic logs, seismic tomography and in situ measurements of pore-fluid pressure. The average laboratory P-wave velocity is 6.0 km/s for dolostones, 4.6 km/s for gypsum-dolostones and 5.8 km/s for anhydrites, at ambient pressure. As effective confining pressure is increased up to 100 MPa, the average P-wave velocity increases to 7.0 km/s for dolostones, 5.3 km/s for gypsum and 6.4 km/s for anhydrites. Vp/Vs ratios appear to be independent of confining pressure, with average values of ˜ 1.8 to ˜ 2.2 for sulphates and ˜ 1.9 to ˜ 2.2 for dolostones, respectively, for dry and saturated conditions. All samples are characterized by very low permeability (10 -18 m 2 to 10 -21 m 2), with the higher values for gypsum-dolostones and fractured dolostones samples. The Vp profiles obtained from ultrasonic laboratory measurements match well the in situ Vp profiles measured using sonic logs. In the laboratory, the Vp/Vs ratio increases when pressurized pore fluids are present, in agreement with 4D seismic tomography that relates the increase in Vp/Vs ratio to the migration of fluids during the 1997 Umbria-Marche seismic sequence ( Mmax ˜ 6.0) that nucleates within the TE. Our low-permeability values are consistent with deep borehole measurements of high pore-fluid pressure trapped within the Triassic Evaporites.

  13. Preliminary physical stratigraphy, biostratigraphy, and geophysical data of the USGS South Dover Bridge Core, Talbot County, Maryland

    USGS Publications Warehouse

    Alemán González, Wilma B.; Powars, David S.; Seefelt, Ellen L.; Edwards, Lucy E.; Self-Trail, Jean M.; Durand, Colleen T.; Schultz, Arthur P.; McLaughlin, Peter P.

    2012-01-01

    The South Dover Bridge (SDB) corehole was drilled in October 2007 in Talbot County, Maryland. The main purpose for drilling this corehole was to characterize the Upper Cretaceous and Paleogene lithostratigraphy and biostratigraphy of the aquifers and confining units of this region. The data obtained from this core also will be used as a guide to geologic mapping and to help interpret well data from the eastern part of the Washington East 1:100,000-scale map near the town of Easton, Md. Core drilling was conducted to a depth of 700 feet (ft). The Cretaceous section was not penetrated due to technical problems during drilling. This project was funded by the U.S. Geological Survey’s (USGS) Eastern Geology and Paleoclimate Science Center (EGPSC) as part of the Geology of the Atlantic Watersheds Project; this project was carried out in cooperation with the Maryland Geological Survey (MGS) through partnerships with the Aquifer Characterization Program of the USGS’s Maryland-Delaware-District of Columbia Water Science Center and the National Cooperative Geologic Mapping Program. The SDB corehole was drilled by the USGS drilling crew in the northeastern corner of the Trappe 7.5-minute quadrangle, near the type locality of the Boston Cliffs member of the Choptank Formation. Geophysical logs (gamma ray, single point resistance, and 16-inch and 64-inch normal resistivity) were run to a depth of 527.5 ft; the total depth of 700.0 ft could not be reached because of the collapse of the lower part of the hole. Of the 700.0 ft drilled, 531.8 ft of core were recovered, representing a 76 percent core recovery. The elevation of the top of the corehole is approximately 12 ft above mean sea level; its coordinates are lat 38°44′49.34″N. and long 76°00′25.09″W. (38.74704N., 76.00697W. in decimal degrees). A groundwater monitoring well was not installed at this site. The South Dover Bridge corehole was the first corehole that will be used to better understand the geology and

  14. Observational astrophysics.

    NASA Astrophysics Data System (ADS)

    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.

  15. A review of astrophysical reconnection

    NASA Astrophysics Data System (ADS)

    Uzdensky, Dmitri

    Magnetic reconnection is a basic plasma process involving rapid rearrangement of magnetic field topology. It often leads to violent release of magnetic energy and its conversion to the plasma thermal and kinetic energy as well as nonthermal particle acceleration. It is thus believed to power numerous types of explosive phenomena both inside and outside the Solar system, including various kinds of high-energy flares. In this talk I will first give an overview of astrophysical systems where reconnection is believed to play an important role. Examples include pulsed high-energy emission in pulsar magnetospheres; gamma-ray flares in pulsar wind nebulae and AGN/blazar jets; Gamma-Ray Bursts; and giant flares in magnetar systems. I will also analyze the physical conditions of the plasma in some of these astrophysical systems and will discuss the fundamental physical differences between various astrophysical instances of magnetic reconnection and the more familiar solar and space examples of reconnection. In particular, I will demonstrate the importance of including radiative effects in order to understand astrophysical magnetic reconnection and in order to connect our theoretical models with the observed radiation signatures.

  16. 1981 Summer Study Program in Geophysical Fluid Dynamics at the Woods Hole Oceangraphic Institution Physics of Convection.

    DTIC Science & Technology

    1981-11-01

    byI Willem V. R. Malkus, Director and Florence K. Mellor, Editori I WOODS HOLE OCEANOGRAPHIC INSTITUTION Woods Hole, Massachusetts 02543 I I November...Science, U. C. - Santa Cruz Howard, Louis N. Applied Mathematics, M. I. T. Knobloch, Edgar Physics, U. C. - Berkeley Krishnamurti, Ruby Oceanography...John L. Engineering, Cornell Univ. Malkus, Willem V. R. Applied Mathematics, M. I. T. Marcus, Philip Applied Mathematics, M. I. T. Meiss, James

  17. Perspectives in numerical astrophysics:

    NASA Astrophysics Data System (ADS)

    Reverdy, V.

    2016-12-01

    In this discussion paper, we investigate the current and future status of numerical astrophysics and highlight key questions concerning the transition to the exascale era. We first discuss the fact that one of the main motivation behind high performance simulations should not be the reproduction of observational or experimental data, but the understanding of the emergence of complexity from fundamental laws. This motivation is put into perspective regarding the quest for more computational power and we argue that extra computational resources can be used to gain in abstraction. Then, the readiness level of present-day simulation codes in regard to upcoming exascale architecture is examined and two major challenges are raised concerning both the central role of data movement for performances and the growing complexity of codes. Software architecture is finally presented as a key component to make the most of upcoming architectures while solving original physics problems.

  18. Overview of the Astrophysics Data System

    NASA Technical Reports Server (NTRS)

    Good, John C.; Pomphrey, Richard B.

    1991-01-01

    The Astrophysics Division of NASA has built a geographically and logically distributed heterogeneous information system for the dissemination and coordinated multispectral analysis of data from astrophysics missions. The Astrophysics Data System (ADS) is a truly distributed system in which the data and the required processing are physically distributed. To accommodate the anticipated growth and changes in both requirements and technology, the ADS employs a server/client architecture which allows services and data to be added or replaced without having to change the basic architecture or interfaces. Current datasets accessible through the system include all the tabular astronomical data available at each of six existing astrophysics data centers. Additional data nodes, at both NASA data centers and academic institutions, will be added shortly. The future evolution of the system will be driven in large part by user services mounted both by the ADS project itself and by members of the astrophysics community.

  19. Overview of the Astrophysics Data System

    NASA Technical Reports Server (NTRS)

    Good, John C.; Pomphrey, Richard B.

    1990-01-01

    The Astrophysics Division of NASA has built a geographically- and logically-distributed heterogeneous information system for the dissemination and coordinated multispectral analysis of data from astrophysics missions. The Astrophysics Data System (ADS) is a truly distributed system in which the data and the required processing are physically distributed. To accommodate the anticipated growth and changes in both requirements and technology, the ADS employs a server/client architecture which allows services and data to be added or replaced without having to change the basic architecture or interfaces. Current datasets accessible through the system include all the tabular astronomical data available at each of six existing astrophysics data centers. Additional data nodes, at both NASA data centers and academic institutions, will be added shortly. The future evolution of the system will be driven in large part by user services mounted both by the ADS project itself and by members of the astrophysics community.

  20. History of Astrophysics in Antarctica

    NASA Astrophysics Data System (ADS)

    Indermuehle, Balthasar T.; Burton, Michael C.; Maddison, Sarah T.

    We examine the historical development of astrophysical science in Antarctica from the early 20th century until today. We find three temporally overlapping eras with each having a rather distinct beginning. These are the astrogeological era of meteorite discovery the high energy era of particle detectors and the photon astronomy era of microwave sub-mm and infrared telescopes sidelined by a few optical niche experiments. The favourable atmospheric and geophysical conditions are briefly examined followed by an account of the major experiments and a summary of their results. A scientific effectiveness analysis of the various projects is presented quantitatively and we conclude with an outlook of what is to come in the 21st century

  1. Theoretical Astrophysics at Fermilab

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Theoretical Astrophysics Group works on a broad range of topics ranging from string theory to data analysis in the Sloan Digital Sky Survey. The group is motivated by the belief that a deep understanding of fundamental physics is necessary to explain a wide variety of phenomena in the universe. During the three years 2001-2003 of our previous NASA grant, over 120 papers were written; ten of our postdocs went on to faculty positions; and we hosted or organized many workshops and conferences. Kolb and collaborators focused on the early universe, in particular and models and ramifications of the theory of inflation. They also studied models with extra dimensions, new types of dark matter, and the second order effects of super-horizon perturbations. S tebbins, Frieman, Hui, and Dodelson worked on phenomenological cosmology, extracting cosmological constraints from surveys such as the Sloan Digital Sky Survey. They also worked on theoretical topics such as weak lensing, reionization, and dark energy. This work has proved important to a number of experimental groups [including those at Fermilab] planning future observations. In general, the work of the Theoretical Astrophysics Group has served as a catalyst for experimental projects at Fennilab. An example of this is the Joint Dark Energy Mission. Fennilab is now a member of SNAP, and much of the work done here is by people formerly working on the accelerator. We have created an environment where many of these people made transition from physics to astronomy. We also worked on many other topics related to NASA s focus: cosmic rays, dark matter, the Sunyaev-Zel dovich effect, the galaxy distribution in the universe, and the Lyman alpha forest. The group organized and hosted a number of conferences and workshop over the years covered by the grant. Among them were:

  2. Optimization and geophysical inverse problems

    SciTech Connect

    Barhen, J.; Berryman, J.G.; Borcea, L.; Dennis, J.; de Groot-Hedlin, C.; Gilbert, F.; Gill, P.; Heinkenschloss, M.; Johnson, L.; McEvilly, T.; More, J.; Newman, G.; Oldenburg, D.; Parker, P.; Porto, B.; Sen, M.; Torczon, V.; Vasco, D.; Woodward, N.B.

    2000-10-01

    A fundamental part of geophysics is to make inferences about the interior of the earth on the basis of data collected at or near the surface of the earth. In almost all cases these measured data are only indirectly related to the properties of the earth that are of interest, so an inverse problem must be solved in order to obtain estimates of the physical properties within the earth. In February of 1999 the U.S. Department of Energy sponsored a workshop that was intended to examine the methods currently being used to solve geophysical inverse problems and to consider what new approaches should be explored in the future. The interdisciplinary area between inverse problems in geophysics and optimization methods in mathematics was specifically targeted as one where an interchange of ideas was likely to be fruitful. Thus about half of the participants were actively involved in solving geophysical inverse problems and about half were actively involved in research on general optimization methods. This report presents some of the topics that were explored at the workshop and the conclusions that were reached. In general, the objective of a geophysical inverse problem is to find an earth model, described by a set of physical parameters, that is consistent with the observational data. It is usually assumed that the forward problem, that of calculating simulated data for an earth model, is well enough understood so that reasonably accurate synthetic data can be generated for an arbitrary model. The inverse problem is then posed as an optimization problem, where the function to be optimized is variously called the objective function, misfit function, or fitness function. The objective function is typically some measure of the difference between observational data and synthetic data calculated for a trial model. However, because of incomplete and inaccurate data, the objective function often incorporates some additional form of regularization, such as a measure of smoothness

  3. Laboratory astrophysics: Investigation of planetary and astrophysical maser emission

    NASA Astrophysics Data System (ADS)

    Bingham, R.; Speirs, D. C.; Kellett, B. J.; Vorgul, I.; McConville, S. L.; Cairns, R. A.; Cross, A. W.; Phelps, A. D. R.; Ronald, K.

    This paper describes a model for cyclotron maser emission applicable to planetary auroral radio emission, the stars UV Ceti and CU Virginus, blazar jets and astrophysical shocks. These emissions may be attributed to energetic electrons moving into convergent magnetic fields that are typically found in association with dipole like planetary magnetospheres or shocks. It is found that magnetic compression leads to the formation of a velocity distribution having a horseshoe shape as a result of conservation of the electron magnetic moment. Under certain plasma conditions where the local electron plasma frequency ω pe is much less than the cyclotron frequency ω ce the distribution is found to be unstable to maser type radiation emission. We have established a laboratory-based facility that has verified many of the details of our original theoretical description and agrees well with numerical simulations. The experiment has demonstrated that the horseshoe distribution produces cyclotron emission at a frequency just below the local electron cyclotron frequency, with polarisation close to X-mode and propagating nearly perpendicularly to the electron beam motion. We discuss recent developments in the theory and simulation of the instability including addressing radiation escape problems, and relate these to the laboratory, space, and astrophysical observations. The experiments showed strong narrow band EM emissions at frequencies just below the cold-plasma cyclotron frequency as predicted by the theory. Measurements of the conversion efficiency, mode and spectral content were in close agreement with the predictions of numerical simulations undertaken using a particle-in-cell code and also with satellite observations confirming the horseshoe maser as an important emission mechanism in geophysical/astrophysical plasmas. In each case we address how the radiation can escape the plasma without suffering strong absorption at the second harmonic layer.

  4. Laboratory astrophysics: Investigation of planetary and astrophysical maser emission

    NASA Astrophysics Data System (ADS)

    Bingham, R.; Speirs, D. C.; Kellett, B. J.; Vorgul, I.; McConville, S. L.; Cairns, R. A.; Cross, A. W.; Phelps, A. D. R.; Ronald, K.

    2013-10-01

    This paper describes a model for cyclotron maser emission applicable to planetary auroral radio emission, the stars UV Ceti and CU Virginus, blazar jets and astrophysical shocks. These emissions may be attributed to energetic electrons moving into convergent magnetic fields that are typically found in association with dipole like planetary magnetospheres or shocks. It is found that magnetic compression leads to the formation of a velocity distribution having a horseshoe shape as a result of conservation of the electron magnetic moment. Under certain plasma conditions where the local electron plasma frequency ω pe is much less than the cyclotron frequency ω ce the distribution is found to be unstable to maser type radiation emission. We have established a laboratory-based facility that has verified many of the details of our original theoretical description and agrees well with numerical simulations. The experiment has demonstrated that the horseshoe distribution produces cyclotron emission at a frequency just below the local electron cyclotron frequency, with polarisation close to X-mode and propagating nearly perpendicularly to the electron beam motion. We discuss recent developments in the theory and simulation of the instability including addressing radiation escape problems, and relate these to the laboratory, space, and astrophysical observations. The experiments showed strong narrow band EM emissions at frequencies just below the cold-plasma cyclotron frequency as predicted by the theory. Measurements of the conversion efficiency, mode and spectral content were in close agreement with the predictions of numerical simulations undertaken using a particle-in-cell code and also with satellite observations confirming the horseshoe maser as an important emission mechanism in geophysical/astrophysical plasmas. In each case we address how the radiation can escape the plasma without suffering strong absorption at the second harmonic layer.

  5. Overview of NASA Astrophysics Program Analysis Groups

    NASA Astrophysics Data System (ADS)

    Sanders, Wilton T.; Sambruna, Rita M.; Perez, Mario R.; Hudgins, Douglas M.

    2015-01-01

    NASA Astrophysics Program Analysis Groups (PAGs) are responsible for facilitating and coordinating community input into the development and execution of NASAs three astrophysics science themes: Cosmic Origins (COPAG), Exoplanet Exploration (ExoPAG), and Physics of the Cosmos (PhysPAG). The PAGs provide a community-based, interdisciplinary forum for analyses that support and inform planning and prioritization of activities within the Astrophysics Division programs. Operations and structure of the PAGs are described in their Terms of Reference (TOR), which can be found on the three science theme Program Office web pages. The Astrophysics PAGs report their input and findings to NASA through the Astrophysics Subcommittee of the NASA Advisory Council, of which all the PAG Chairs are members. In this presentation, we will provide an overview of the ongoing activities of NASAs Astrophysics PAGs in the context of the opportunities and challenges currently facing the Astrophysics Division. NASA Headquarters representatives for the COPAG, ExoPAG, and PhysPAG will all be present and available to answer questions about the programmatic role of the Astrophysics PAGs.

  6. Overview of NASA Astrophysics Program Analysis Groups

    NASA Astrophysics Data System (ADS)

    Garcia, Michael R.; Hudgins, D. M.; Sambruna, R. M.

    2014-01-01

    NASA Astrophysics Program Analysis Groups (PAGs) are responsible for facilitating and coordinating community input into the developmentand execution of NASAs three astrophysics science themes: Cosmic Origins (COPAG), Exoplanet Exploration (ExoPAG), and Physics of the Cosmos (PhysPAG). The PAGs provide a community-based, interdisciplinary forum for analyses that support and inform planning and prioritization of activities within the Astrophysics Division programs. Operations and structure of the PAGs are described in the Terms of Reference (TOR) which can be found on the three science theme Program Office web pages. The Astrophysics PAGs report their input and findings to NASA through the Astrophysics Subcommittee of the NASA Advisory Council, of which all the PAG Chairs are members. In this presentation, we will provide an overview of the ongoing activities of NASAs Astrophysics PAGs in the context of the opportunities and challenges currently facing the Astrophysics Division. NASA Headquarters representatives for the COPAG, ExoPAG, and PhysPAG will all be present and available to answer questions about the programmatic role of the Astrophysics PAGs.

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

    SciTech Connect

    He, Yudong |

    1995-07-01

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

  8. Computational Infrastructure for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Smith, M. S.; Lingerfelt, E. J.; Scott, J. P.; Nesaraja, C. D.; Hix, W. R.; Bardayan, D. W.; Blackmon, J. C.; Chae, K.; Guidry, M. W.; Hard, C. C.; Sharp, J. E.; Kozub, R. L.; Meyer, R. A.

    2004-12-01

    The Computational Infrastructure for Nuclear Astrophysics is a platform-independent, online suite of computer codes developed by the ORNL Nuclear Data Project that makes a rapid connection between laboratory nuclear physics results and astrophysical models. It enables users to evaluate cross sections, process them into thermonuclear reaction rates, and parameterize (with a few percent accuracy) these rates that vary by up to 30 orders of magnitude over the temperatures of interest. Users can then properly format these rates for input into astrophysical computer simulations, create and manipulate libraries of rates, as well as run and visualize sample post-processing nucleosynthesis calculations. For example, we have developed animated nuclide charts that show how predicted abundances (represented by a user-defined color scale) change in time. With this unique suite, users can within a very short time quantify the astrophysical impact of a newly measured or calculated cross section, or a newly created customized reaction rate library, and then document and share their results with the scientific community. The suite has a straightforward interface with a "Windows Wizard" motif whereby users progress through complicated calculations in a step-by-step fashion. Users can upload their own files for processing and save their work on our server, as well as work with files that other users wish to share. These tools are currently being used to investigate novae and X-ray bursts. The suite is available through nucastrodata.org, a website that also hyperlinks available nuclear data sets relevant for nuclear astrophysics research. New features are continually being added to this software, which is funded by the U.S. Department of Energy Low Energy Nuclear Physics and Nuclear Data Programs. ORNL is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

  9. Astrophysical processes on the Sun

    PubMed Central

    Parnell, Clare E.

    2012-01-01

    Over the past two decades, there have been a series of major solar space missions, namely Yohkoh, SOHO, TRACE, and in the past 5 years, STEREO, Hinode and SDO, studying various aspects of the Sun and providing images and spectroscopic data with amazing temporal, spatial and spectral resolution. Over the same period, the type and nature of numerical models in solar physics have been completely revolutionized as a result of widespread accessibility to parallel computers. These unprecedented advances on both observational and theoretical fronts have led to significant improvements in our understanding of many aspects of the Sun's behaviour and furthered our knowledge of plasma physics processes that govern solar and other astrophysical phenomena. In this Theme Issue, the current perspectives on the main astrophysical processes that shape our Sun are reviewed. In this Introduction, they are discussed briefly to help set the scene. PMID:22665891

  10. Nuclear and particle astrophysics

    SciTech Connect

    Glendenning, N.K.

    1990-10-31

    We discuss the physics of matter that is relevant to the structure of compact stars. This includes nuclear, neutron star matter and quark matter and phase transitions between them. Many aspects of neutron star structure and its dependance on a number of physical assumptions about nuclear matter properties and hyperon couplings are investigated. We also discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neuron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general of theory of relativity is correct at the macroscopic scale. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Indeed the prompt explosion, from which a constraint had been thought to follow, is now believed not to be mechanism by which most, if any stars, explode. In any case the nuclear equation of state is but one of a multitude on uncertain factors, and possibly one of the least important. The rapid rotation of pulsars is also discussed. It is shown that for periods below a certain limit it becomes increasingly difficult to reconcile them with neutron stars. Strange stars are possible if strange matter is the absolute ground state. We discuss such stars and their compatibility with observation. 112 refs., 37 figs., 6 tabs.

  11. Geophysical Sounding

    NASA Astrophysics Data System (ADS)

    Blake, E.

    1998-01-01

    Of the many geophysical remote-sensing techniques available today, a few are suitable for the water ice-rich, layered material expected at the north martian ice cap. Radio echo sounding has been used for several decades to determine ice thickness and internal structure. Selection of operating frequency is a tradeoff between signal attenuation (which typically increases with frequency and ice temperature) and resolution (which is proportional to wavelength). Antenna configuration and size will be additional considerations for a mission to Mars. Several configurations for ice-penetrating radar systems are discussed: these include orbiter-borne sounders, sounding antennas trailed by balloons and penetrators, and lander-borne systems. Lander-borne systems could include short-wave systems capable of resolving fine structure and layering in the upper meters beneath the lander. Spread-spectrum and deconvolution techniques can be used to increase the depth capability of a radar system. If soundings over several locations are available (e.g., with balloons, rovers, or panning short-wave systems), then it will be easier to resolve internal layering, variations in basal reflection coefficient (from which material properties may be inferred), and the geometry of nonhorizontal features. Sonic sounding has a long history in oil and gas exploration. It is, however, unlikely that large explosive charges, or even swept-frequency techniques such as Vibroseis, would be suitable for a Polar lander -- these systems are capable of penetrating several kilometers of material at frequencies of 10-200 Hz, but the energy required to generate the sound waves is large and potentially destructive. The use of audio-frequency and ultrasonic sound generated by piezoelectric crystals is discussed as a possible method to explore layering and fine features in the upper meters of the ice cap. Appropriate choice of transducer(s) will permit operation over a range of fixed or modulated frequencies

  12. Future Experiments in Astrophysics

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.

    2002-01-01

    The measurement methodologies of astrophysics experiments reflect the enormous variation of the astrophysical radiation itself. The diverse nature of the astrophysical radiation, e.g. cosmic rays, electromagnetic radiation, and neutrinos, is further complicated by the enormous span in energy, from the 1.95 Kappa relic neutrino background to cosmic rays with energy greater than 10(exp 20)eV. The measurement of gravity waves and search for dark matter constituents are also of astrophysical interest. Thus, the experimental techniques employed to determine the energy of the incident particles are strongly dependent upon the specific particles and energy range to be measured. This paper summarizes some of the calorimetric methodologies and measurements planned by future astrophysics experiments. A focus will be placed on the measurement of higher energy astrophysical radiation. Specifically, future cosmic ray, gamma ray, and neutrino experiments will be discussed.

  13. Adventures in theoretical astrophysics

    NASA Astrophysics Data System (ADS)

    Farmer, Alison Jane

    This thesis is a tour of topics in theoretical astrophysics, unified by their diversity and their pursuit of physical understanding of astrophysical phenomena. In the first chapter, we raise the possibility of the detection of white dwarfs in transit surveys for extrasolar Earths, and discuss the peculiarities of detecting these more massive objects. A population synthesis calculation of the gravitational wave background from extragalactic binary stars is then presented. In this study, we establish a firm understanding of the uncertainties in such a calculation and provide a valuable reference for planning the Laser Interferometer Space Antenna mission. The long-established problem of cosmic ray confinement to the Galaxy is addressed in another chapter. We introduce a new wave damping mechanism, due to the presence of background turbulence, that prevents the confinement of cosmic rays by the resonant streaming instability. We also investigate the spokes in Saturn's B ring, an electrodynamic mystery that is being illuminated by new data sent back from the Cassini spacecraft. In particular, we present assessments of the presence of charged dust near the rings, and the size of currents and electric fields in the ring system. We make inferences from the Cassini discovery of oxygen ions above the rings. In addition, the previous leading theory for spoke formation is demonstrated to be unphysical. In the final chapter, we explain the wayward motions of Prometheus and Pandora, two small moons of Saturn. Previously found to be chaotic as a result of mutual interactions, we account for their behavior by analogy with a parametric pendulum. We caution that this behavior may soon enter a new regime.

  14. High Energy Astrophysics Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report reviews activities performed by members of the USRA (Universities Space Research Association) contract team during the six months during the reporting period (10/95 - 3/96) and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science, Archive Research Center (HEASARC), and others.

  15. High Energy Astrophysics Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report reviews activities performed-by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, visiting the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA); X-ray Timing Experiment (XTE); X-ray Spectrometer (XRS); Astro-E; High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

  16. Neutron reactions in astrophysics

    NASA Astrophysics Data System (ADS)

    Reifarth, R.; Lederer, C.; Käppeler, F.

    2014-05-01

    The quest for the origin of matter in the Universe had been the subject of philosophical and theological debates over the history of mankind, but quantitative answers could be found only by the scientific achievements of the last century. A first important step on this way was the development of spectral analysis by Kirchhoff and Bunsen in the middle of the 19th century, which provided first insight in the chemical composition of the sun and the stars. The energy source of the stars and the related processes of nucleosynthesis, however, could be revealed only with the discoveries of nuclear physics. A final break-through came eventually with the compilation of elemental and isotopic abundances in the solar system, which reflect the various nucleosynthetic processes in detail. This review focuses on the mass region above iron, where the formation of the elements is dominated by neutron capture, mainly in the slow (s) and rapid (r) processes. Following a brief historic account and a sketch of the relevant astrophysical models, emphasis is put on the nuclear physics input, where status and perspectives of experimental approaches are presented in some detail, complemented by the indispensable role of theory.

  17. Turbulence and Magnetic Fields in Astrophysics

    NASA Astrophysics Data System (ADS)

    Matthaeus, W. H.

    2004-10-01

    The juxtaposition of ``magnetic fields'' and ``turbulence'' arises in plasma dynamics in various contexts-such as the solar corona, the magnetosphere, space physics in general, cosmic ray propagation, and laboratory plasmas of both fusion and nonfusion types. In astrophysics, the impact of turbulence has arrived relatively recently but is rapidly finding importance. The present volume is a written record of topics presented at a conference, Simulations of Magnetohydrodynamic Turbulence in Astrophysics: Recent Achievements and Perspectives, held at the Institut Henri Poincare, in Paris, in July 2001. The international audience that attended this meeting heard talks on a broad range of astrophysical, space physics, and purely theoretical subjects. A wide range of physical scenarios was discussed, with many different observational data presented. However, true to the conference banner, the emphasis was on the physics of low-frequency plasma turbulence, described by magnetohydrodyamics (MHD), and investigated using numerical simulation.

  18. Sustainable urban development and geophysics

    NASA Astrophysics Data System (ADS)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

    The new millennium has seen a fresh wave of world economic development especially in the Asian-Pacific region. This has contributed to further rapid urban expansion, creating shortages of energy and resources, degradation of the environment, and changes to climatic patterns. Large-scale, new urbanization is mostly seen in developing countries but urban sprawl is also a major social problem for developed nations. Urbanization has been accelerating at a tremendous rate. According to data collected by the United Nations [1], 50 years ago less than 30% of the world population lived in cities. Now, more than 50% are living in urban settings which occupy only about 1% of the Earth's surface. During the period from 1950 to 1995, the number of cities with a population higher than one million increased from 83 to 325. By 2025 it is estimated that more than 60% of 8.3 billion people (the projected world population [1]) will be city dwellers. Urbanization and urban sprawl can affect our living quality both positively and negatively. In recent years geophysics has found significant and new applications in highly urbanized settings. Such applications are conducive to the understanding of the changes and impacts on the physical environment and play a role in developing sustainable urban infrastructure systems. We would like to refer to this field of study as 'urban geophysics'. Urban geophysics is not simply the application of geophysical exploration in the cities. Urbanization has brought about major changes to the geophysical fields of cities, including those associated with electricity, magnetism, electromagnetism and heat. An example is the increased use of electromagnetic waves in wireless communication, transportation, office automation, and computer equipment. How such an increased intensity of electromagnetic radiation affects the behaviour of charged particles in the atmosphere, the equilibrium of ecological systems, or human health, are new research frontiers to be

  19. Herzberg Institute of Astrophysics

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Herzberg Institute of Astrophysics (HIA) is the Institute within the NATIONAL RESEARCH COUNCIL of Canada responsible for providing astronomical facilities, and developing related instrumentation and software for Canadian researchers. The Institute was established in 1975, and now operates 1.8 m and 1.2 m optical telescopes at the DOMINION ASTROPHYSICAL OBSERVATORY close to Victoria, BC, as we...

  20. Strategic Plans for the Future of Solar Physics: a community discussion of the NASA Sun-Earth Connection Program Roadmap and the NAS Decadal Survey of Astronomy and Astrophysics (Solar Astronomy section)

    NASA Astrophysics Data System (ADS)

    Schrijver, K.; Knoelker, M.

    1999-05-01

    The NASA Sun-Earth Connections Program is currently revising its Roadmap, the long-range plan for science goals, technology development, and missions between 2000 and 2040. From the interior dynamics of the Sun, to the interactions of plasma, fields, and radiation in the photosphere and solar atmosphere, to the heating and structure of the corona, to the acceleration, structure, and evolution of the solar wind, to the interactions of the heliosphere with the interstellar medium, to the processes of solar, stellar, and solar system evolution - progress in each of these domains will help us understand how the Sun impacts our home in space. The Roadmap Committee is seeking to refine and extend the SEC's vision and identify the milestone missions for the future. During this session, an outline of the current draft Roadmap will be presented, and further community involvement will be solicited to ensure the strongest possible concensus on the revised Roadmap. The National Academy of Sciences' Space Science Board has appointed a committee to perform a Decadal Survey of Astronomy and Astrophysics, which is surveying the field of space- and ground-based astronomy and astrophysics, recommending priorities for the most important new initiatives of the decade 2000-2010. The prioritization delivered by the earlier Decadal Surveys has played an important role in guiding the funding agencies in setting their priorities for astronomy and astrophysics. Therefore it will be of crucial importance for solar physics to contribute a strong case for its own set of future projects to be incorpoprated into the survey. The solar physics of the next decade will be characterized by its increasing societal relevance in the context of the National Space Weather Program and related issues, as well as its classical importance as a ``base" for many astrophysical questions. The presentation and subsequent discussion at the Chicago meeting is intended to solicit further community input, to achieve

  1. The Blackholic energy: long and short Gamma-Ray Bursts (New perspectives in physics and astrophysics from the theoretical understanding of Gamma-Ray Bursts, II)

    NASA Astrophysics Data System (ADS)

    Ruffini, Remo; Bernardini, Maria Grazia; Bianco, Carlo Luciano; Chardonnet, Pascal; Fraschetti, Federico; Gurzadyan, Vahe; Vitagliano, Luca; Xue, She-Sheng

    2005-08-01

    hypothesis is considered to relate this X-ray source to a neutron star, newly born in the Supernova. This hypothesis should be submitted to further theoretical and observational investigation. Some theoretical developments to clarify the astrophysical origin of this new scenario are outlined. We turn then to the theoretical developments in the short GRBs: we first report some progress in the understanding the dynamical phase of collapse, the mass-energy formula and the extraction of blackholic energy which have been motivated by the analysis of the short GRBs. In this context progress has also been accomplished on establishing an absolute lower limit to the irreducible mass of the black hole as well as on some critical considerations about the relations of general relativity and the second law of thermodynamics. We recall how this last issue has been one of the most debated in theoretical physics in the past thirty years due to the work of Bekenstein and Hawking. Following these conceptual progresses we analyze the vacuum polarization process around an overcritical collapsing shell. We evidence the existence of a separatrix and a dyadosphere trapping surface in the dynamics of the electron-positron plasma generated during the process of gravitational collapse. We then analyze, using recent progress in the solution of the Vlasov-Boltzmann-Maxwell system, the oscillation regime in the created electron-positron plasma and their rapid convergence to a thermalized spectrum. We conclude by making precise predictions for the spectra, the energy fluxes and characteristic time-scales of the radiation for short-bursts. If the precise luminosity variation and spectral hardening of the radiation we have predicted will be confirmed by observations of short-bursts, these systems will play a major role as standard candles in cosmology. These considerations will also be relevant for the analysis of the long-bursts when the baryonic matter contribution will be taken into account.

  2. Astrophysical, Geochemical, Geophysical and Biological Limits on Planet Habitability

    NASA Astrophysics Data System (ADS)

    Lineweaver, C.

    2014-03-01

    For life forms like us, the most important feature of the Earth is its habitability. Understanding habitability and using that knowledge to locate the nearest habitable planet may be crucial for our survival as a species. Over the past decade, expectations that the universe could be filled with habitable planets have been bolstered by the increasingly large overlap between terrestrial environments known to harbor life and the variety of environments on newly detected rocky exoplanets. The inhabited and uninhabited regions on Earth tell us that temperature and the presence of water are the main constraints that can be used in a habitability classification scheme for rocky planets. Our compilation and review of recent exoplanet detections suggests that the fraction of stars with planets is ~ 100%, and that the fraction with rocky planets may be comparably large. We review extensions to the circumstellar habitable zone including an abiogenesis habitable zone and the galactic habitable zone.

  3. GEOPHYSICS, ASTRONOMY AND ASTROPHYSICS: Refractivity estimation from radar sea clutter

    NASA Astrophysics Data System (ADS)

    Huang, Si-Xun; Zhao, Xiao-Feng; Sheng, Zheng

    2009-11-01

    This paper addresses the problem of estimating lower atmospheric refractivity under the nonstandard propagation conditions frequently encountered in low altitude maritime radar applications. The vertical structure of the refractive environment is modeled by using a five-parameter model, and the horizontal structure is modeled as range-independent. The electromagnetic propagation in the troposphere is simulated by using a split-step fast Fourier transform based on parabolic approximation to the wave equation. A global search marked as a modified genetic algorithm (MGA) for the 5 environmental parameters is performed by using a genetic algorithm (GA) integrated with a simulated annealing technique. The retrieved results from simulated runs demonstrate the ability of this method to make atmospheric refractivity estimations. A comparison with the classical GA and the Bayesian Markov Chain Monte Carlo (Bayesian-MCMC) technique shows that the MGA can not only shorten the inverse time but also improve the inverse precision. For real data cases, the inversion values do not match the reference data very well. The inverted profile, however, can be used to synoptically describe the real refractive structure.

  4. The History of Astrophysics in Antarctica

    NASA Astrophysics Data System (ADS)

    Indermuehle, Balthasar T.; Burton, Michael G.; Maddison, Sarah T.

    We examine the historical development of astrophysical science in Antarctica from the early 20th century until today. We find three temporally overlapping eras, each having a rather distinct beginning. These are the astrogeological era of meteorite discovery, the high energy era of particle detectors, and the photon astronomy era of microwave, submillimetre, and infrared telescopes, sidelined by a few niche experiments at optical wavelengths. The favourable atmospheric and geophysical conditions are briefly examined, followed by an account of the major experiments and a summary of their results.

  5. Advances in instrumentation for nuclear astrophysics

    SciTech Connect

    Pain, S. D.

    2014-04-15

    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. Handbook of Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysical methods continue to show great promise for use in agriculture. The term “agricultural geophysics” denotes a subdiscipline of geophysics that is focused only on agricultural applications. The Handbook of Agricultural Geophysics was compiled to include a comprehensive overview of the geoph...

  7. Physics through the 1990s: Plasmas and fluids

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The volume contains recommendations for programs in, and government support of, plasma and fluid physics. Four broad areas are covered: the physics of fluids, general plasma physics, fusion, and space and astrophysical plasmas. In the first section, the accomplishments of fluid physics and a detailed review of its sub-fields, such as combustion, non-Newtonian fluids, turbulence, aerodynamics, and geophysical fluid dynamics, are described. The general plasma physics section deals with the wide scope of the theoretical concepts involved in plasma research, and with the machines; intense beam systems, collective and laser-driven accelerators, and the associated diagnostics. The section on the fusion plasma research program examines confinement and heating systems, such as Tokamaks, magnetic mirrors, and inertial-confinement systems, and several others. Finally, theory and experiment in space and astrophysical plasma research is detailed, ranging from the laboratory to the solar system and beyond. A glossary is included.

  8. High Energy Astrophysics Mission

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.; Ormes, Jonathan F. (Technical Monitor)

    2000-01-01

    The nature of gravity and its relationship to the other three forces and to quantum theory is one of the major challenges facing us as we begin the new century. In order to make progress we must challenge the current theories by observing the effects of gravity under the most extreme conditions possible. Black holes represent one extreme, where the laws of physics as we understand them break down. The Universe as whole is another extreme, where its evolution and fate is dominated by the gravitational influence of dark matter and the nature of the Cosmological constant. The early universe represents a third extreme, where it is thought that gravity may somehow be unified with the other forces. NASA's "Cosmic Journeys" program is part of a NASA/NSF/DoE tri-agency initiative designed to observe the extremes of gravity throughout the universe. This program will probe the nature of black holes, ultimately obtaining a direct image of the event horizon. It will investigate the large scale structure of the Universe to constrain the location and nature of dark matter and the nature of the cosmological constant. Finally it will search for and study the highest energy processes, that approach those found in the early universe. I will outline the High Energy Astrophysics part of this program.

  9. Introduction to Stellar Astrophysics

    NASA Astrophysics Data System (ADS)

    Böhm-Vitense, Erika

    1992-01-01

    This book is the final one in a series of three texts which together provide a modern, complete and authoritative account of our present knowledge of the stars. It discusses the internal structure and the evolution of stars, and is completely self-contained. There is an emphasis on the basic physics governing stellar structure and the basic ideas on which our understanding of stellar structure is based. The book also provides a comprehensive discussion of stellar evolution. Careful comparison is made between theory and observation, and the author has thus provided a lucid and balanced introductory text for the student. As for volumes 1 and 2, volume 3 is self-contained and can be used as an independent textbook. The author has not only taught but has also published many original papers in this subject. Her clear and readable style should make this text a first choice for undergraduate and beginning graduate students taking courses in astronomy and particularly in stellar astrophysics.

  10. Astrophysical smooth particle hydrodynamics

    NASA Astrophysics Data System (ADS)

    Rosswog, Stephan

    2009-04-01

    The paper presents a detailed review of the smooth particle hydrodynamics (SPH) method with particular focus on its astrophysical applications. We start by introducing the basic ideas and concepts and thereby outline all ingredients that are necessary for a practical implementation of the method in a working SPH code. Much of SPH's success relies on its excellent conservation properties and therefore the numerical conservation of physical invariants receives much attention throughout this review. The self-consistent derivation of the SPH equations from the Lagrangian of an ideal fluid is the common theme of the remainder of the text. We derive a modern, Newtonian SPH formulation from the Lagrangian of an ideal fluid. It accounts for changes of the local resolution lengths which result in corrective, so-called "grad-h-terms". We extend this strategy to special relativity for which we derive the corresponding grad-h equation set. The variational approach is further applied to a general-relativistic fluid evolving in a fixed, curved background space-time. Particular care is taken to explicitly derive all relevant equations in a coherent way.

  11. Particle Astrophysics Using Balloons

    NASA Astrophysics Data System (ADS)

    Seo, E. S.

    Cosmic rays, energetic particles coming from outer space, bring us information about the physical processes that accelerate particles to relativistic energies, about the effects of those particles in driving dynamical processes in our Galaxy, and about the distribution of matter and fields in interstellar space. Cosmic rays were discovered in the early twentieth century using a balloon-borne electroscope. Balloons are currently being used for answering fundamental questions about the cosmos: (1) Is the Universe symmetric, and if so where is the antimatter? (2) What is the dark matter? (3) How do cosmic rays get their enormous energies? (4) Can the entire energy spectrum of cosmic rays result from a single acceleration mechanism? (5) Are supernovae really the sources of cosmic rays? (6) What is the history of cosmic rays in the Galaxy? (7) What is the origin of the "knee" in the cosmic ray energy spectrum? etc. The status of results from past balloon-borne measurements and expected results from ongoing and planned future balloon-borne particle astrophysics experiments will be reviewed.

  12. Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Busse, F. H.

    In the past 8 years, since Pedlosky's book was first published, it has found a well established place in the literature of dynamical meteorology and physical oceanography. Geophysicists less familiar with these fields may need to be reminded that the subject of geophysical fluid dynamics, in the narrow definition used in the title of the book, refers to the theory of the large-scale motions of the atmosphere and the oceans. Topics such as thermal convection in the atmosphere or in Earth's mantle and core are not treated in this book, and the reader will search in vain for a discussion of atmospheric or oceanic tides. The theory of quasi-geostrophic flow is described comprehensively, however, and its major applications to problems of atmospheric and oceanic circulations are considered in detail.

  13. Geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Wells, R. A.

    1979-01-01

    A physical model of Mars is presented on the basis of light-scattering observations of the Martian atmosphere and surface and interior data obtained from observations of the geopotential field. A general description of the atmosphere is presented, with attention given to the circulation and the various cloud types, and data and questions on the blue haze-clearing effect and the seasonal darkening wave are summarized and the Mie scattering model developed to explain these observations is presented. The appearance of the planet from earth and spacecraft through Mariner 9 is considered, and attention is given to the preparation of topographical contour maps, the canal problem and large-scale lineaments observed from Mariner 9, the gravity field and shape of the planet and the application of Runcorn's geoid/convection theory to Mars. Finally, a summary of Viking results is presented and their application to the understanding of Martian geophysics is discussed.

  14. Serious games for Geophysics

    NASA Astrophysics Data System (ADS)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

    Childhood stage is indispensable in the education of human beings and especially critical to arise scientific interest in children. We discuss the participatory design of a didactic videogame, i.e. a "serious" game to teach geophysics and Earth sciences to high and low-school students. Geophysics is the application of the laws and techniques of physics to uncover knowledge about the earth's dynamic processes and subsurface structure. It explores phenomena such as earthquakes, volcanoes, tsunamis to improve our understanding of the earth's physical processes and our ability to predict reoccurrences. Effective mitigation of risks from catastrophic geologic hazards requires knowledge and understanding of local geology and geologic processes. Scientific outreach can be defined as discourse activity, whose main objective is to communicate some knowledge previously produced in scientific contexts to a non-expert massive audience. One of the difficulties science educators need to overcome is to explain specific concepts from a given discipline in a language simple and understandable for their audience. Digital games today play a large role in young people's lives. Games are directly connected to the life of today's adolescents. Therefore, digital games should be included and broached as a subject in the classroom. The ardor and enthusiasm that digital games evoke in teenagers has indeed brought many researchers, school leaders and teachers to the question "how video games" can be used to engage young people and support their learning inside the classroom. Additionally, studies have shown that digital games can enhance various skills such as the ability to concentrate, stamina, tactical aptness, anticipatory thinking, orientation in virtual spaces, and deductive reasoning. Thus, videogames become an effective didactic mechanism and should have a place in the classroom. The project aims to explore the potentials of entertainment technologies in educational processes

  15. Exotic nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2012-07-01

    Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei's discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of

  16. Transient Astrophysics Observatory (TAO)

    NASA Astrophysics Data System (ADS)

    Racusin, J. L.; TAO Team

    2016-10-01

    The Transient Astrophysics Observatory (TAO) is a NASA MidEx mission concept (formerly known as Lobster) designed to provide simultaneous wide-field gamma-ray, X-ray, and near-infrared observations of the sky.

  17. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  18. Geophysical fields of a megalopolis

    NASA Astrophysics Data System (ADS)

    Spivak, A. A.; Loktev, D. N.; Rybnov, Yu. S.; Soloviev, S. P.; Kharlamov, V. A.

    2016-12-01

    A description of the Center of Geophysical Monitoring for Systematic Investigation of Negative Consequences for the Human Environment and Infrastructure of the City of Moscow Resulting from Natural and Technogenic Factors, which is part of the Institute of Geosphere Dynamics of the Russian Academy of Sciences (IGD RAS), is presented. The results of synchronous observations of the seismic vibrations, electric and acoustic fields, and atmospheric meteoparameters performed at the Center and in the Mikhnevo Geophysical observatory of IGD RAS situated outside of the zone of the Moscow influence are examined. It is shown that the megalopolis influence consists of an increase in the amplitudes of the physical fields, a change in their spectral composition, and the violation of natural periodicities. A technogenic component that has a considerable impact on the natural physical processes in the surface atmosphere is an important factor that characterizes a megalopolis.

  19. Dominion Radio Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Dominion Radio Astrophysical Observatory began operating in 1959, and joined the NATIONAL RESEARCH COUNCIL in 1970. It became part of the Herzberg Institute of Astrophysics in 1975. The site near Penticton, BC has a 26 m radio telescope, a seven-antenna synthesis telescope on a 600 m baseline and two telescopes dedicated to monitoring the solar radio flux at 10.7 cm. This part of the Institu...

  20. Ion irradiation of astrophysical ices

    NASA Astrophysics Data System (ADS)

    Palumbo, M. E.; Baratta, G. A.; Fulvio, D.; Garozzo, M.; Gomis, O.; Leto, G.; Spinella, F.; Strazzulla, G.

    2008-02-01

    Ices, silicates and carbonaceous materials have been detected in several astrophysical environments such as interstellar molecular clouds, comets, and planetary surfaces. These solids are continuously exposed to ion irradiation and UV photolysis. Our knowledge on the properties of solids and molecules and on the modification induced by fast ions (keV-MeV) and UV photons is mainly based on laboratory experiments and on the comparison of experimental results with observations. Here we will give a few examples of the role of laboratory experiments to our understanding of the physical and chemical properties of ices in space.

  1. Astrophysics on the lab bench

    NASA Astrophysics Data System (ADS)

    Hughes, Stephen W.

    2010-05-01

    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 type II supernova explosion. In another experiment, students roll marbles up and down a double ramp in an attempt to get a marble to enter a tube halfway up the slope, which illustrates quantum tunnelling in stellar cores. The experiments are reasonably low cost to either purchase or manufacture.

  2. High-energy spectroscopic astrophysics

    NASA Astrophysics Data System (ADS)

    Güdel, Manuel; Walter, Roland

    After three decades of intense research in X-ray and gamma-ray astronomy, the time was ripe to summarize basic knowledge on X-ray and gamma-ray spectroscopy for interested students and researchers ready to become involved in new high-energy missions. This volume exposes both the scientific basics and modern methods of high-energy spectroscopic astrophysics. The emphasis is on physical principles and observing methods rather than a discussion of particular classes of high-energy objects, but many examples and new results are included in the three chapters as well.

  3. Astrophysics teaching at Assam University, Silchar

    NASA Astrophysics Data System (ADS)

    Das, Himadri Sekhar

    The Department of Physics is established in 1996 and since, then, thirteen batches of students have completed their Master’s programmes in the subject. The Department introduced in the year 2001 Astrophysics as one special paper in PG level (in the second year). The syllabus of Astrophysics is designed to include courses from observational Astronomy to Theoretical Astrophysics and Cosmology. There are two theory papers (in third and fourth semesters), one practical paper (in third semester) and one project or dissertation paper (in fourth semester), each one carries 100 marks. The major instruments available in the department for carrying out the experimental work are Meade-16 inch telescope, Celestron-8 inch inches Telescope, Meade refracting telescopes (4 inches, 2 number), SSP-5, SSP-3 photometer, Sivo Fibre-fed Spectrometer, CCD (Meade 416 XT, ST-6), Goniometer, Limb darkening apparatus etc. The practical paper includes study of the variation of sunspots; measurement of the parallax of distant objects, on moon and on planets like Jupiter and Saturn, measurement of the magnitude of different stars, study of the light scattering properties of rough surfaces, analysis of the image by image processing software (IRAF) etc. The project papers are based on research oriented topics which covers latest trends in Astrophysics including solar system studies, Interstellar medium and star formation studies and some problems in gravito-optics. There are altogether 6 scholars who have been awarded PhD and 10 are registered for PhD in Astrophysics. Besides these, 8 scholars have been awarded M. Phil. in Astrophysics. The broad research area of Astrophysics includes light scattering properties of cosmic dust, star formation, gravito optics, polarization study of comets etc. The Astrophysics group is currently doing research in different fields and have very good publications in several peer reviewed journals of international status.

  4. Neutrino astrophysics with Hyper-Kamiokande

    NASA Astrophysics Data System (ADS)

    Yano, Takatomi; Hyper-Kamiokande proto Collaboration

    2016-05-01

    Hyper-Kamiokande (Hyper-K) is a proposed next generation underground large water Cherenkov detector. The detector consists of 1 Mt pure water tank with surrounding 99,000 newly developed photo sensors, providing fiducial volume of 0.56 Mt. The energies, positions and directions of charged particles produced by neutrino interactions are detected using its Cherenkov light in water. Our detector will be located at deep underground to reduce the cosmic muon flux and its spallation products, which is a dominant background at the low energy analysis. Hyper-K will play a considerable role in the next neutrino physics frontier, even in the neutrino astrophysics. The detection with large statistics of astrophysical neutrons, i.e., solar neutrino, supernova burst neutrino and supernova relic neutrino, will be remarkable information for both of particle physics and astrophysics.

  5. Transfer reactions in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bardayan, D. W.

    2016-08-01

    To a high degree many aspects of the large-scale behavior of objects in the Universe are governed by the underlying nuclear physics. In fact the shell structure of nuclear physics is directly imprinted into the chemical abundances of the elements. The tranquility of the night sky is a direct result of the relatively slow rate of nuclear reactions that control and determines a star’s fate. Understanding the nuclear structure and reaction rates between nuclei is vital to understanding our Universe. Nuclear-transfer reactions make accessible a wealth of knowledge from which we can extract much of the required nuclear physics information. A review of transfer reactions for nuclear astrophysics is presented with an emphasis on the experimental challenges and opportunities for future development.

  6. Sessions on history of space and geophysics spark interest

    NASA Astrophysics Data System (ADS)

    Schröder, Wilfried

    Three sessions at international conferences were held in 1997 to discuss the history of space and geophysics and its different disciplines. The first session was held during the Assembly of the German Geophysical Society in March in Potsdam, Germany. Topics included the theory of relativity and gravitation in geophysics; work by Albert Abraham Michelson, Leon Foucault, and Ernst Mach; work by Hermann von Helmholtz; and the physical application and geophysical evidence of Werner Heisenberg's research. Also included were discussions relevant to the history of geophysics, aeronomy, meteor astronomy, and geodetical research, including developments in instrumentation during the last few decades.

  7. The Geophysical Fluid Flow Cell Experiment

    NASA Technical Reports Server (NTRS)

    Hart, J. E.; Ohlsen, D.; Kittleman, S.; Borhani, N.; Leslie, F.; Miller, T.

    1999-01-01

    The Geophysical Fluid Flow Cell (GFFC) experiment performed visualizations of thermal convection in a rotating differentially heated spherical shell of fluid. In these experiments dielectric polarization forces are used to generate a radially directed buoyancy force. This enables the laboratory simulation of a number of geophysically and astrophysically important situations in which sphericity and rotation both impose strong constraints on global scale fluid motions. During USML-2 a large set of experiments with spherically symmetric heating were carried out. These enabled the determination of critical points for the transition to various forms of nonaxisymmetric convection and, for highly turbulent flows, the transition latitudes separating the different modes of motion. This paper presents a first analysis of these experiments as well as data on the general performance of the instrument during the USML-2 flight.

  8. Fiber optic geophysical sensors

    DOEpatents

    Homuth, Emil F.

    1991-01-01

    A fiber optic geophysical sensor in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects.

  9. Nuclear interactions in high energy heavy ions and applications in astrophysics. [Dept. of Physics and Astronomy, Louisiana State Univ. , Baton Rouge

    SciTech Connect

    Wefel, J.P.; Guzik, T.G.

    1993-01-11

    The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. [sup 4]He, [sup 16]O, [sup 20]Ne, [sup 28]Si, [sup 56]Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy [sup 16]O,[sup 28]Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs.

  10. Transition regions in solar system and astrophysical plasmas

    NASA Technical Reports Server (NTRS)

    Eastman, Timothy E.

    1990-01-01

    A brief review is presented of basic particle and field characteristics of plasmas observed within the solar system, especially near transition regions, and their parameter ranges are compared with those inferred for stellar winds and the interstellar medium. Parameter ranges for solar system and astrophysical plasmas are found to have considerable overlap. In addition, astrophysics provides unique, global perspectives of large-scale systems, whereas solar-system space physics provides for direct quantitative testing of physical processes. Astrophysics and solar-system space physics studies thus have complementary and synergistic roles.

  11. Three dimensional reconnection in astrophysical plasmas

    NASA Technical Reports Server (NTRS)

    Spicer, D. S.

    1990-01-01

    Theoretical issues related to three-dimensional reconnection and its application to the space and astrophysical environment are reviewed. Consideration is given to the meaning of reconnection in three dimensions, the way in which periodic and nonperiodic magnetic topologies alter the physics of reconnections, and the effects of chaotic magnetic fields on the reconnection process.

  12. Astrophysical and Geophysical Flows as Dynamical Systems. 1998 Summer Study Program in Geophysical Fluid Dynamics

    DTIC Science & Technology

    1999-01-01

    Models Really Work? Friday, August 14 2:00 pm Vachtang Poutkaradze, University of Chicago - Selective Withdrawal in Oil/ Water Systems Week of August 17...and the two new fixed points were stable. This situation is called a supercritical pitchfork bifurcation. When the new equilibria are unstable, they...a supercritical Hopf bifurcation, the growing oscillations saturate on a nearby limit cycle. But for subcritical Hopf bifurcations, an unstable limit

  13. Astrophysical and cosmological constraints to neutrino properties

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Schramm, David N.; Turner, Michael S.

    1989-01-01

    The astrophysical and cosmological constraints on neutrino properties (masses, lifetimes, numbers of flavors, etc.) are reviewed. The freeze out of neutrinos in the early Universe are discussed and then the cosmological limits on masses for stable neutrinos are derived. The freeze out argument coupled with observational limits is then used to constrain decaying neutrinos as well. The limits to neutrino properties which follow from SN1987A are then reviewed. The constraint from the big bang nucleosynthesis on the number of neutrino flavors is also considered. Astrophysical constraints on neutrino-mixing as well as future observations of relevance to neutrino physics are briefly discussed.

  14. EDITORIAL: The interface between geophysics and engineering

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Journal of Geophysics and Engineering (JGE) aims to publicize and promote research and developments in geophysics and in related areas of engineering. As stated in the journal scope, JGE is positioned to bridge the gap between earth physics and geo-engineering, where it reflects a growing trend in both industry and academia. JGE covers those aspects of engineering that bear closely on geophysics or on the targets and problems that geophysics addresses. Typically this will be engineering focused on the subsurface, particularly petroleum engineering, rock mechanics, geophysical software engineering, drilling technology, remote sensing, instrumentation and sensor design. There is a trend, visible throughout academia, for rapid expansion in cross-disciplinary, multi-disciplinary and inter-disciplinary working. Many of the most important and exciting problems and advances are being made at the boundaries between traditional subject areas and, increasingly, techniques from one discipline are finding applications in others. There is a corresponding increasing requirement for researchers to be aware of developments in adjacent areas and for papers published in one area to be readily accessible, both in terms of location and language, to those in others. One such area that is expanding rapidly is that at the interface between geophysics and engineering. There are three principal developments. Geophysics, and especially applied geophysics, is increasingly constrained by the limits of technology, particularly computing technology. Consequently, major advances in geophysics are often predicated upon major developments in engineering and many research geophysicists are working in multi-disciplinary teams with engineers. Engineering problems relevant to the sub-surface are increasingly looking to advances in geophysics to provide part of the solution. Engineering systems, for example, for tunnel boring or petroleum reservoir management, are using high-resolution geophysical

  15. Environmental and Engineering Geophysics

    NASA Astrophysics Data System (ADS)

    Sharma, Prem V.

    1997-12-01

    Geophysical imaging methods provide solutions to a wide variety of environmental and engineering problems: protection of soil and groundwater from contamination; disposal of chemical and nuclear waste; geotechnical site testing; landslide and ground subsidence hazard detection; location of archaeological artifacts. This book comprehensively describes the theory, data acquisition and interpretation of all of the principal techniques of geophysical surveying: gravity, magnetic, seismic, self-potential, resistivity, induced polarization, electromagnetic, ground-probing radar, radioactivity, geothermal, and geophysical borehole logging. Each chapter is supported by a large number of richly illustrated case histories. This book will prove to be a valuable textbook for senior undergraduates and postgraduates in environmental and applied geophysics, a supplementary course book for students of geology, engineering geophysics, civil and mining engineering, and a reference work for professional earth scientists, engineers and town planners.

  16. The Astrophysical Multimessenger Observatory Network (AMON)

    NASA Technical Reports Server (NTRS)

    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; Barthelmy, S. D.; Coutu, S.; DeYoung, T.; Falcone, A. D.; Gao, Shan; Hashemi, B.; Homeier, A.; Marka, S.; Owen, B. J.; Taboada, I.

    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.

  17. The Astrophysics Science Division Annual Report 2008

    NASA Technical Reports Server (NTRS)

    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.

  18. SciDAC Computational Astrophysics Consortium

    SciTech Connect

    Burrows, Adam

    2008-06-18

    Supernova explosions are the central events in nuclear astrophysics. The core-collapse variety is a major source for the universe's heavy elements. The neutron stars, pulsars, and stellar-mass black holes of high-energy astrophysics are their products. Given their prodigious explosion energies, they are the major agencies of change in the interstellar medium, driving star formation and the evolution of galaxies. Their gas remnants are the birthplaces of the cosmic rays. Such is their brightness that they can be used as standard candles to measure the size and geometry of the universe. Recently, there is evidence that gamma-ray bursts (GRBs) originate in a small fraction of core collapses, thereby connecting two of the most energetic phenomena in the universe. However, the mechanism by which core-collapse supernovae explode has not yet been unambiguously determined. Arguably, this is one of the great unsolved problems in modern astrophysics and its investigation draws on nuclear physics, particle physics, radiative transfer, kinetic theory, gravitational physics, thermodynamics, and the numerical arts. Hence, supernovae are unrivaled astrophysical laboratories. It is the quest for the mechanism and new insights our team has recently had that motivate this proposal.

  19. Introduction to High-Energy Astrophysics

    NASA Astrophysics Data System (ADS)

    Rosswog, Stephan; Bruggen, Marcus

    2003-04-01

    High-energy astrophysics covers cosmic phenomena that occur under the most extreme physical conditions. It explores the most violent events in the Universe: the explosion of stars, matter falling into black holes, and gamma-ray bursts - the most luminous explosions since the Big Bang. Driven by a wealth of new observations, the last decade has seen a large leap forward in our understanding of these phenomena. Exploring modern topics of high-energy astrophysics, such as supernovae, neutron stars, compact binary systems, gamma-ray bursts, and active galactic nuclei, this textbook is ideal for undergraduate students in high-energy astrophysics. It is a self-supporting, timely overview of this exciting field of research. Assuming a familiarity with basic physics, it introduces all other concepts, such as gas dynamics or radiation processes, in an instructive way. An extended appendix gives an overview of some of the most important high-energy astrophysics instruments, and each chapter ends with exercises.• New, up-to-date, introductory textbook providing a broad overview of high-energy phenomena and the many advances in our knowledge gained over the last decade • Written especially for undergraduate teaching use, it introduces the necessary physics and includes many exercises • This book fills a valuable niche at the advanced undergraduate level, providing professors with a new modern introduction to the subject

  20. SAGE (Summer of Applied Geophysical Experience): Learning Geophysics by Doing Geophysics

    NASA Astrophysics Data System (ADS)

    Jiracek, G. R.; Baldridge, W. S.; Biehler, S.; Braile, L. W.; Ferguson, J. F.; Gilpin, B. E.; Pellerin, L.

    2005-12-01

    geophysics, geology, engineering, physics, and mathematics. SAGE is sponsored by the Los Alamos National Laboratory Branch of the University of California's Institute of Geophysics and Planetary Physics. More information is available on the SAGE web site at http://www.sage.lanl.gov/.

  1. Geophysical Institute biennial report 1995--1996

    SciTech Connect

    1998-06-01

    The mission of the Geophysical Institute is to understand the basic physical processes governing Earth, especially as they occur in, or are relevant to the Arctic; to train graduate and undergraduate students to play leading roles in tomorrow`s society; to solve applied geophysical problems and develop resource-oriented technology of importance to the state and the nation; and to satisfy the intellectual and technological needs of fellow Alaskans through public service. The variety of subjects studied by the faculty, research staff members, and graduate students at the Geophysical Institute include auroral physics and chemistry, arctic haze, ice fog, atmospheric dynamics, ozone, Alaska weather patterns, regional meteorology and climatology, global climate change, cloud physics and radiation, permafrost, glaciers, sea ice, remote sensing, geothermal energy, tectonics, volcanoes and earthquakes. Summaries are presented of the projects undertaken by the Institute in these fields.

  2. Geophysics in INSPIRE

    NASA Astrophysics Data System (ADS)

    Sőrés, László

    2013-04-01

    INSPIRE is a European directive to harmonize spatial data in Europe. Its' aim is to establish a transparent, multidisciplinary network of environmental information by using international standards and OGC web services. Spatial data themes defined in the annex of the directive cover 34 domains that are closely bundled to environment and spatial information. According to the INSPIRE roadmap all data providers must setup discovery, viewing and download services and restructure data stores to provide spatial data as defined by the underlying specifications by 2014 December 1. More than 3000 institutions are going to be involved in the progress. During the data specification process geophysics as an inevitable source of geo information was introduced to Annex II Geology. Within the Geology theme Geophysics is divided into core and extended model. The core model contains specifications for legally binding data provisioning and is going to be part of the Implementation Rules of the INSPIRE directives. To minimize the work load of obligatory data transformations the scope of the core model is very limited and simple. It covers the most essential geophysical feature types that are relevant in economic and environmental context. To fully support the use cases identified by the stake holders the extended model was developed. It contains a wide range of spatial object types for geophysical measurements, processed and interpreted results, and wrapper classes to help data providers in using the Observation and Measurements (O&M) standard for geophysical data exchange. Instead of introducing the traditional concept of "geophysical methods" at a high structural level the data model classifies measurements and geophysical models based on their spatial characteristics. Measurements are classified as geophysical station (point), geophysical profile (curve) and geophysical swath (surface). Generic classes for processing results and interpretation models are curve model (1D), surface

  3. NASA's Astrophysics Program

    NASA Astrophysics Data System (ADS)

    Hertz, Paul L.

    2013-04-01

    The environment in which NASA and other Government agencies are operating is constantly changing. It is significantly different from the environment assumed by the recent 2010 Decadal Survey. NASA has described its plans for responding to the Decadal Survey in its 2012 Astrophysics Implementation Plan (http://science.nasa.gov/astrophysics/documents/). The NASA Astrophysics Division plans to: Enable the science and priorities identified by the Decadal Survey with new activities as well as through ongoing missions, including large missions, medium missions, and Explorers; Invest in the Astrophysics Research Program for developing the science cases and technologies of new missions and for maximizing the scientific return from operating missions; Engage in effective international and interagency partnerships that leverage NASA resources and extend the reach of our science results; Conduct studies of WFIRST and candidate probes that derive from the activities prioritized in the Decadal Survey and are responsive to the Decadal Survey science questions; Be prepared to begin a strategic mission, subject to the availability of funds, which follows from the Decadal Survey and is launched after the James Webb Space Telescope.

  4. Surprises in astrophysical gasdynamics.

    PubMed

    Balbus, Steven A; Potter, William J

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  5. The Astrophysics Data System

    NASA Astrophysics Data System (ADS)

    Eichhorn, Guenther; Accomazzi, Alberto; Kurtz, Michael J.; Grant, Carolyn S.

    The NASA Astrophysics Data System has been very successful in providing the researcher and librarian the capability to effectively search the astronomical and space science literature from their desktop. It currently provides access to four searchable databases of scientific bibliographic references and a large archive of full-text documents which includes all the major astronomical journals.

  6. Gamma-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W. (Editor); Trombka, J. I. (Editor)

    1973-01-01

    Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

  7. The NASA Astrophysics Program

    NASA Technical Reports Server (NTRS)

    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.

  8. Surprises in astrophysical gasdynamics

    NASA Astrophysics Data System (ADS)

    Balbus, Steven A.; Potter, William J.

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one’s a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  9. Stellar Astrophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Thompson, Michael J.; Christensen-Dalsgaard, Jørgen

    2008-02-01

    Preface; 1. A selective overview Jørgen Christensen-Dalsgaard and Michael J. Thompson; Part I. Stellar Convection and Oscillations: 2. On the diversity of stellar pulsations Wojciech A. Dziembowski; 3. Acoustic radiation and mode excitation by turbulent convection Günter Houdek; 4. Understanding roAp stars Margarida S. Cunha; 5. Waves in the magnetised solar atmosphere Colin S. Rosenthal; Part II. Stellar Rotation and Magnetic Fields: 6. Stellar rotation: a historical survey Leon Mestel; 7. The oscillations of rapidly rotating stars Michel Rieutord; 8. Solar tachocline dynamics: eddy viscosity, anti-friction, or something in between? Michael E. McIntyre; 9. Dynamics of the solar tachocline Pascale Garaud; 10. Dynamo processes: the interaction of turbulence and magnetic fields Michael Proctor; 11. Dynamos in planets Chris Jones; Part III. Physics and Structure of Stellar Interiors: 12. Solar constraints on the equation of state Werner Däppen; 13. 3He transport and the solar neutrino problem Chris Jordinson; 14. Mixing in stellar radiation zones Jean-Paul Zahn; 15. Element settling and rotation-induced mixing in slowly rotating stars Sylvie Vauclair; Part IV. Helio- and Asteroseismology: 16. Solar structure and the neutrino problem Hiromoto Shibahashi; 17. Helioseismic data analysis Jesper Schou; 18. Seismology of solar rotation Takashi Sekii; 19. Telechronohelioseismology Alexander Kosovichev; Part V. Large-Scale Numerical Experiments: 20. Bridges between helioseismology and models of convection zone dynamics Juri Toomre; 21. Numerical simulations of the solar convection zone Julian R. Elliott; 22. Modelling solar and stellar magnetoconvection Nigel Weiss; 23. Nonlinear magnetoconvection in the presence of a strong oblique field Keith Julien, Edgar Knobloch and Steven M. Tobias; 24. Simulations of astrophysical fluids Marcus Brüggen; Part VI. Dynamics: 25. A magic electromagnetic field Donald Lynden-Bell; 26. Continuum equations for stellar dynamics Edward A

  10. Stellar Astrophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Thompson, Michael J.; Christensen-Dalsgaard, Jørgen

    2003-05-01

    Preface; 1. A selective overview Jørgen Christensen-Dalsgaard and Michael J. Thompson; Part I. Stellar Convection and Oscillations: 2. On the diversity of stellar pulsations Wojciech A. Dziembowski; 3. Acoustic radiation and mode excitation by turbulent convection Günter Houdek; 4. Understanding roAp stars Margarida S. Cunha; 5. Waves in the magnetised solar atmosphere Colin S. Rosenthal; Part II. Stellar Rotation and Magnetic Fields: 6. Stellar rotation: a historical survey Leon Mestel; 7. The oscillations of rapidly rotating stars Michel Rieutord; 8. Solar tachocline dynamics: eddy viscosity, anti-friction, or something in between? Michael E. McIntyre; 9. Dynamics of the solar tachocline Pascale Garaud; 10. Dynamo processes: the interaction of turbulence and magnetic fields Michael Proctor; 11. Dynamos in planets Chris Jones; Part III. Physics and Structure of Stellar Interiors: 12. Solar constraints on the equation of state Werner Däppen; 13. 3He transport and the solar neutrino problem Chris Jordinson; 14. Mixing in stellar radiation zones Jean-Paul Zahn; 15. Element settling and rotation-induced mixing in slowly rotating stars Sylvie Vauclair; Part IV. Helio- and Asteroseismology: 16. Solar structure and the neutrino problem Hiromoto Shibahashi; 17. Helioseismic data analysis Jesper Schou; 18. Seismology of solar rotation Takashi Sekii; 19. Telechronohelioseismology Alexander Kosovichev; Part V. Large-Scale Numerical Experiments: 20. Bridges between helioseismology and models of convection zone dynamics Juri Toomre; 21. Numerical simulations of the solar convection zone Julian R. Elliott; 22. Modelling solar and stellar magnetoconvection Nigel Weiss; 23. Nonlinear magnetoconvection in the presence of a strong oblique field Keith Julien, Edgar Knobloch and Steven M. Tobias; 24. Simulations of astrophysical fluids Marcus Brüggen; Part VI. Dynamics: 25. A magic electromagnetic field Donald Lynden-Bell; 26. Continuum equations for stellar dynamics Edward A

  11. Chaos and Complexity in Astrophysics

    NASA Astrophysics Data System (ADS)

    Regev, Oded

    2006-03-01

    Part I. Dynamical Systems - General: 1. Introduction to Part I; 2. Astrophysical examples; 3. Mathematical properties of dynamical systems; 4. Properties of chaotic dynamics; 5. Analysis of time series; 6. Regular and irregular motion in Hamiltonian systems; 7. Extended systems - instabilities and patterns; Part II. Astrophysical Applications: 8. Introduction to Part II; 9. Planetary, stellar and galactic dynamics; 10. Irregularly variable astronomical point sources; 11. Complex spatial patterns in astrophysics; 12. Topics in astrophysical fluid dynamics; References; Index.

  12. Large Eddy Simulations in Astrophysics

    NASA Astrophysics Data System (ADS)

    Schmidt, Wolfram

    2015-12-01

    In this review, the methodology of large eddy simulations (LES) is introduced and applications in astrophysics are discussed. As theoretical framework, the scale decomposition of the dynamical equations for neutral fluids by means of spatial filtering is explained. For cosmological applications, the filtered equations in comoving coordinates are also presented. To obtain a closed set of equations that can be evolved in LES, several subgrid-scale models for the interactions between numerically resolved and unresolved scales are discussed, in particular the subgrid-scale turbulence energy equation model. It is then shown how model coefficients can be calculated, either by dynamic procedures or, a priori, from high-resolution data. For astrophysical applications, adaptive mesh refinement is often indispensable. It is shown that the subgrid-scale turbulence energy model allows for a particularly elegant and physically well-motivated way of preserving momentum and energy conservation in adaptive mesh refinement (AMR) simulations. Moreover, the notion of shear-improved models for in-homogeneous and non-stationary turbulence is introduced. Finally, applications of LES to turbulent combustion in thermonuclear supernovae, star formation and feedback in galaxies, and cosmological structure formation are reviewed.

  13. Advances IN Explosive Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Lotay, Gavin

    2016-09-01

    Breathtaking results from the Planck satellite mission and Hubble space telescope have highlighted the key role modern Astronomy is playing for our understanding of Big Bang Cosmology. However, not so widely publicized is the similar wealth of observational data now available on explosive stellar phenomena, such as X-ray bursts, novae and Supernovae. These astronomical events are responsible for the synthesis of almost all the chemical elements we find on Earth and observe in our Galaxy, as well as energy generation throughout the cosmos. Regrettably, understanding the latest collection of observational data is severely hindered by the current, large uncertainties in the underlying nuclear physics processes that drive such stellar scenarios. In order to resolve this issue, it is becoming increasingly clear that there is a need to explore the unknown properties and reactions of nuclei away from the line of stability. Consequently, state-of-the-art radioactive beam facilities have become terrestrial laboratories for the reproduction of explosive astrophysical events. In this talk, both direct and indirect methods for studying key astrophysical reactions using radioactive beams will be discussed.

  14. Polarimetry in astrophysics and cosmology

    NASA Astrophysics Data System (ADS)

    Zeng, Lingzhen

    Astrophysicists are mostly limited to passively observing electromagnetic radiation from a distance, which generally shows some degree of polarization. Polarization often carries a wealth of information on the physical state and geometry of the emitting object and intervening material. In the microwave part of the spectrum, polarization provides information about galactic magnetic fields and the physics of interstellar dust. The measurement of this polarized radiation is central to much modern astrophysical research. The first part of this thesis is about polarimetry in astrophysics. In Chapter 1, I review the basics of polarization and summarize the most important mechanisms that generate polarization in astrophysics. In Chapter 2, I describe the data analysis of polarization observation on M17 (a young, massive star formation region in the Galaxy) from Caltech Submillimeter Observatory (CSO) and show the physics that we learn about M17 from the polarimetry. Polarimetry also plays an important role in modern cosmology. Inflation theory predicts two types of polarization in the Cosmic Microwave Background (CMB) radiation, called E-modes and B-modes. Measurements to date of the E-mode signal are consistent with the predictions of anisotropic Thompson scattering, while the B-mode signal has yet to be detected. The B-mode power spectrum amplitude can be parameterized by the relative amplitude of the tensor to scalar modes r. For the simplest inflation models, the expected deviation from scale invariance (ns = 0.963 ± 0.012) is coupled to gravitational waves with r ≈ 0.1. These considerations establish a strong motivation to search for this remnant from when the universe was about 10-32 seconds old. The second part of this thesis is about the Cosmology Large Angular Scale Surveyor (CLASS) experiment, that is designed to have an unprecedented ability to detect the B-mode polarization to the level of r ≤ 0.01. Chapter 3 is an introduction to cosmology, including the

  15. High temperature geophysical instrumentation

    SciTech Connect

    Hardee, H.C.

    1988-06-01

    The instrumentation development program was to proceed in parallel with scientific research and was driven by the needs of researchers. The development of these instruments has therefore included numerous geophysical field tests, many of which have resulted in the publication of scientific articles. This paper is a brief summary of some of the major geophysical instruments that have been developed and tested under the High Temperature Geophysics Program. These instruments are briefly described and references are given for further detailed information and for scientific papers that have resulted from the use of these instruments. 9 refs., 14 figs.

  16. Fiber optic geophysical sensors

    DOEpatents

    Homuth, E.F.

    1991-03-19

    A fiber optic geophysical sensor is described in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects. 2 figures.

  17. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  18. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  19. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  20. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  1. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  2. Examples from Astrophysics in undergraduate teaching

    NASA Astrophysics Data System (ADS)

    Rastogi, Shantanu

    Physics teaching requires frequent alluding to examples and real situation where a certain concept is applicable. Astrophysics provides a variety and range of phenomena that can be recalled and explained during teaching of nearly all undergraduate branches. Sometimes these examples are the only relevant examples. To make astrophysics more accessible and attractive as a future study option, incorporating examples from astronomy and astrophysics in undergraduate Physics syllabus could be of importance. Besides common examples from mechanics and gravitation some relevant examples are enumerated that can easily be used in the classroom to both explain a concept and simultaneously introduce some astrophysical phenomenon. Some examples that could be explained or outlined are Expanding Universe in Doppler effect; stellar temperature-luminosity in blackbody radiation; gravitational lensing in image formation by converging lens; Faraday effect in polarization; Auroras and Pulsars in cyclotron; Saha’s ionization theory; Chandrasekhar’s mass Limit; Fraunhoeffer absorption lines; Forbidden spectral lines etc. The existing curriculum need not be modified - atmost some tutorials may be added. Few of these are already mentioned in the syllabus of few universities.

  3. Interdisciplinary Research Programs in Geophysical Fluid Dynamics

    DTIC Science & Technology

    2007-09-30

    scientific disciplines that deal with the dynamics of stratified fluids, rotating fluids, fluid with phase changes and non-Newtonian fluids. To formulate...clearing-house for the mathematical, experimental and computational techniques which serve astrophysics, climate science, geodynamics, meteorology and... Zika , Physical Oceanography, University of New South Wales, “The stability of cascading flows”. RESULTS The Principal Lectures and Fellows

  4. Progress in geophysical fluid dynamics

    NASA Astrophysics Data System (ADS)

    Robinson, Allan R.

    Geophysical fluid dynamics deals with the motions and physics of the atmosphere, oceans and interior of the earth and other planets: the winds, the swirls, the currents that occur on myriads of scales from millimeter to climatological. Explanations of natural phenomena, basic processes and abstractions are sought. The rotation of the earth, the buoyancy of its fluids and the tendency towards large-scale turbulence characterize these flows. But geophysical fluid dynamics is importantly a part of modern fluid dynamics which is contributing to the development of nonlinear mechanics generally. Some general insights are emerging for nonlinear systems which must be regarded as partly deterministic and partly random or which are complex and aperiodic. Contributions from geophysical fluid dynamics come from its methodology, from the experience of examples, and from the perspective provided by its unique scale. Contributions have been made to turbulent, chaotic and coherently structured nonlinear process research. Turbulent vortices larger than man himself naturally invite detailed investigation and deterministic physical studies. Examples are storms in the atmosphere and large ring vortices spun off by the Gulf Stream current in mid-ocean. The statistics of these events determine critical aspects of the general circulations. Fluid dynamicists generally now know that it is often relevant or necessary to study local dynamical processes of typical eddies even though only the average properties of the flow are of interest; progress in understanding the turbulent boundary layer in pipes involves the study of millimeter-scale vortices. Weather-related studies were seminal to the construction of the new scientific field of chaos. Coherent vortices abound of which the Great Red Spot of Jupiter is a spectacular example. Geophysical fluid dynamicists have been among forefront researchers in exploiting the steadily increasing speed and capacity of modern computers. Supercomputers

  5. Basic exploration geophysics

    SciTech Connect

    Robinson, E.S.

    1988-01-01

    An introduction to geophysical methods used to explore for natural resources and to survey earth's geology is presented in this volume. It is suitable for second-and third-year undergraduate students majoring in geology or engineering and for professional engineering and for professional engineers and earth scientists without formal instruction in geophysics. The author assumes the reader is familiar with geometry, algebra, and trigonometry. Geophysical exploration includes seismic refraction and reflection surveying, electrical resistivity and electromagnetic field surveying, and geophysical well logging. Surveying operations are described in step-by-step procedures and are illustrated by practical examples. Computer-based methods of processing and interpreting data as well as geographical methods are introduced.

  6. Hard X-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Rothschild, R. E.

    1981-01-01

    Past hard X-ray and lower energy satellite instruments are reviewed and it is shown that observation above 20 keV and up to hundreds of keV can provide much valuable information on the astrophysics of cosmic sources. To calculate possible sensitivities of future arrays, the efficiencies of a one-atmosphere inch gas counter (the HEAO-1 A-2 xenon filled HED3) and a 3 mm phoswich scintillator (the HEAO-1 A-4 Na1 LED1) were compared. Above 15 keV, the scintillator was more efficient. In a similar comparison, the sensitivity of germanium detectors did not differ much from that of the scintillators, except at high energies where the sensitivity would remain flat and not rise with loss of efficiency. Questions to be addressed concerning the physics of active galaxies and the diffuse radiation background, black holes, radio pulsars, X-ray pulsars, and galactic clusters are examined.

  7. Astrophysical terms in Armenian

    NASA Astrophysics Data System (ADS)

    Yeghikian, A. G.

    2015-07-01

    There are quite a few astrophysical textbooks (to say nothing about monographs) in Armenian, which are, however out of date and miss all the modern terms concerning space sciences. Many terms have been earlier adopted from English and, especially, from Russian. On the other hand, teachers and lecturers in Armenia need scientific terms in Armenian adequately reproducing either their means when translating from other languages or (why not) creating new ones. In short, a permanently updated astrophysical glossary is needed to serve as explanation of such terms. I am not going here to present the ready-made glossary (which should be a task for a joint efforts of many professionals) but instead just would like to describe some ambiguous examples with comments where possible coming from my long-year teaching, lecturing and professional experience. A probable connection between "iron" in Armenian as concerned to its origin is also discussed.

  8. Nuclear Astrophysics with LUNA

    NASA Astrophysics Data System (ADS)

    Broggini, Carlo

    2016-04-01

    One of the main ingredients of nuclear astrophysics is the knowledge of the thermonuclear reactions which power the stars and synthesize the chemical elements. Deep underground in the Gran Sasso Laboratory the cross section of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The main results obtained during the 'solar' phase of LUNA are reviewed and their influence on our understanding of the properties of the neutrino and of the Sun is discussed. We then describe the current LUNA program mainly devoted to the study of the nucleosynthesis of the light elements in AGB stars and Classical Novae. Finally, the future of LUNA towards the study of helium and carbon burning with a new 3.5 MV accelerator is outlined.

  9. Multiscale geophysical imaging of the critical zone

    NASA Astrophysics Data System (ADS)

    Parsekian, A. D.; Singha, K.; Minsley, B. J.; Holbrook, W. S.; Slater, L.

    2015-03-01

    Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.

  10. Phillips Laboratory Geophysics Scholar Program

    DTIC Science & Technology

    1993-09-30

    research at Phillips Laboratory . Research sponsored by Air Force Geophysics Laboratory ...Geophysics Laboratory (now the Phillips Laboratory , Geophysics Directorate), United States Air Force for its sponsorship of this research through the Air ...September 1993 Approved for public release; distribution unlimited PHILLIPS LABORATORY Directorate of Geophysics AIR FORCE MATERIEL COMMAND

  11. Birth of Neutrino Astrophysics

    SciTech Connect

    2010-05-07

    Based mainly on the results of two experiments, KamiokaNDE and Super-KamiokaNDE, the birth of neutrino astrophysics will be described. At the end, the result of the third generation Kamioka experiment, KamLAND, will be discussed together with the future possibilities.Organiser(s): Daniel Treille / EP DivisionNote: * Tea & coffee will be served at 16:00 hrs. Please note unusual day.

  12. Dark Matter Astrophysics

    NASA Astrophysics Data System (ADS)

    D'Amico, Guido; Kamionkowski, Marc; Sigurdson, Kris

    This chapter is intended to provide a brief pedagogical review of dark matter for the newcomer to the subject. We begin with a discussion of the astrophysical evidence for dark matter. The standard weakly interacting massive particle (WIMP) scenario—the motivation, particle models, and detection techniques—is then reviewed. We provide a brief sampling of some recent variations to the standard WIMP scenario, as well as some alternatives (axions and sterile neutrinos). Exercises are provided for the reader.

  13. Birth of Neutrino Astrophysics

    ScienceCinema

    None

    2016-07-12

    Based mainly on the results of two experiments, KamiokaNDE and Super-KamiokaNDE, the birth of neutrino astrophysics will be described. At the end, the result of the third generation Kamioka experiment, KamLAND, will be discussed together with the future possibilities.Organiser(s): Daniel Treille / EP DivisionNote: * Tea & coffee will be served at 16:00 hrs. Please note unusual day.

  14. GENERAL CONSIDERATIONS FOR GEOPHYSICAL METHODS APPLIED TO AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysics is the application of physical quantity measurement techniques to provide information on conditions or features beneath the earth’s surface. With the exception of borehole geophysical methods and soil probes like a cone penetrometer, these techniques are generally noninvasive with physica...

  15. Spatial scale analysis in geophysics - Integrating surface and borehole geophysics in groundwater studies

    USGS Publications Warehouse

    Paillet, Frederick L.; Singhroy V.H.Hansen D.T.Pierce R, R

    2002-01-01

    Integration of geophysical data obtained at various scales can bridge the gap between localized data from boreholes and site-wide data from regional survey profiles. Specific approaches to such analysis include: 1) comparing geophysical measurements in boreholes with the same measurement made from the surface; 2) regressing geophysical data obtained in boreholes with water-sample data from screened intervals; 3) using multiple, physically independent measurements in boreholes to develop multivariate response models for surface geophysical surveys; 4) defining subsurface cell geometry for most effective survey inversion methods; and 5) making geophysical measurements in boreholes to serve as independent verification of geophysical interpretations. Integrated analysis of surface electromagnetic surveys and borehole geophysical logs at a study site in south Florida indicates that salinity of water in the surficial aquifers is controlled by a simple wedge of seawater intrusion along the coast and by a complex pattern of upward brine seepage from deeper aquifers throughout the study area. This interpretation was verified by drilling three additional test boreholes in carefully selected locations.

  16. Geophysical investigation at Fort Detrick Maryland. Final report

    SciTech Connect

    Llopis, J.L.; Simms, J.E.

    1993-07-01

    Results of a comprehensive, integrated geophysical investigation of 15 suspected disposal areas at Area B, Fort Detrick, Maryland, are presented. Between 1943 and 1969, Fort Detrick served as the nation's center for military offensive and defensive biological research. As a result of this activity, chemically and biologically contaminated materials were generated and disposed in burial pits at Site B. Based on historical and visual information, 15 sites suspected of containing burial pits were selected to be examined in greater detail using geophysical methods. The geophysical investigations were designed to detect anomalous conditions indicative of past disposal activities. The geophysical program included electromagnetic (EM), magnetic, ground penetrating radar (GPR), and seismic refraction methods. Anomalous conditions were found at several of the sites tested and noted. The anomalous conditions may have resulted from the presence of buried material or from physical and/or chemical soil changes caused by disposal activities.... Geophysics, Electromagnetics ground penetrating radar, Geophysical surveys, Magnetics, Seismic refraction.

  17. Recent Nuclear Astrophysics Data Activities in the US

    SciTech Connect

    Bardayan, D.W.; Blackmon, J.C.; Browne, E.; Firestone, R.B.; Hale, G.M.; Hoffman, R.D.; Ma, Z.; McLane, V.; Norman, E.B.; Shu, N.; Smith, D.L.; Smith, M.S.; Van Wormer, L.A.; Woosley, S.E.; Wu, S.-C.

    1999-08-30

    Measurements in nuclear physics laboratories form the empirical foundation for new, realistic, sophisticated theoretical models of a wide variety of astrophysical systems. The predictive power of these models has, in many instances, a strong dependence on the input nuclear data, and more extensive and accurate nuclear data is required for these models than ever before. Progress in astrophysics can be aided by providing scientists with more usable, accurate, and significant amounts of nuclear data in a timely fashion in formats that can be easily incorporated into their models. A number of recent data compilations, evaluations, calculations, and disseminations that address nuclear astrophysics data needs will be described.

  18. Shape: A 3D Modeling Tool for Astrophysics.

    PubMed

    Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus

    2011-04-01

    We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.

  19. Nuclear Astrophysics Animations from the Nuclear Astrophysics Group at Clemson University

    DOE Data Explorer

    Meyer, Bradley; The, Lih-Sin

    The nuclear astrophysics group at Clemson University in South Carolina develops on-line tools and computer programs for astronomy, nuclear physics, and nuclear astrophysics. They have also done short animations that illustrate results from research with some of their tools. The animations are organized into three sections. The r-Process Movies demonstrate r-Process network calculations from the paper "Neutrino Capture and the R-Process" Meyer, McLaughlin, and Fuller, Phys. Rev. C, 58, 3696-3710 (1998). The Alpha-Rich Freezeout Movies are related to the reference: Standard alpha-rich freezeout calculation from The, Clayton, Jin, and Meyer 1998, Astrophysical Journal, "Reaction Rates Governing the Synthesis of 44Ti" At the current writing, the category for Low Metallicity s-Process Movies has only one item called n, p, 13C, 14N, 54Fe, and 88Sr Time evolution in convective zone.

  20. Turbulence in astrophysics

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.

    1990-01-01

    Some of the astrophysical scenarios in which turbulence plays an important role are discussed in view of the comparative advantages of currently available models of turbulence phenomena; attention is given to a specific model that has undergone continuous refinement since 1985. The desideratum in this inquiry is a turbulence model which incorporates the best features of an a priori deterministic model, as well as a redundant set of results from full numerical simulations for a wide variety of turbulent flows; there should also be a simplification of the former, and an enlargement of the complexities of the latter.

  1. Perspectives in astrophysical databases

    NASA Astrophysics Data System (ADS)

    Frailis, Marco; de Angelis, Alessandro; Roberto, Vito

    2004-07-01

    Astrophysics has become a domain extremely rich of scientific data. Data mining tools are needed for information extraction from such large data sets. This asks for an approach to data management emphasizing the efficiency and simplicity of data access; efficiency is obtained using multidimensional access methods and simplicity is achieved by properly handling metadata. Moreover, clustering and classification techniques on large data sets pose additional requirements in terms of computation and memory scalability and interpretability of results. In this study we review some possible solutions.

  2. Astrophysical blast wave data

    SciTech Connect

    Riley, Nathan; Geissel, Matthias; Lewis, Sean M; Porter, John L.

    2015-03-01

    The data described in this document consist of image files of shadowgraphs of astrophysically relevant laser driven blast waves. Supporting files include Mathematica notebooks containing design calculations, tabulated experimental data and notes, and relevant publications from the open research literature. The data was obtained on the Z-Beamlet laser from July to September 2014. Selected images and calculations will be published as part of a PhD dissertation and in associated publications in the open research literature, with Sandia credited as appropriate. The authors are not aware of any restrictions that could affect the release of the data.

  3. Improved Simulations of Astrophysical Plasmas: Computation of New Atomic Data

    NASA Technical Reports Server (NTRS)

    Gorczyca, Thomas W.; Korista, Kirk T.

    2005-01-01

    Our research program is designed to carry out state-of-the-art atomic physics calculations crucial to advancing our understanding of fundamental astrophysical problems. We redress the present inadequacies in the atomic data base along two important areas: dielectronic recombination and inner-shell photoionization and multiple electron ejection/Auger fluorescence therefrom. All of these data are disseminated to the astrophysical community in the proper format for implementation in spectral simulation code.

  4. Geophysical Fiber Interferometer Gyroscope.

    DTIC Science & Technology

    1979-12-31

    gravitational antenna. Basically, their device was a Twyman -Green laser interferometer that was allegedly well-isolated from its thermal and...r ~AD-AO92 913 UTAH UNIV RESEARCH INST SALT LAKE CITY GEOSPACE SCIE-EYC F/B 20/6 GEOPHYSICAL FIBER INTERFEROMETER GYROSCOPE(U) .S DEC 79 L 0 WEAVER...ACCESSION no: S, 111CIPIENT’S CATALOG NUMBER AF6ii M_ __ _ __I_ _ 4. TItLIL (eovm4jk"IU .TYEo nPaTawn.ocoet GEOPHYSICAL FIBER INTERFEROMETER GYROSCOPE. / 9

  5. Teaching oriented geophysical software

    NASA Astrophysics Data System (ADS)

    Pinto, Victor; Rivero, Lluis; Casas, Albert

    2000-08-01

    Interactive teaching techniques encourage students to adopt an active role in their education and should therefore be used at different levels of the teaching sequence. In order to mitigate the lack of educational software for Applied Geophysics, a fully interactive graphic software has been developed. The program is written in Visual Basic with some subroutines in FORTRAN and is designed for IBM-PC microcomputers using a Windows environment. The program offers the majority of the processes involved in geophysical data handling, modelling, tutorials, and instrument simulators.

  6. Physics Based University Courses

    ERIC Educational Resources Information Center

    Beeby, J. L.

    1974-01-01

    Two physics courses which serve as alternatives to general college courses in physics are outlined: physics with astrophysics and physics with electronics. Details are given of the structure of the courses and third year options are specified. (DT)

  7. High Energy Astrophysics Program (HEAP)

    NASA Technical Reports Server (NTRS)

    Angelini, Lorella; Corcoran, Michael; Drake, Stephen; McGlynn, Thomas A.; Snowden, Stephen; Mukai, Koji; Cannizzo, John; Lochner, James; Rots, Arnold; Christian, Eric; Barthelmy, Scott; Palmer, David; Mitchell, John; Esposito, Joseph; Sreekumar, P.; Hua, Xin-Min; Mandzhavidze, Natalie; Chan, Kai-Wing; Soong, Yang; Barrett, Paul

    1998-01-01

    This report reviews activities performed by the members of the USRA contract team during the 6 months of the reporting period and projected activities during the coming 6 months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in astrophysics. Supported missions include advanced Satellite for Cosmology and Astrophysics (ASCA), X-Ray Timing Experiment (XTE), X-Ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC) and others.

  8. High Energy Astrophysics Program (HEAP)

    NASA Technical Reports Server (NTRS)

    Angelini, L.

    1998-01-01

    This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

  9. The Fermilab Particle Astrophysics Center

    SciTech Connect

    Not Available

    2004-11-01

    The Particle Astrophysics Center was established in fall of 2004. Fermilab director Michael S. Witherell has named Fermilab cosmologist Edward ''Rocky'' Kolb as its first director. The Center will function as an intellectual focus for particle astrophysics at Fermilab, bringing together the Theoretical and Experimental Astrophysics Groups. It also encompasses existing astrophysics projects, including the Sloan Digital Sky Survey, the Cryogenic Dark Matter Search, and the Pierre Auger Cosmic Ray Observatory, as well as proposed projects, including the SuperNova Acceleration Probe to study dark energy as part of the Joint Dark Energy Mission, and the ground-based Dark Energy Survey aimed at measuring the dark energy equation of state.

  10. Mathematical and physical ideas for climate science

    NASA Astrophysics Data System (ADS)

    Lucarini, Valerio; Blender, Richard; Herbert, Corentin; Ragone, Francesco; Pascale, Salvatore; Wouters, Jeroen

    2014-12-01

    The climate is a forced and dissipative nonlinear system featuring nontrivial dynamics on a vast range of spatial and temporal scales. The understanding of the climate's structural and multiscale properties is crucial for the provision of a unifying picture of its dynamics and for the implementation of accurate and efficient numerical models. We present some recent developments at the intersection between climate science, mathematics, and physics, which may prove fruitful in the direction of constructing a more comprehensive account of climate dynamics. We describe the Nambu formulation of fluid dynamics and the potential of such a theory for constructing sophisticated numerical models of geophysical fluids. Then, we focus on the statistical mechanics of quasi-equilibrium flows in a rotating environment, which seems crucial for constructing a robust theory of geophysical turbulence. We then discuss ideas and methods suited for approaching directly the nonequilibrium nature of the climate system. First, we describe some recent findings on the thermodynamics of climate, characterize its energy and entropy budgets, and discuss related methods for intercomparing climate models and for studying tipping points. These ideas can also create a common ground between geophysics and astrophysics by suggesting general tools for studying exoplanetary atmospheres. We conclude by focusing on nonequilibrium statistical mechanics, which allows for a unified framing of problems as different as the climate response to forcings, the effect of altering the boundary conditions or the coupling between geophysical flows, and the derivation of parametrizations for numerical models.

  11. The Nuclear Astrophysics Explorer

    NASA Technical Reports Server (NTRS)

    Matteson, James L.; Teegarden, B. J.; Gehrels, Neil; Mahoney, William A.

    1990-01-01

    The Nuclear Astrophysics Explorer (NAE) is a concept for a possible future NASA Explorer mission which would obtain high resolution, E/Delta E about 500, observations of gamma-ray lines in order to study many fundamental problems in astrophysics. It operates from 15 keV to 10 MeV with a 3-sigma sensitivity of about 3 x 10 to the -6th ph/sq cm-s in a 10 to the 6th s observation. This is 100 times below the presently known gamma-ray line fluxes. The NAE uses a heavily shielded array of nine cooled Ge detectors in a very low background configuration. Its 10-deg field of view contains a versatile coded mask system which provides 2D imaging with 4-deg resolution, 1D imaging with 2-deg resolution and efficient measurements of emission from diffuse and point sources. The late 1990s is the earliest the NAE mission could begin. The scientific motivation, instrument concept, mission concept and expected results, and status and plans for the NAE are presented.

  12. Towards the Astrophysical Cyberspace

    NASA Astrophysics Data System (ADS)

    Richmond, Alan

    We are accustomed to thinking of user interfaces in terms of screens, keyboards, and relatively local applications. Our user conducts a dialog with our application through the mechanisms we provide; at their simplest, these are just reads and writes built into our chosen programming language. With the advent of bit-mapped graphical workstations, seamless network integration, and several other exciting new technologies, we are going to witness a profound change in this viewpoint. We look at possible futures for astrophysical user interfaces, ranging from the use of GUI builders, through hypertext and multimedia, to virtual reality scenarios. We will show that the trend is to increasing transparency, so that the user interface will become less and less of an obvious intermediary, and more of a `looking glass' into astrophysical datascapes and cyberspaces. Examples will be presented of user interfaces available now, that begin to demonstrate these trends. Our primary example is HEASARC's StarTrax, which will provide access to many services, i.e. bulletins, catalogs, proposal and analysis tools, initially for the ROSAT MIPS (Mission Information and Planning System), later for the Next Generation Browse. Thanks are due to Nick White of the HEASARC/ASCA-GOF NASA/GSFC for initiating and supporting the StarTrax user interface development project.

  13. Eclipsing Binaries as Astrophysical Laboratories: CM Draconis - Accurate Absolute Physical Properties of Low Mass Stars and an Independent Estimate of the Primordial Helium Abundance

    NASA Astrophysics Data System (ADS)

    McCook, G. P.; Guinan, E. F.; Saumon, D.; Kang, Y. W.

    1997-05-01

    CM Draconis (Gl 630.1; Vmax = +12.93) is an important eclipsing binary consisting of two dM4.5e stars with an orbital period of 1.2684 days. This binary is a high velocity star (s= 164 km/s) and the brighter member of a common proper motion pair with a cool faint white dwarf companion (LP 101-16). CM Dra and its white dwarf companion were once considered by Zwicky to belong to a class of "pygmy stars", but they turned out to be ordinary old, cool white dwarfs or faint red dwarfs. Lacy (ApJ 218,444L) determined the first orbital and physical properties of CM Dra from the analysis of his light and radial velocity curves. In addition to providing directly measured masses, radii, and luminosities for low mass stars, CM Dra was also recognized by Lacy and later by Paczynski and Sienkiewicz (ApJ 286,332) as an important laboratory for cosmology, as a possible old Pop II object where it may be possible to determine the primordial helium abundance. Recently, Metcalfe et al.(ApJ 456,356) obtained accurate RV measures for CM Dra and recomputed refined elements along with its helium abundance. Starting in 1995, we have been carrying out intensive RI photoelectric photometry of CM Dra to obtain well defined, accurate light curves so that its fundamental properties can be improved, and at the same time, to search for evidence of planets around the binary from planetary transit eclipses. During 1996 and 1997 well defined light curves were secured and these were combined with the RV measures of Metcalfe et al. (1996) to determine the orbital and physical parameters of the system, including a refined orbital period. A recent version of the Wilson-Devinney program was used to analyze the data. New radii, masses, mean densities, Teff, and luminosities were found as well as a re-determination of the helium abundance (Y). The results of the recent analyses of the light and RV curves will be presented and modelling results discussed. This research is supported by NSF grants AST-9315365

  14. Mini-conference and Related Sessions on Laboratory Plasma Astrophysics

    SciTech Connect

    Hantao Ji

    2004-02-27

    This paper provides a summary of some major physics issues and future perspectives discussed in the Mini-Conference on Laboratory Plasma Astrophysics. This Mini-conference, sponsored by the Topical Group on Plasma Astrophysics, was held as part of the American Physical Society's Division of Plasma Physics 2003 Annual Meeting (October 27-31, 2003). Also included are brief summaries of selected talks on the same topic presented at two invited paper sessions (including a tutorial) and two contributed focus oral sessions, which were organized in coordination with the Mini-Conference by the same organizers.

  15. Terrestrial Planet Geophysics

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.

    2008-12-01

    Terrestrial planet geophysics beyond our home sphere had its start arguably in the early 1960s, with Keith Runcorn contending that the second-degree shape of the Moon is due to convection and Mariner 2 flying past Venus and detecting no planetary magnetic field. Within a decade, in situ surface geophysical measurements were carried out on the Moon with the Apollo program, portions of the lunar magnetic and gravity fields were mapped, and Jack Lorell and his colleagues at JPL were producing spherical harmonic gravity field models for Mars using tracking data from Mariner 9, the first spacecraft to orbit another planet. Moreover, Mariner 10 discovered a planetary magnetic field at Mercury, and a young Sean Solomon was using geological evidence of surface contraction to constrain the thermal evolution of the innermost planet. In situ geophysical experiments (such as seismic networks) were essentially never carried out after Apollo, although they were sometimes planned just beyond the believability horizon in planetary mission queues. Over the last three decades, the discipline of terrestrial planet geophysics has matured, making the most out of orbital magnetic and gravity field data, altimetric measurements of surface topography, and the integration of geochemical information. Powerful constraints are provided by tectonic and volcanic information gleaned from surface images, and the engagement of geologists in geophysical exercises is actually quite useful. Accompanying these endeavors, modeling techniques, largely adopted from the Earth Science community, have become increasingly sophisticated and have been greatly enhanced by the dramatic increase in computing power over the last two decades. The future looks bright with exciting new data sets emerging from the MESSENGER mission to Mercury, the promise of the GRAIL gravity mission to the Moon, and the re-emergence of Venus as a worthy target for exploration. Who knows? With the unflagging optimism and persistence

  16. Important plasma problems in astrophysics

    SciTech Connect

    Kulsrud, R.M.

    1995-01-01

    In astrophysics, plasmas occur under very extreme conditions. For example there are ultra strong 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 Reynold`s 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. I will describe one of the more exciting examples. I will attempt to convey the excitement I felt when I was first exposed to it. However, not all plasma astrophysical phenomena are so simple. There are certain important plasma phenomena in astrophysics, which 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. I 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-Reynold`s-number MHD dynamos.

  17. Nuclear Astrophysics with the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Spitaleri, Claudio

    2015-04-01

    In stars nuclear reactions take place at physical conditions that make very hard their measurements in terrestrial laboratories. Indeed in astrophysical environments nuclear reactions between charged nuclei occur at energies much lower than the Coulomb barrier and the corresponding cross section values lie in the nano or picobarn regime, that makes their experimental determination extremely difficult. This is due to the very small barrier Coulomb penetration factor, which produces an exponential fall off of the cross section as a function of energy. Additionally, the presence of the electron screening needs to be properly taken into account when dealing with cross section measurements at low-energies. The Trojan Horse Method (THM) represents an independent experimental technique, allowing one to measure astrophysical S(E)-factor bared from both Coulomb penetration and electron screening effects. The main advantages and the most recent results are here shown and discussed.

  18. Numerical relativity beyond astrophysics.

    PubMed

    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.

  19. Black-hole astrophysics

    SciTech Connect

    Bender, P.; Bloom, E.; Cominsky, L.

    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.

  20. Theoretical Particle Astrophysics

    SciTech Connect

    Kamionkowski, Marc

    2013-08-07

    Abstract: Theoretical Particle Astrophysics The research carried out under this grant encompassed work on the early Universe, dark matter, and dark energy. We developed CMB probes for primordial baryon inhomogeneities, primordial non-Gaussianity, cosmic birefringence, gravitational lensing by density perturbations and gravitational waves, and departures from statistical isotropy. We studied the detectability of wiggles in the inflation potential in string-inspired inflation models. We studied novel dark-matter candidates and their phenomenology. This work helped advance the DoE's Cosmic Frontier (and also Energy and Intensity Frontiers) by finding synergies between a variety of different experimental efforts, by developing new searches, science targets, and analyses for existing/forthcoming experiments, and by generating ideas for new next-generation experiments.

  1. Beauty and Astrophysics

    NASA Astrophysics Data System (ADS)

    Bessell, Michael S.

    2000-08-01

    Spectacular colour images have been made by combining CCD images in three different passbands using Adobe Photoshop. These beautiful images highlight a variety of astrophysical phenomena and should be a valuable resource for science education and public awareness of science. The wide field images were obtained at the Siding Spring Observatory (SSO) by mounting a Hasselblad or Nikkor telephoto lens in front of a 2K × 2K CCD. Options of more than 30 degrees or 6 degrees square coverage are produced in a single exposure in this way. Narrow band or broad band filters were placed between lens and CCD enabling deep, linear images in a variety of passbands to be obtained. We have mapped the LMC and SMC and are mapping the Galactic Plane for comparison with the Molonglo Radio Survey. Higher resolution images have also been made with the 40 inch telescope of galaxies and star forming regions in the Milky Way.

  2. Astrophysics Faces the Millennium

    NASA Astrophysics Data System (ADS)

    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?

  3. Numerical relativity beyond astrophysics

    NASA Astrophysics Data System (ADS)

    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.

  4. A German Geophysics School Project First steps to bring geophysical topics to schoolclasses

    NASA Astrophysics Data System (ADS)

    Schneider, S.

    2002-12-01

    In Germany Geophysics is a science with almost none or a bad reputation. People do not know to distinguish between Geophysics, Geography and Geology. In order to change the public view on Geosciences, a,School Project Geophysics' is going to be created at the Institute of Meteorology and Geophysics, Johann Wolfgang Goethe University, Frankfurt, which will offer geophysical ideas, methodes and scientific results to schoolclasses. After researches like PISA or TIMSS (third international Math and Nature-Science test) new concepts in education will be required. Interdisciplinary tasks are demanded by national and international commissions.\\The,School Project Geophysics' will be created to bring geophysical themes and results of scientific research into schools. One Day- or one Week-Workshops will help to publish geophysical contents in close cooperation with Physics - and Geography - teachers.\\Hands-on experiments (for advanced pupils) like refraction-Seismics or Magnetic measurements will lead students closer to scientific work and will help to establish personal interests in Earthsciences. Working with personally produced datasets will show the basics of inversion theory and point out the difficulties in creating models. Boundaries of data interpretation (the plurality of variables needed) will teach the school children to see scientific and statistic predictions and declarations more criticaly. Animations and Videos will present global examples (for example of volcanoes or Earthquakes) and lead over to regional sites. Excursions to these sites will help to show fieldwork methods and its problems and will convince to take a different look on topography and landscapes.\\All necessary utilities (Animations, Videos, Pictures and foils) will be offered to teachers in an online-data base which will be installed and managed by the project. Teachers and pupils might get easily into contact with Scientists to discuss geoscientific items. Further on extensions to geographic

  5. Laboratory Plasma Astrophysics Research with Intense Lasers

    NASA Astrophysics Data System (ADS)

    Takabe, Hideaki; Kato, Tsunehiko; Kuramitsu, Yasuhiro; Sakawa, Yuichi

    2008-12-01

    Large scale laser facilities mainly constructed for fusion research can be used to produce high-energy-density plasmas like the interior of stars and planets. They can be also used to reproduce the extreme phenomena of explosion and high Mach number flow in mimic scale in laboratory. With advanced diagnostic technique, we can study the physics of plasma phenomena expected to control a variety of phenomena in Universe. The subjects studied so far are reviewed, for example, in [1], [2]. The project to promote the laboratory astrophysics with Gekko XII laser facility has been initiated from April 1st this year as a project of our institute. It consists of four sub-projects. They are 1. Physics of collisionless shock and particle acceleration, 2. Physics of Non LTE (local thermodynamic equilibrium) photo-ionized plasma, 3. Physics of planets and meteor impact, 4. Development of superconducting Terahertz device. I will briefly explain what the laser astrophysics means and introduce what are the targets of our project. Regarding the first sub-project, we have carried out hydrodynamic and PIC simulation to design the experiments with intense laser. We clarified the physical mechanism of generation of the magnetic field in non-magnetized plasma and the collsionless shock formation caused by the ion orbit modifications by the magnetic fields generated as the result of plasma instability. Note from Publisher: This article contains the abstract only.

  6. Geophysical Models for Nuclear Explosion Monitoring

    SciTech Connect

    Pasyanos, M E; Walter, W R; Flanagan, M

    2003-07-16

    Geophysical models are increasingly recognized as an important component of regional calibrations for seismic monitoring. The models can be used to predict geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. While empirical measurements of these geophysical parameters might be preferred, in aseismic regions or regions without seismic stations, this data might not exist. In these cases, models represent a 'best guess' of the seismic properties in a region, which improves on global models such as the PREM (Preliminary Reference Earth Model) or the IASPEI (International Association of Seismology and Physics of the Earth's Interior) models. The model-based predictions can also serve as a useful background for the empirical measurements by removing trends in the data. To this end, Lawrence Livermore National Laboratory (LLNL) has developed the WENA model for Western Eurasia and North Africa. This model is constructed using a regionalization of several dozen lithospheric (crust and uppermost mantle) models, combined with the Laske sediment model and 3SMAC upper mantle. We have evaluated this model using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis. Similarly, Los Alamos National Laboratory (LANL) has developed a geophysical model for East Asia, allowing LLNL/LANL to construct a model for all of Eurasia and North Africa. These models continue to evolve as new and updated datasets are used to critically assess the predictive powers of the model. Research results from this meeting and other reports and papers can be used to update and refine the regional boundaries and regional models. A number of other groups involved in monitoring have also developed geophysical models. As these become available, we will be assessing the models and their constitutive components for their suitability for inclusion in the National Nuclear Security

  7. Two LANL laboratory astrophysics experiments

    SciTech Connect

    Intrator, Thomas P.

    2014-01-24

    Two laboratory experiments are described that have been built at Los Alamos (LANL) to gain access to a wide range of fundamental plasma physics issues germane to astro, space, and fusion plasmas. The overarching theme is magnetized plasma dynamics which includes significant currents, MHD forces and instabilities, magnetic field creation and annihilation, sheared flows and shocks. The Relaxation Scaling Experiment (RSX) creates current sheets and flux ropes that exhibit fully 3D dynamics, and can kink, bounce, merge and reconnect, shred, and reform in complicated ways. Recent movies from a large data set describe the 3D magnetic structure of a driven and dissipative single flux rope that spontaneously self-saturates a kink instability. Examples of a coherent shear flow dynamo driven by colliding flux ropes will also be shown. The Magnetized Shock Experiment (MSX) uses Field reversed configuration (FRC) experimental hardware that forms and ejects FRCs at 150km/sec. This is sufficient to drive a collision less magnetized shock when stagnated into a mirror stopping field region with Alfven Mach number MA=3 so that super critical shocks can be studied. We are building a plasmoid accelerator to drive Mach numbers MA >> 3 to access solar wind and more exotic astrophysical regimes. Unique features of this experiment include access to parallel, oblique and perpendicular shocks, shock region much larger than ion gyro radii and ion inertial length, room for turbulence, and large magnetic and fluid Reynolds numbers.

  8. Relativistic opacities for astrophysical applications

    DOE PAGES

    Fontes, Christopher John; Fryer, Christopher Lee; Hungerford, Aimee L.; ...

    2015-06-29

    Here, we report on the use of the Los Alamos suite of relativistic atomic physics codes to generate radiative opacities for the modeling of astrophysically relevant plasmas under local thermodynamic equilibrium (LTE) conditions. The atomic structure calculations are carried out in fine-structure detail, including full configuration interaction. Three example applications are considered: iron opacities at conditions relevant to the base of the solar convection zone, nickel opacities for the modeling of stellar envelopes, and samarium opacities for the modeling of light curves produced by neutron star mergers. In the first two examples, comparisons are made between opacities that are generatedmore » with the fully and semi-relativistic capabilities in the Los Alamos suite of codes. As expected for these highly charged, iron-peak ions, the two methods produce reasonably similar results, providing confidence that the numerical methods have been correctly implemented. However, discrepancies greater than 10% are observed for nickel and investigated in detail. In the final application, the relativistic capability is used in a preliminary investigation of the complicated absorption spectrum associated with cold lanthanide elements.« less

  9. Relativistic opacities for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Fontes, C. J.; Fryer, C. L.; Hungerford, A. L.; Hakel, P.; Colgan, J.; Kilcrease, D. P.; Sherrill, M. E.

    2015-09-01

    We report on the use of the Los Alamos suite of relativistic atomic physics codes to generate radiative opacities for the modeling of astrophysically relevant plasmas under local thermodynamic equilibrium (LTE) conditions. The atomic structure calculations are carried out in fine-structure detail, including full configuration interaction. Three example applications are considered: iron opacities at conditions relevant to the base of the solar convection zone, nickel opacities for the modeling of stellar envelopes, and samarium opacities for the modeling of light curves produced by neutron star mergers. In the first two examples, comparisons are made between opacities that are generated with the fully and semi-relativistic capabilities in the Los Alamos suite of codes. As expected for these highly charged, iron-peak ions, the two methods produce reasonably similar results, providing confidence that the numerical methods have been correctly implemented. However, discrepancies greater than 10% are observed for nickel and investigated in detail. In the final application, the relativistic capability is used in a preliminary investigation of the complicated absorption spectrum associated with cold lanthanide elements.

  10. Relativistic opacities for astrophysical applications

    SciTech Connect

    Fontes, Christopher John; Fryer, Christopher Lee; Hungerford, Aimee L.; Hakel, Peter; Colgan, James Patrick; Kilcrease, David Parker; Sherrill, Manalo Edgar

    2015-06-29

    Here, we report on the use of the Los Alamos suite of relativistic atomic physics codes to generate radiative opacities for the modeling of astrophysically relevant plasmas under local thermodynamic equilibrium (LTE) conditions. The atomic structure calculations are carried out in fine-structure detail, including full configuration interaction. Three example applications are considered: iron opacities at conditions relevant to the base of the solar convection zone, nickel opacities for the modeling of stellar envelopes, and samarium opacities for the modeling of light curves produced by neutron star mergers. In the first two examples, comparisons are made between opacities that are generated with the fully and semi-relativistic capabilities in the Los Alamos suite of codes. As expected for these highly charged, iron-peak ions, the two methods produce reasonably similar results, providing confidence that the numerical methods have been correctly implemented. However, discrepancies greater than 10% are observed for nickel and investigated in detail. In the final application, the relativistic capability is used in a preliminary investigation of the complicated absorption spectrum associated with cold lanthanide elements.

  11. Asteroid Surface Geophysics

    NASA Astrophysics Data System (ADS)

    Murdoch, N.; Sánchez, P.; Schwartz, S. R.; Miyamoto, H.

    The regolith-covered surfaces of asteroids preserve records of geophysical processes that have occurred both at their surfaces and sometimes also in their interiors. As a result of the unique microgravity environment that these bodies possess, a complex and varied geophysics has given birth to fascinating features that we are just now beginning to understand. The processes that formed such features were first hypothesized through detailed spacecraft observations and have been further studied using theoretical, numerical, and experimental methods that often combine several scientific disciplines. These multiple approaches are now merging toward a further understanding of the geophysical states of the surfaces of asteroids. In this chapter we provide a concise summary of what the scientific community has learned so far about the surfaces of these small planetary bodies and the processes that have shaped them. We also discuss the state of the art in terms of experimental techniques and numerical simulations that are currently being used to investigate regolith processes occurring on small-body surfaces and that are contributing to the interpretation of observations and the design of future space missions.

  12. Hydrodynamic Scalings: from Astrophysics to Laboratory

    NASA Astrophysics Data System (ADS)

    Ryutov, D. D.; Remington, B. A.

    2000-05-01

    A surprisingly general hydrodynamic similarity has been recently described in Refs. [1,2]. One can call it the Euler similarity because it works for the Euler equations (with MHD effects included). Although the dissipation processes are assumed to be negligible, the presence of shocks is allowed. For the polytropic medium (i.e., the medium where the energy density is proportional to the pressure), an evolution of an arbitrarily chosen 3D initial state can be scaled to another system, if a single dimensionless parameter (the Euler number) is the same for both initial states. The Euler similarity allows one to properly design laboratory experiments modeling astrophysical phenomena. We discuss several examples of such experiments related to the physics of supernovae [3]. For the problems with a single spatial scale, the condition of the smallness of dissipative processes can be adequately described in terms of the Reynolds, Peclet, and magnetic Reynolds numbers related to this scale (all three numbers must be large). However, if the system develops small-scale turbulence, dissipation may become important at these smaller scales, thereby affecting the gross behavior of the system. We analyze the corresponding constraints. We discuss also constraints imposed by the presence of interfaces between the substances with different polytropic index. Another set of similarities governs evolution of photoevaporation fronts in astrophysics. Convenient scaling laws exist in situations where the density of the ablated material is very low compared to the bulk density. We conclude that a number of hydrodynamical problems related to such objects as the Eagle Nebula can be adequately simulated in the laboratory. We discuss also possible scalings for radiative astrophysical jets (see Ref. [3] and references therein). This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract W-7405-Eng-48

  13. Studying Nuclear Astrophysics at NIF

    SciTech Connect

    Boyd, R; Bernstein, L; Brune, C

    2009-07-01

    measurements of some of the nuclear reaction probabilities that are important to nuclear astrophysics, the field that relates energy production and nucleosynthesis from nuclear reactions in stars and in the Big Bang to the environments in which those nuclear reactions occur. NIF, unlike previous nuclear-physics facilities, will enable measurements of nuclear reactions at the temperatures, densities, and ionization states similar to those that occur in stars.

  14. Theoretically Palatable Flavor Combinations of Astrophysical Neutrinos.

    PubMed

    Bustamante, Mauricio; Beacom, John F; Winter, Walter

    2015-10-16

    The flavor composition of high-energy astrophysical neutrinos can reveal the physics governing their production, propagation, and interaction. The IceCube Collaboration has published the first experimental determination of the ratio of the flux in each flavor to the total. We present, as a theoretical counterpart, new results for the allowed ranges of flavor ratios at Earth for arbitrary flavor ratios in the sources. Our results will allow IceCube to more quickly identify when their data imply standard physics, a general class of new physics with arbitrary (incoherent) combinations of mass eigenstates, or new physics that goes beyond that, e.g., with terms that dominate the Hamiltonian at high energy.

  15. Theoretically Palatable Flavor Combinations of Astrophysical Neutrinos

    NASA Astrophysics Data System (ADS)

    Bustamante, Mauricio; Beacom, John F.; Winter, Walter

    2015-10-01

    The flavor composition of high-energy astrophysical neutrinos can reveal the physics governing their production, propagation, and interaction. The IceCube Collaboration has published the first experimental determination of the ratio of the flux in each flavor to the total. We present, as a theoretical counterpart, new results for the allowed ranges of flavor ratios at Earth for arbitrary flavor ratios in the sources. Our results will allow IceCube to more quickly identify when their data imply standard physics, a general class of new physics with arbitrary (incoherent) combinations of mass eigenstates, or new physics that goes beyond that, e.g., with terms that dominate the Hamiltonian at high energy.

  16. Effect of solar activity and geophysical disturbance on physical-chemical processes in liquid medium: Preliminary analysis of storm-glass activity

    NASA Astrophysics Data System (ADS)

    Baranovsky, E. A.; Tarashchuk, V. P.; Vladimirsky, B. M.

    2010-12-01

    Changes in the state of a solution in storm glasses (Fitzroy retort) have been recorded by measuring the height of the level of crystals. Devices manufactured by a group of Crimean researchers have been used to measure these characteristics daily since 1995. Fragments of an accumulated observation dataset have been processed employing standard meteorological and cosmophysical indices. It is found that, 2-3 days before isolated sharp drops in the atmospheric pressure, crystal formation intensifies synchronously in two devices. A relationship is found between the activity under study and changes in the A p geomagnetic-disturbance index and the flare-intensity index. There is a set of quasi-stable periods in variations of the activity of storm glasses, of which the 120-, 185-, and 360-day periods are most significant. The obtained results are generally consistent with views that changes in the background electromagnetic low-frequency fields are a physical agent influencing the process of crystal formation.

  17. Resonant Compton Physics for Magnetar Astrophysics

    NASA Astrophysics Data System (ADS)

    Ickes, Jesse; Gonthier, Peter L.; Eiles, Matthew; Baring, Matthew G.

    2016-01-01

    Various telescopes including RXTE, INTEGRAL, Suzaku, and Fermi have detected steady non-thermal X-ray emission in the 10 - 200 keV band from strongly magnetic neutron stars known as magnetars. Magnetic inverse Compton scattering is believed to be the leading candidate for the production of this intense X-ray radiation. Scattering at ultra-relativistic energies leads to attractive simplifications in the analytics of the magnetic Compton cross section. We have recently addressed such a case by developing compact analytic expressions using correct spin-dependent widths acquired through the implementation of Sokolov & Ternov basis states, focusing specifically on ground-state-ground-state scattering. Compton scattering in magnetar magnetospheres can cool electrons down to mildly relativistic energies. Moreover, soft gamma-ray flaring in magnetars may involve strong Comptonization in expanding clouds of mildly relativistic pairs. Such environs necessitate the development of more general magnetic scattering cross sections, in which the incoming photons acquire substantial incident angles relative to the field in the rest frame of the electron leading to arbitrary Landau excitations of the intermediate and final states. Due to the rapid transitions of the excited-state to the ground-state, the initial electron is still assumed to be in the ground state. The cross sections treat the plethora of harmonic resonances associated with various cyclotron transitions between Landau states. Polarization and spin dependence of the cross section for the four scattering modes is compared to the cross section obtained with spin-averaged widths. We present numerical results to show the comparisons to highlight the role of the spin-dependent widths of the resonances. The findings presented here will have applications to various neutron star problems, including computation of Eddington luminosities and polarization mode-switching rates in transient magnetar fireballs.

  18. Topics in physics and astrophysics of LIGO

    NASA Astrophysics Data System (ADS)

    Levin, Yuri

    1999-12-01

    This thesis deals with three topics, all of which are related to the generation or detection of gravitational waves: I. The standard quantum limit (SQL) for LIGO and quantum non- demolition (QND) measurements, which allow one to overcome the SQL. Two particular QND measurement schemes are considered: (i)a Speed Meter; and (ii)the Braginsky-Khalili nonlinear meter (BK- meter). Our analysis shows that (a)Using the Speed Meter one can perform naturally a broad- band QND measurement of a force acting on the test mass. (b)The BK-meter can provide a natural way to perform a narrow-band QND measurement of a force acting on the mirrors of the optical cavity. While neither of these QND measurement schemes can be immediately implemented for LIGO, they might provide conceptual steps towards the design of a practical QND interferometer. II. Mechanical thermal noise in LIGO. We develop a new method of calculating thermal noise in mechanical systems, which is based on a direct application of the Fluctuation-Dissipation theorem. This method is capable of handling mechanical systems with inhomogeneous dissipation. We apply our direct method to an internal thermal noise in LIGO test masses. We find that: (a)The test-mass surface defects will make a larger contribution to thermal noise than was previously inferred. (b)Our direct method is more precise and computationally less expensive for small beam sizes than the previous mode-sum method. We also apply our direct method of analysis to suspension thermal noise in LIGO. We find that by positioning the laser beam spot on the mirror face and by monitoring the motion of the suspension wires, it may be possible to reduce the suspension thermal noise by a factor ~ 100. III. R-modes in neutron stars (NS) in low-mass x-ray binaries (LMXBs). We study the suggestion that the accretion of gas onto a neutron star in an LMXB triggers an instability in which the star's r- modes are amplified by gravitational-wave emission. We find that if this is the case, then the subsequent neutron-star evolution depends critically on whether the neutron-star viscosity decreases with temperature, or is temperature-independent. In the former case, the Neutron Star goes through runaway cycles of rapid ( ~ 1 month) heating-rapid ( ~ 1 month) spindown-slow ( ~ 105 years) cooling-slow ( ~ 106 years) spin-up. In the latter (temperature-independent) case, the Neutron Star probably settles down into an equilibrium state with constant spin rate and temperature, and becomes a steady emitter of gravitational waves. All of the chapters in this thesis, except the introductory chapter I, have been published or are in press. (Abstract shortened by UMI.)

  19. Simple analytic model for astrophysical S factors

    SciTech Connect

    Yakovlev, D. G.; Beard, M.; Gasques, L. R.; Wiescher, M.

    2010-10-15

    We propose a physically transparent analytic model of astrophysical S factors as a function of a center-of-mass energy E of colliding nuclei (below and above the Coulomb barrier) for nonresonant fusion reactions. For any given reaction, the S(E) model contains four parameters [two of which approximate the barrier potential, U(r)]. They are easily interpolated along many reactions involving isotopes of the same elements; they give accurate practical expressions for S(E) with only several input parameters for many reactions. The model reproduces the suppression of S(E) at low energies (of astrophysical importance) due to the shape of the low-r wing of U(r). The model can be used to reconstruct U(r) from computed or measured S(E). For illustration, we parametrize our recent calculations of S(E) (using the Sao Paulo potential and the barrier penetration formalism) for 946 reactions involving stable and unstable isotopes of C, O, Ne, and Mg (with nine parameters for all reactions involving many isotopes of the same elements, e.g., C+O). In addition, we analyze astrophysically important {sup 12}C+{sup 12}C reaction, compare theoretical models with experimental data, and discuss the problem of interpolating reliably known S(E) values to low energies (E < or approx. 2-3 MeV).

  20. Goddard's Astrophysics Science Division Annual Report 2011

    NASA Technical Reports Server (NTRS)

    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.

  1. Reaction Rate Parameterization for Nuclear Astrophysics Research

    NASA Astrophysics Data System (ADS)

    Scott, J. P.; Lingerfelt, E. J.; Smith, M. S.; Hix, W. R.; Bardayan, D. W.; Sharp, J. E.; Kozub, R. L.; Meyer, R. A.

    2004-11-01

    Libraries of thermonuclear reaction rates are used in element synthesis models of a wide variety of astrophysical phenomena, such as exploding stars and the inner workings of our sun. These computationally demanding models are more efficient when libraries, which may contain over 60000 rates and vary by 20 orders of magnitude, have a uniform parameterization for all rates. We have developed an on-line tool, hosted at www.nucastrodata.org, to obtain REACLIB parameters (F.-K. Thielemann et al., Adv. Nucl. Astrophysics 525, 1 (1987)) that represent reaction rates as a function of temperature. This helps to rapidly incorporate the latest nuclear physics results in astrophysics models. The tool uses numerous techniques and algorithms in a modular fashion to improve the quality of the fits to the rates. Features, modules, and additional applications of this tool will be discussed. * Managed by UT-Battelle, LLC, for the U.S. D.O.E. under contract DE-AC05-00OR22725 + Supported by U.S. D.O.E. under Grant No. DE-FG02-96ER40955

  2. Goddard's Astrophysics Science Division Annual Report 2013

    NASA Technical Reports Server (NTRS)

    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.

  3. The Astrophysics Science Division Annual Report 2009

    NASA Technical Reports Server (NTRS)

    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.

  4. Byurakan Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Mickaelian, A. M.

    2016-09-01

    This booklet is devoted to NAS RA V. Ambartsumian Byurakan Astrophysical Observatory and is aimed at people interested in astronomy and BAO, pupils and students, BAO visitors and others. The booklet is made as a visiting card and presents concise and full information about BAO. A brief history of BAO, the biography of the great scientist Viktor Ambartsumian, brief biographies of 13 other deserved scientists formerly working at BAO (B.E. Markarian, G.A. Gurzadyan, L.V. Mirzoyan, M.A. Arakelian, et al.), information on BAO telescopes (2.6m, 1m Schmidt, etc.) and other scientific instruments, scientific library and photographic plate archive, Byurakan surveys (including the famous Markarian Survey included in the UNESCO Memory of the World International Register), all scientific meetings held in Byurakan, international scientific collaboration, data on full research staff of the Observatory, as well as former BAO researchers, who have moved to foreign institutions are given in the booklet. At the end, the list of the most important books published by Armenian astronomers and about them is given.

  5. Numerical Relativity and Astrophysics

    NASA Astrophysics Data System (ADS)

    Lehner, Luis; Pretorius, Frans

    2014-08-01

    Throughout the Universe many powerful events are driven by strong gravitational effects that require general relativity to fully describe them. These include compact binary mergers, black hole accretion, and stellar collapse, where velocities can approach the speed of light and extreme gravitational fields (ΦNewt/c2≃1) mediate the interactions. Many of these processes trigger emission across a broad range of the electromagnetic spectrum. Compact binaries further source strong gravitational wave emission that could directly be detected in the near future. This feat will open up a gravitational wave window into our Universe and revolutionize our understanding of it. Describing these phenomena requires general relativity, and—where dynamical effects strongly modify gravitational fields—the full Einstein equations coupled to matter sources. Numerical relativity is a field within general relativity concerned with studying such scenarios that cannot be accurately modeled via perturbative or analytical calculations. In this review, we examine results obtained within this discipline, with a focus on its impact in astrophysics.

  6. Fifteen Years of Laboratory Astrophysics at Ames

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.; Salama, F.; Hudgins, D. M.; Bernstein, M.; Goorvitch, David (Technical Monitor)

    1998-01-01

    Tremendous strides have been made in our understanding of interstellar material over the past fifteen years thanks to significant, parallel developments in two closely related areas: observational astronomy and laboratory astrophysics. Fifteen years ago the composition of interstellar dust was largely guessed at, the concept of ices in dense molecular clouds ignored, and the notion of large, abundant, gas phase, carbon-rich molecules widespread throughout the interstellar medium (ISM) considered impossible. Today the composition of dust in the diffuse ISM is reasonably well constrained to cold refractory materials comprised of amorphous and crystalline silicates mixed with an amorphous carbonaceous material containing aromatic structural units and short, branched aliphatic chains. In the dense ISM, these cold dust particles are coated with mixed-molecular ices whose compositions are very well known. Lastly, the signature of carbon-rich polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by early interstellar chemistry standards, is widespread throughout the ISM. This great progress has only been made possible by the close collaboration of laboratory experimentalists with observers and theoreticians, all with the goal of applying their skills to astrophysical problems of direct interest to NASA programs. Such highly interdisciplinary collaborations ensure fundamental, in depth coverage of the wide-ranging challenges posed by astrophysics. These challenges include designing astrophysically focused experiments and data analysis, tightly coupled with astrophysical searches spanning 2 orders of magnitude in wavelength, and detailed theoretical modeling. The impact of our laboratory has been particularly effective as there is constant cross-talk and feedback between quantum theorists; theoretical astrophysicists and chemists; experimental physicists; organic, physical and petroleum chemists; and infrared and UV/Vis astronomers. In this paper, two examples

  7. Radiative capture reactions in astrophysics

    DOE PAGES

    Brune, Carl R.; Davids, Barry

    2015-08-07

    Here, the radiative capture reactions of greatest importance in nuclear astrophysics are identified and placed in their stellar contexts. Recent experimental efforts to estimate their thermally averaged rates are surveyed.

  8. Astrophysics and Cosmology

    NASA Astrophysics Data System (ADS)

    Henneaux, Marc

    The following sections are included: * The Opening Session was held in the Gracious Presence of His Royal Highness Philippe, King of the Belgians. * Opening Address by David Gross, Chair of the Solvay Scientific Committee for Physics * Opening Address by Roger Blandford, Chair of the 26th Solvay Conference of Physics * Address by Thomas Hertog, Georges Lemaître: A Visionary Belgian Cosmologist

  9. An introduction to modern astrophysics and cosmology

    NASA Astrophysics Data System (ADS)

    Carroll, Bradley W.; Ostlie, Dale A.

    2006-07-01

    "An introduction to modern astrophysics, 2nd Edition" has been thoroughly revised to reflect the dramatic changes and advancements in astrophysics that have occurred over the past decade. This book has been updated to include the latest results from relevant fields of astrophysics and advances in our theoretical understanding of astrophysical phenomena.

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

    ERIC Educational Resources Information Center

    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…

  11. High energy particles and quanta in astrophysics

    NASA Technical Reports Server (NTRS)

    Mcdonald, F. B. (Editor); Fichtel, C. E.

    1974-01-01

    The various subdisciplines of high-energy astrophysics are surveyed in a series of articles which attempt to give an overall view of the subject as a whole by emphasizing the basic physics common to all fields in which high-energy particles and quanta play a role. Successive chapters cover cosmic ray experimental observations, the abundances of nuclei in the cosmic radiation, cosmic electrons, solar modulation, solar particles (observation, relationship to the sun acceleration, interplanetary medium), radio astronomy, galactic X-ray sources, the cosmic X-ray background, and gamma ray astronomy. Individual items are announced in this issue.

  12. Women in Physics.

    ERIC Educational Resources Information Center

    Roth, Laura M.; O'Fallon, Nancy M.

    This booklet presents information about career opportunities for women in physics. Included are summaries of research areas in physics (optical physics, solid-state physics, materials science, nuclear physics, high-energy physics, astrophysics, cryogenics, plasma physics, biophysics, atmospheric physics) and differences between theory and…

  13. Preliminary geological investigation of the Bir Hayzan diatomite deposit, Kingdom of Saudi Arabia, with a section on selected physical properties and implications for future geophysical exploration

    USGS Publications Warehouse

    Whitney, J.W.; Gettings, M.E.

    1982-01-01

    diatom association and further laboratory testing of physical properties of the diatomite also should be made. Further exploration in the Nafud is recommended to locate other possible diatomite deposits.

  14. Computational astrophysics: Pulsating stars

    NASA Astrophysics Data System (ADS)

    Davis, C. G.

    The field of computational astrophysics in pulsating star studies has grown considerably since the advent of the computer. Initially calculations were done on the IBM 704 with 32K of memory and now we use the CRAY YMP computers with considerably more memory. Our early studies were for models of pulsating stars using a 1D Lagrangian hydrodynamic code (SPEC) with radiation diffusion. The radiative transfer was treated in the equilibrium diffusion approximation and the hydrodynamics was done utilizing the approximation of artificial viscosity. The early calculations took many hours of 704 CPU time. Early in 1965 we decided to improve on the usual treatment of the radiative transfer used in our codes by utilizing the method of moments, the so-called variable Eddington approximation. In this approximation the material energy field is uncoupled from the radiation energy field and the angular dependence is introduced through the Eddington factor. A multigroup frequency dependent method may also be applied. The Eddington factor is determined by snapshots of the stars structure utilizing a y-line approximation. The full radiative transfer approximation appears necessary in order to understand the light curves for W Virginia stars and may be important for the light curves of RR Lyrae stars. A detailed radiative transfer method does not appear to be necessary for the understanding of Cepheid light curves. A recent improvement to our models for pulsating stars is in the use of an adaptive mesh scheme to resolve the sharp features in the nonlinear hydrodynamic structure. From these improved structures, better analysis of the radius, velocity, and light curves could be obtained.

  15. Astrometry for Astrophysics

    NASA Astrophysics Data System (ADS)

    van Altena, William F.

    Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. Statistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts, history and necessity C. López; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

  16. Astrometry for Astrophysics

    NASA Astrophysics Data System (ADS)

    van Altena, William F.

    2012-11-01

    Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. StaStatistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts , history and necessity C. Löpez; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

  17. Magnetized Astrophysical Flows

    NASA Astrophysics Data System (ADS)

    Russo, Matthew

    2016-08-01

    This thesis combines two studies of astrophysical flows in which magnetic fields play a dominant role. The first concerns outflows from compact objects in which plasma is accelerated to highly relativistic speeds by strong, ordered magnetic fields. We generalize the theory of relativistic, ideal magnetohydrodynamic (MHD) outflows by including an intense radiation source as is likely to occur in gamma-ray bursts (GRBs). This represents a hybrid of the traditional fireball and electromagnetic models of GRBs, which posit respectively that the acceleration is accomplished by thermal pressure or magnetic stresses. We find that acceleration is more efficient and occurs over a larger range of radii than in a pure Poynting jet. We also uncover a distinct observational signature in the emitted spectrum when the Poynting flux exceeds the radiation energy flux due to the Compton up-scattering of photons within the relativistic flow. We then turn to study the accretion of magnetized protoplanetary disks (PPDs) in which the assumptions of ideal MHD begin to break down due to the low level of ionization. We develop a novel model that prescribes the profiles of the magnetic field and mass flux in PPDs by tying them to the field of a magnetized, radial protostellar wind. We find that the inner disk is more strongly magnetized and thus supports a higher accretion rate by both large scale stresses and turbulence driven by the magnetorotational instability (MRI). This leads to an inside-out clearing of the inner disk that stalls at a low column density when particles are lofted from the midplane to higher altitudes where they suppress MRI turbulence. We calculate the long-term evolution of such a disk and show that the migration of planets is significantly slowed (or reversed), perhaps alleviating one of the central problems concerning the formation of planetary systems.

  18. Acceleration in astrophysics

    SciTech Connect

    Colgate, S.A.

    1993-12-31

    The origin of cosmic rays and applicable laboratory experiments are discussed. Some of the problems of shock acceleration for the production of cosmic rays are discussed in the context of astrophysical conditions. These are: The presumed unique explanation of the power law spectrum is shown instead to be a universal property of all lossy accelerators; the extraordinary isotropy of cosmic rays and the limited diffusion distances implied by supernova induced shock acceleration requires a more frequent and space-filling source than supernovae; the near perfect adiabaticity of strong hydromagnetic turbulence necessary for reflecting the accelerated particles each doubling in energy roughly 10{sup 5} to {sup 6} scatterings with negligible energy loss seems most unlikely; the evidence for acceleration due to quasi-parallel heliosphere shocks is weak. There is small evidence for the expected strong hydromagnetic turbulence, and instead, only a small number of particles accelerate after only a few shock traversals; the acceleration of electrons in the same collisionless shock that accelerates ions is difficult to reconcile with the theoretical picture of strong hydromagnetic turbulence that reflects the ions. The hydromagnetic turbulence will appear adiabatic to the electrons at their much higher Larmor frequency and so the electrons should not be scattered incoherently as they must be for acceleration. Therefore the electrons must be accelerated by a different mechanism. This is unsatisfactory, because wherever electrons are accelerated these sites, observed in radio emission, may accelerate ions more favorably. The acceleration is coherent provided the reconnection is coherent, in which case the total flux, as for example of collimated radio sources, predicts single charge accelerated energies much greater than observed.

  19. Geophysics publications honored

    NASA Astrophysics Data System (ADS)

    Geophysics and geology publications by the U.S. Geological Survey were awarded one first- and two third-place prizes at the ‘Blue Pencil’ ceremony last month, sponsored by the National Association of Government Communicators.First place in the news release category went to Frank Forrester, an AGU member and recently retired USGS information officer. Editors and artists of the bimonthly USGS Earthquake Information Bulletin were awarded third place in the category for technical magazines using at least two colors.

  20. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  1. Fundamentals of Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    McWilliams, James C.

    2006-07-01

    Earth's atmosphere and oceans exhibit complex patterns of fluid motion over a vast range of space and time scales. These patterns combine to establish the climate in response to solar radiation that is inhomogeneously absorbed by the materials comprising air, water, and land. Spontaneous, energetic variability arises from instabilities in the planetary-scale circulations, appearing in many different forms such as waves, jets, vortices, boundary layers, and turbulence. Geophysical fluid dynamics (GFD) is the science of all these types of fluid motion. This textbook is a concise and accessible introduction to GFD for intermediate to advanced students of the physics, chemistry, and/or biology of Earth's fluid environment. The book was developed from the author's many years of teaching a first-year graduate course at the University of California, Los Angeles. Readers are expected to be familiar with physics and mathematics at the level of general dynamics (mechanics) and partial differential equations. Covers the essential GFD required for atmospheric science and oceanography courses Mathematically rigorous, concise coverage of basic theory and applications to both oceans and atmospheres Author is a world expert; this book is based on the course he has taught for many years Exercises are included, with solutions available to instructors from solutions@cambridge.org

  2. New Advances in the Trojan Horse Method as an Indirect Approach to Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; Cherubini, S.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartà, R.

    2013-05-01

    With the introduction of the Trojan Horse Method, nuclear cross sections between charged particles at astrophysical energies can now be measured. Here the basic features of the method are recalled together with recent results relevant for Nuclear Astrophysics. New applications in connection with plasma physics and industrial energy production are discussed.

  3. Magnetic helicity in astrophysical dynamos

    NASA Astrophysics Data System (ADS)

    Candelaresi, Simon

    2012-09-01

    The broad variety of ways in which magnetic helicity affects astrophysical systems, in particular dynamos, is discussed. The so-called alpha effect is responsible for the growth of large-scale magnetic fields. The conservation of magnetic helicity, however, quenches the alpha effect, in particular for high magnetic Reynolds numbers. Predictions from mean-field theories state particular power law behavior of the saturation strength of the mean fields, which we confirm in direct numerical simulations. The loss of magnetic helicity in the form of fluxes can alleviate the quenching effect, which means that large-scale dynamo action is regained. Physically speaking, galactic winds or coronal mass ejections can have fundamental effects on the amplification of galactic and solar magnetic fields. The gauge dependence of magnetic helicity is shown to play no effect in the steady state where the fluxes are represented in form of gauge-independent quantities. This we demonstrate in the Weyl-, resistive- and pseudo Lorentz-gauge. Magnetic helicity transport, however, is strongly affected by the gauge choice. For instance the advecto-resistive gauge is more efficient in transporting magnetic helicity into small scales, which results in a distinct spectrum compared to the resistive gauge. The topological interpretation of helicity as linking of field lines is tested with respect to the realizability condition, which imposes a lower bound for the spectral magnetic energy in presence of magnetic helicity. It turns out that the actual linking does not affect the relaxation process, unlike the magnetic helicity content. Since magnetic helicity is not the only topological variable, I conduct a search for possible others, in particular for non-helical structures. From this search I conclude that helicity is most of the time the dominant restriction in field line relaxation. Nevertheless, not all numerical relaxation experiments can be described by the conservation of magnetic helicity

  4. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    NASA Astrophysics Data System (ADS)

    Abbas, M.; Jardani, A.

    2015-12-01

    The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

  5. Experiences and prospects of nuclear astrophysics in underground laboratories

    SciTech Connect

    Junker, M.

    2014-05-09

    Impressive progress has been made in the course the last decades in understanding astrophysical objects. Increasing precision of nuclear physics data has contributed significantly to this success, but now a better understanding of several important findings is frequently limited by uncertainties related to the available nuclear physics data. Consequently it is desirable to improve significantly the quality of these data. An important step towards higher precision is an excellent signal to background ratio of the data. Placing an accelerator facility inside an underground laboratory reducing the cosmic ray induced background by six orders of magnitude is a powerful method to reach this goal, even though careful reduction of environmental and beam induced background must still be considered. Experience in the field of underground nuclear astrophysics has been gained since 20 years due to the pioneering work of the LUNA Collaboration (Laboratory for Underground Nuclear Astrophysics) operating inside the underground laboratories of the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Based on the success of this work presently also several other projects for underground laboratories dedicated to nuclear astrophysics are being pursued worldwide. This contribution will give a survey of the past experience in underground nuclear astrophysics as well as an outlook on future developments.

  6. MODULES FOR EXPERIMENTS IN STELLAR ASTROPHYSICS (MESA)

    SciTech Connect

    Paxton, Bill; Bildsten, Lars; Dotter, Aaron; Herwig, Falk; Lesaffre, Pierre; Timmes, Frank

    2011-01-15

    Stellar physics and evolution calculations enable a broad range of research in astrophysics. Modules for Experiments in Stellar Astrophysics (MESA) is a suite of open source, robust, efficient, thread-safe libraries for a wide range of applications in computational stellar astrophysics. A one-dimensional stellar evolution module, MESAstar, combines many of the numerical and physics modules for simulations of a wide range of stellar evolution scenarios ranging from very low mass to massive stars, including advanced evolutionary phases. MESAstar solves the fully coupled structure and composition equations simultaneously. It uses adaptive mesh refinement and sophisticated timestep controls, and supports shared memory parallelism based on OpenMP. State-of-the-art modules provide equation of state, opacity, nuclear reaction rates, element diffusion data, and atmosphere boundary conditions. Each module is constructed as a separate Fortran 95 library with its own explicitly defined public interface to facilitate independent development. Several detailed examples indicate the extensive verification and testing that is continuously performed and demonstrate the wide range of capabilities that MESA possesses. These examples include evolutionary tracks of very low mass stars, brown dwarfs, and gas giant planets to very old ages; the complete evolutionary track of a 1 M {sub sun} star from the pre-main sequence (PMS) to a cooling white dwarf; the solar sound speed profile; the evolution of intermediate-mass stars through the He-core burning phase and thermal pulses on the He-shell burning asymptotic giant branch phase; the interior structure of slowly pulsating B Stars and Beta Cepheids; the complete evolutionary tracks of massive stars from the PMS to the onset of core collapse; mass transfer from stars undergoing Roche lobe overflow; and the evolution of helium accretion onto a neutron star. MESA can be downloaded from the project Web site (http://mesa.sourceforge.net/).

  7. Simulating Astrophysical Jets in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bellan, Paul

    2004-11-01

    A laboratory plasma configuration based on spheromak [1] magnetic fusion plasma physics technology is used to simulate many important features of magnetically driven astrophysical jets. The experimental sequence starts with a quasi-static seed poloidal magnetic field that links a central disk electrode to a co-planar bounding annular electrode; this arrangement provides a topology analogous to the poloidal magnetic field of a star linking a surrounding accretion disk. After puffing neutral gas from nozzles mounted on the electrodes, plasma is created via application of a large emf between the central disk and the bounding annular electrode. The emf then drives a large poloidal electric current flowing from the central disk electrode (star) to the annulus (accretion disk) along the bias poloidal magnetic field. This electric current produces large magnetohydrodynamic forces which result in dynamics analogous to the dynamics of an astrophysical jet. In particular, the laboratory "astrophysical jet" is observed [2,3] to evolve through a distinct, reproducible sequence consisting of jet formation, collimation, kink instability, and for appropriate parameters, detachment into an unbounded, expanding spheromak-like plasmoid. These observations and related observations on a solar prominence simulation experiment [4] have motivated an analytic model [5] for the collimation physics whereby stagnation of convected, frozen-in toroidal magnetic flux amplifies the toroidal magnetic flux density and then, since the toroidal magnetic field (i.e., toroidal flux density) provides the pinch force, the pinch force is increased, collimating the jet. The following talk (You, Bellan, Yun) will present detailed measurements of the jet formation, acceleration, and collimation process. [1] P. M. Bellan, Spheromaks (Imperial College Press, London, 2000). [2] S. C. Hsu and P. M. Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002). [3] S. C. Hsu and P. M. Bellan, Phys. Rev. Letters 90, article

  8. BOOK REVIEW: Particle Astrophysics (Second Edition)

    NASA Astrophysics Data System (ADS)

    Bell, Nicole

    2009-07-01

    Particle astrophysics, the interface of elementary particle physics with astrophysics and cosmology, is a rapidly evolving field. Perkins' book provides a nice introduction to this field, at a level appropriate for senior undergraduate students. Perkins develops the foundations underlying both the particle and astrophysics areas, and also covers some of the most recent developments in this field. The latter is an appealing feature, as students rarely encounter topics of current research in their undergraduate textbooks. Part 1 of the text introduces the elementary particle content, and interactions, of the standard model of particle physics. Relativity is addressed at the level of special relativistic kinematics, the equivalence principle and the Robertson-Walker metric. Part 2 covers cosmology, starting with the expansion of the Universe and basic thermodynamics. It then moves on to primordial nucleosynthesis, baryogenesis, dark matter, dark energy, structure formation and the cosmic microwave background. Part 3 covers cosmic rays, stellar evolution, and related topics. Cutting edge topics include the use of the cosmological large scale structure power spectrum to constrain neutrino mass, the creation of the baryon asymmetry via leptogenesis, and the equation of state for dark energy. While the treatment of many topics is quite brief, the level of depth is about right for undergraduates who are being exposed to these topics for the first time. The breadth of topics spanned is excellent. Perkins does a good job connecting theory with the experimental underpinnings, and of simplifying the theoretical presentation of complex subjects to a level that senior undergraduate students should find accessible. Each chapter includes a number of exercises. Brief solutions are provided for all the exercises, while fully worked solutions are provided for a smaller subset.

  9. Goddard's Astrophysics Science Divsion Annual Report 2014

    NASA Technical Reports Server (NTRS)

    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

  10. Topics in theoretical astrophysics

    NASA Astrophysics Data System (ADS)

    Li, Chao

    This thesis presents a study of various interesting problems in theoretical astrophysics, including gravitational wave astronomy, gamma ray bursts and cosmology. Chapters 2, 3 and 4 explore prospects for detecting gravitational waves from stellar-mass compact objects spiraling into intermediate-mass black holes with ground-based observatories. It is shown in chapter 2 that if the central body is not a BH but its metric is stationary, axisymmetric, reflection symmetric and asymptotically flat, then the waves will likely be triperiodic, as for a BH. Chapters 3 and 4 show that the evolutions of the waves' three fundamental frequencies and of the complex amplitudes of their spectral components encode (in principle) details of the central body's metric, the energy and angular momentum exchange between the central body and the orbit, and the time-evolving orbital elements. Chapter 5 studies a local readout method to enhance the low frequency sensitivity of detuned signal-recycling interferometers. We provide both the results of improvement in quantum noise and the implementation details in Advanced LIGO. Chapter 6 applies and generalizes causal Wiener filter to data analysis in macroscopic quantum mechanical experiments. With the causal Wiener filter method, we demonstrate that in theory we can put the test masses in the interferometer to its quantum mechanical ground states. Chapter 7 presents some analytical solutions for expanding fireballs, the common theoretical model for gamma ray bursts and soft gamma ray repeaters. We apply our results to SGR 1806-20 and rediscover the mismatch between the model and the afterglow observations. Chapter 8 discusses the reconstruction of the scalar-field potential of the dark energy. We advocate direct reconstruction of the scalar field potential as a way to minimize prior assumptions on the shape, and thus minimize the introduction of bias in the derived potential. Chapter 9 discusses gravitational lensing modifications to cosmic

  11. Geophysical fluid dynamics: whence, whither and why?

    PubMed Central

    2016-01-01

    This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena—the Gulf Stream, for example—something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future. PMID:27616918

  12. Geophysical fluid dynamics: whence, whither and why?

    NASA Astrophysics Data System (ADS)

    Vallis, Geoffrey K.

    2016-08-01

    This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena-the Gulf Stream, for example-something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future.

  13. Influences of the astrophysical environment on nuclear decay rates

    SciTech Connect

    Norman, E.B.

    1987-09-01

    In many astronomical environments, physical conditions are so extreme that nuclear decay rates can be significantly altered from their laboratory values. Such effects are relevant to a number of current problems in nuclear astrophysics. Experiments related to these problems are now being pursued, and will be described in this talk. 19 refs., 5 figs.

  14. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    SciTech Connect

    Yoneda, K.

    2012-11-12

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  15. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    NASA Astrophysics Data System (ADS)

    Yoneda, K.

    2012-11-01

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  16. Art as a Vehicle for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    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.

  17. The geophysical impact of the Aristoteles mission

    NASA Astrophysics Data System (ADS)

    Anderson, Allen Joel; Klingele, E.; Sabadini, R.; Tinti, S.; Zerbini, Suzanna

    1991-12-01

    The importance of a precise, high resolution gradiometric and magnetometric mission in some topics of geophysical interest is stressed. Ways in which the planned Aristoteles mission can allow the geophysical community to improve the knowledge and the physical understanding of several important geodynamical processes involving the coupled system consisting of the lithosphere, asthenosphere and upper mantle are discussed. Particular attention is devoted to the inversion of anomalous density structures in collision and subduction zones by means of the joint use of gradiometric and seismic tomographic data. Some modeling efforts accomplished to study the capability of the mission to invert the rheological parameters of the lithosphere and upper mantle through the gravimetric signals of internal and surface density anomalies are described.

  18. Sampling functions for geophysics

    NASA Technical Reports Server (NTRS)

    Giacaglia, G. E. O.; Lunquist, C. A.

    1972-01-01

    A set of spherical sampling functions is defined such that they are related to spherical-harmonic functions in the same way that the sampling functions of information theory are related to sine and cosine functions. An orderly distribution of (N + 1) squared sampling points on a sphere is given, for which the (N + 1) squared spherical sampling functions span the same linear manifold as do the spherical-harmonic functions through degree N. The transformations between the spherical sampling functions and the spherical-harmonic functions are given by recurrence relations. The spherical sampling functions of two arguments are extended to three arguments and to nonspherical reference surfaces. Typical applications of this formalism to geophysical topics are sketched.

  19. The Next Century Astrophysics Program

    NASA Technical Reports Server (NTRS)

    Swanson, Paul N.

    1991-01-01

    The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of major and moderate missions that are presently under study for flight sometime within the next 20 years. These programs include the: Advanced X Ray Astrophysics Facility; X Ray Schmidt Telescope; Nuclear Astrophysics Experiment; Hard X Ray Imaging Facility; Very High Throughput Facility; Gamma Ray Spectroscopy Observatory; Hubble Space Telescope; Lunar Transit Telescope; Astrometric Interferometer Mission; Next Generation Space Telescope; Imaging Optical Interferometer; Far Ultraviolet Spectroscopic Explorer; Gravity Probe B; Laser Gravity Wave Observatory in Space; Stratospheric Observatory for Infrared Astronomy; Space Infrared Telescope Facility; Submillimeter Intermediate Mission; Large Deployable Reflector; Submillimeter Interferometer; and Next Generation Orbiting Very Long Baseline Interferometer.

  20. Storage ring mass spectrometry for nuclear structure and astrophysics research

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Litvinov, Yu A.; Uesaka, T.; Xu, H. S.

    2016-07-01

    In the last two and a half decades ion storage rings have proven to be powerful tools for precision experiments with unstable nuclides in the realm of nuclear structure and astrophysics. There are presently three storage ring facilities in the world at which experiments with stored radioactive ions are possible. These are the ESR in GSI, Darmstadt/Germany, the CSRe in IMP, Lanzhou/China, and the R3 storage ring in RIKEN, Saitama/Japan. In this work, an introduction to the facilities is given. Selected characteristic experimental results and their impact in nuclear physics and astrophysics are presented. Planned technical developments and the envisioned future experiments are outlined.

  1. AXAF: The Advanced X-Ray Astrophysics Facility

    NASA Technical Reports Server (NTRS)

    Pellerin, Charles J.; Weisskopf, Martin C.; Neal, Valerie

    2005-01-01

    X-rays are produced by violent, energetic, and explosive phenomena in the universe. The Advanced X-Ray Astrophysics Facility (AXAF) is an orbiting observatory designed to view these X-rays. The National Academy of Sciences Survey Committee on Astronomy and Astrophysics has recommended AXAF as the #1 priority among all major new astronomy programs. The scientific importance of AXAF was also highlighted by the Academy's Survey Committee on Physics. Why has AXAF earned such enthusiastic support, not only among astronomers, but also broadly within the nation's scientific community?

  2. Pulsar extinction. [astrophysics

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.; Baker, K.; Turk, J. S.

    1975-01-01

    Radio emission from pulsars, attributed to an instability associated with the creation of electron-positron pairs from gamma rays was investigated. The condition for pair creation therefore lead to an extinction condition. The relevant physical processes were analyzed in the context of a mathematical model, according to which radiation originated at the polar caps and magnetic field lines changed from a closed configuration to an open configuration at the force balance or corotation radius.

  3. Nuclear astrophysics lessons from INTEGRAL.

    PubMed

    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.

  4. Nuclear astrophysics and electron beams

    SciTech Connect

    Schwenk, A.

    2013-11-07

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  5. Experimental High Energy Neutrino Astrophysics

    SciTech Connect

    Distefano, Carla

    2005-10-12

    Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

  6. Feds fund geophysical energy research

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Amid the current confusion surrounding the pending fate of the United States Department of Energy (President Reagan proposed a plan to ‘dismantle’ it), a rather large program, sometimes called ‘Physical Research in the Geosciences,’ survives in financially healthy condition. According to the recent report ‘Summary Outline of DOE Geoscience and Geoscience-Related Research (DOE/ER-0120, Feb. 1982), the amount of funding granted to university researchers for the current fiscal year is $16 million.In a procedure similar to other federal government unsolicited grant research proplate grams, funds are awarded to successful university applicants on the basis of research proposals. An interesting note is that apparently because of the uncertainties surrounding the futures of several federal programs, including the DOE, some researchers have assumed, incorrectly, that many sources of research funding may be discontinued. Meanwhile, program directors of the National Science Foundation have told Eos that their programs are experiencing a large increase in research proposals because investigators are apparently seeking other sources of funding. As the Office of Management Budget request for fiscal year 1983 stands at the present time, funding for geophysical energy research will be increased substantially under the Office of Basic Energy Sciences.

  7. Distance Measurement Solves Astrophysical Mysteries

    NASA Astrophysics Data System (ADS)

    2003-08-01

    distance. "Our measurements showed that the pulsar is about 950 light-years from Earth, essentially the same distance as the supernova remnant," said Steve Thorsett, of the University of California, Santa Cruz. "That means that the two almost certainly were created by the same supernova blast," he added. With that problem solved. the astronomers then turned to studying the pulsar's neutron star itself. Using a variety of data from different telescopes and armed with the new distance measurement, they determined that the neutron star is between 16 and 25 miles in diameter. In such a small size, it packs a mass roughly equal to that of the Sun. The next result of learning the pulsar's actual distance was to provide a possible answer to a longstanding question about cosmic rays. Cosmic rays are subatomic particles or atomic nuclei accelerated to nearly the speed of light. Shock waves in supernova remnants are thought to be responsible for accelerating many of these particles. Scientists can measure the energy of cosmic rays, and had noted an excess of such rays in a specific energy range. Some researchers had suggested that the excess could come from a single supernova remnant about 1000 light-years away whose supernova explosion was about 100,000 years ago. The principal difficulty with this suggestion was that there was no accepted candidate for such a source. "Our measurement now puts PSR B0656+14 and the Monogem Ring at exactly the right place and at exactly the right age to be the source of this excess of cosmic rays," Brisken said. With the ability of the VLBA, one of the telescopes of the NRAO, to make extremely precise position measurements, the astronomers expect to improve the accuracy of their distance determination even more. "This pulsar is becoming a fascinating laboratory for studying astrophysics and nuclear physics," Thorsett said. In addition to Brisken and Thorsett, the team of astronomers includes Aaron Golden of the National University of Ireland, Robert

  8. Astrobites: Engaging Undergraduate Science Majors with Current Astrophysical Research

    NASA Astrophysics Data System (ADS)

    Zevin, Michael; Astrobites

    2017-01-01

    Astrobites is a graduate-student organization that publishes an online astrophysical literature blog (astrobites.com). The purpose of the site is to make current astrophysical research accessible to and exciting for undergraduate physical science majors and astronomy enthusiasts, and the site now hosts an archive of over 1300 posts summarizing recent astrophysical research. In addition, Astrobites presents posts on career guidance, practical 'how-to' articles, conference summaries, and astronomy news. Astrobites has an average of more than 1000 pageviews per day and reaches not only its target audience of undergraduates, but also graduate students and professionals within astronomy, astronomy enthusiasts, and educators. As we enter our seventh year of successful blogging, we share here the most up-to-date summary of our organization, readership, and growth.

  9. Nuclear Astrophysics at DANCE

    SciTech Connect

    Reifarth, R.; Bredeweg, T.A.; Esch, E.-I.; Haight, R.C.; Kronenberg, A.; O'Donnell, J.M.; Rundberg, R.S.; Schwantes, J.M.; Ullmann, J.L.; Vieira, D.J.; Wouters, J.M.; Alpizar-Vicente, A.; Hatarik, R.; Greife, U.

    2005-05-24

    One of the most interesting nuclear physics challenges is obtaining a detailed understanding of the nucleosynthesis processes of the elements. Knowledge about the stellar sites, and how they are governed by stellar evolution and cosmology are crucial in understanding the overall picture. Information on reaction rates for neutron- and charged-particle-induced reactions have a direct impact on existing stellar models. Except for the stable isotopes, very few neutron-induced reactions in the energy range of interest have been measured to date. DANCE measurements on stable and unstable isotopes will provide many of the missing key reactions that are needed to understand the nucleosynthesis of the heavy elements.

  10. Ninety Years of International Cooperation in Geophysics

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A.; Beer, T.

    2009-05-01

    Because applicable physical, chemical, and mathematical studies of the Earth system must be both interdisciplinary and international, the International Union of Geodesy and Geophysics (IUGG) was formed in 1919 as an non-governmental, non-profit organization dedicated to advancing, promoting, and communicating knowledge of the Earth system, its space environment, and the dynamical processes causing change. The Union brings together eight International Associations that address different disciplines of Earth sciences. Through these Associations, IUGG promotes and enables studies in the geosciences by providing a framework for collaborative research and information exchange, by organizing international scientific assemblies worldwide, and via research publications. Resolutions passed by assemblies of IUGG and its International Associations set geophysical standards and promote issues of science policy on which national members agree. IUGG has initiated and/or vigorously supported collaborative international efforts that have led to highly productive worldwide interdisciplinary research programs, such as the International Geophysical Year and subsequent International Years (IPY, IYPE, eGY, and IHY), International Lithosphere Programme, World Climate Research Programme, Geosphere-Biosphere Programme, and Integrated Research on Risk Disaster. IUGG is inherently involved in the projects and programs related to climate change, global warming, and related environmental impacts. One major contribution has been the creation, through the International Council for Science (ICSU), of the World Data Centers and the Federation of Astronomical and Geophysical Data Analysis Services. These are being transformed to the ICSU World Data System, from which the data gathered during the major programs and data products will be available to researchers everywhere. IUGG cooperates with UNESCO, WMO, and some other U.N. and non-governmental organizations in the study of natural catastrophes

  11. Lecture Notes and Essays in Astrophysics. II Astrophysics Symposium of the GEA-RSEF.

    NASA Astrophysics Data System (ADS)

    Ulla, Ana; Manteiga, Minia

    2006-12-01

    This second volume of "Lecture Notes and Essays in Astrophysics" contains a selection of lectures on a variety of topics that contribute to illustrate the current healthy state of Spanish Astrophysics. The first "lecture notes" review two space projects with a relevant participation from the Spanish Astrophysical community, CoRoT and Cassini-Huygens missions. The present-day knowledge about Titan, the solar system object with a physical environment most similar to that at Earth, is carefully revised in a pleasant lecture by Luisa María Lara, Rafael Rodrigo and José Juan López Moreno. The recent success in the launching and operativity of the CoRoT mission increases even more the interest of the review by Rafael Garrido and Hans J. Deeg illustrating the search for exoplanets by the CoRoT satellite. The potential discovery of Earth-like planets around other stars will need, apart from sophisticated technological development, the design of techniques for identifying the most representative parameters of their atmospheres and surfaces. Manuel Vazquez, P. Montañés Rodríguez and E. Pallé, review the main results of observations and simulations looking at our planet with low or null resolution, in other words, considering the Earth as an exoplanet. Our aim is to offer the specialized public, and particularly to graduate and postgraduate astrophysics students, selected comprehensive reviews on hot topics lectured by expert researchers on the subject ("Lecture Notes"). As in the first volume of the series, this issue is complemented by a set of chapters on more specific topics ("Essays").

  12. Indirect methods in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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.

  13. Condensation Processes in Astrophysical Environments

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A., III; Rietmeijer, Frans J. M.; Hill, Hugh G. M.

    2002-01-01

    Astrophysical systems present an intriguing set of challenges for laboratory chemists. Chemistry occurs in regions considered an excellent vacuum by laboratory standards and at temperatures that would vaporize laboratory equipment. Outflows around Asymptotic Giant Branch (AGB) stars have timescales ranging from seconds to weeks depending on the distance of the region of interest from the star and, on the way significant changes in the state variables are defined. The atmospheres in normal stars may only change significantly on several billion-year timescales. Most laboratory experiments carried out to understand astrophysical processes are not done at conditions that perfectly match the natural suite of state variables or timescales appropriate for natural conditions. Experimenters must make use of simple analog experiments that place limits on the behavior of natural systems, often extrapolating to lower-pressure and/or higher-temperature environments. Nevertheless, we argue that well-conceived experiments will often provide insights into astrophysical processes that are impossible to obtain through models or observations. This is especially true for complex chemical phenomena such as the formation and metamorphism of refractory grains under a range of astrophysical conditions. Data obtained in our laboratory has been surprising in numerous ways, ranging from the composition of the condensates to the thermal evolution of their spectral properties. None of this information could have been predicted from first principals and would not have been credible even if it had.

  14. International Olympiad on Astronomy and Astrophysics

    ERIC Educational Resources Information Center

    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.)

  15. Symposium on Recent Results in Infrared Astrophysics

    NASA Technical Reports Server (NTRS)

    Dyal, P. (Editor)

    1977-01-01

    Abstracts of papers presented at a symposium titled Recent Results in Infrared Astrophysics are set forth. The abstracts emphasize photometric, spectroscopic, polarization, and theoretical results on a broad range of current topics in infrared astrophysics.

  16. Introducing Astrophysics Research to High School Students.

    ERIC Educational Resources Information Center

    Etkina, Eugenia; Lawrence, Michael; Charney, Jeff

    1999-01-01

    Presents an analysis of an astrophysics institute designed for high school students. Investigates how students respond cognitively in an active science-learning environment in which they serve as apprentices to university astrophysics professors. (Author/CCM)

  17. Using geophysics to characterize levee stability

    NASA Astrophysics Data System (ADS)

    Dalton, Laura M.

    Shallow slough slides have occurred along the river side slope of Mississippi River Levees for over sixty years. Shallow slough slides also occur along smaller levees that protect tributaries of the Mississippi River. This investigation takes place along a section of the Coldwater River Levee, a tributary levee of the Mississippi River. Field observation, soil samples, and geophysical data were collected at two field sites located on the border of Tate and Tunica County, MS. The first site consists of a developed shallow slough slide that had occurred that has not yet been repaired and the second site is a potential slide area. Electromagnetic induction and electrical resistivity tomography were the geophysical methods used to define subsurface conditions that make a levee vulnerable to failure. These electrical methods are sensitive to the electrical conductivity of the soil and therefore depend upon: soil moisture, clay content, pore size distribution as well as larger scale structures at depth such as cracks and fissures. These same physical properties of the soil are also important to assessing the vulnerability of a levee to slough slides. Soil tests and field observations were also implemented in this investigation to describe and classify the soil composition of the levee material. The problem of slough slide occurrence can potentially be reduced if vulnerabilities are located with the help of geophysical techniques.

  18. Geophysical mapping of solution and collapse sinkholes

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg

    2014-12-01

    Karst rocks such as limestone, dolomite, anhydrite, gypsum, or salt can be dissolved physically by water or chemically by water enriched with carbon dioxide. The dissolution is driven by water flowing through the karst aquifer and either occurs along fractures and bedding partings in telogenetic rocks, or within the primary interconnected pore space in eogenetic rocks. The enlargement of either fractures or pores by dissolution creates a large secondary porosity typical of soluble rocks, which is often very heterogenously distributed and results in preferential flow paths in the sub-surface, with cavities as large-scale end members of the sub-surface voids. Once the sub-surface voids enlarged by dissolution grow to a certain size, the overburden rock can become unstable and voids and caves can collapse. Depending on the type of overburden, the collapse initiated at depth may propagate towards the surface and finally results at the surface as collapse sinkholes and tiangkengs on the very large scale. We present results from geophysical surveys over existing karst structures based on gravimetric, electrical, and geomagnetical methods. We have chosen two types of sinkholes, solution and collapse sinkholes, to capture and compare the geophysical signals resulting from these karst structures. We compare and discuss our geophysical survey results with simplified theoretical models describing the evolution of the karst structure, and we derive three-dimensional structural models of the current situation for the different locations with our numerical tool PREDICTOR.

  19. The Astrophysics Major at the University of California, Berkeley

    NASA Astrophysics Data System (ADS)

    Arons, J.; Heiles, C.

    2001-12-01

    The Astrophysics major offered by the Berkeley Astronomy Department has been redesigned to reflect broad educational goals. Students preparing for graduate school study mostly Physics and Mathematics, leavened with four semesters of astrophysics at the sophomore and senior level. These courses make heavy use of their concurrent Physics and Math. Astrophysics and Physics majors differ in the astrophysics courses replacing other electives which a Physics major might choose. The major's redesign also opened the door to students who wish to pursue a major which gives them broad technical training without having graduate school as a goal. Many such students follow the same track as those pursuing the graduate school option; others take courses specifically designed for people with alternate careers in mind. The major change has been a laboratory requirement for all Astrophysics majors, in either track. We now have advanced undergraduate laboratories: optical, radio, and near infrared; details are on our web page. These share the common thread of development of deep capabilities in data gathering, analysis, and presentation. Students achieve expertise in these areas because the labs include the complete range of activities normally encountered in observational or experimental research. Students use laboratory equipment to measure the fundamental parameters of devices and systems, make astronomical observations with those systems, write software in UNIX and IDL to control equipment and analyze the results, and write formal lab reports in LATEX. We avoid ``black box'' or ``cookbook'' procedures . The students leave the course having gained experience and knowledge, and a ``feel'' for how to proceed when faced with sometimes recalcitrant equipment and imperfect data. A by product of the training has been an increase in student involvement in undergraduate research projects. These innovations have led to a major that has doubled in size and, in a quite unanticipated

  20. Final Report: SciDAC Computational Astrophysics Consortium (at Princeton University)

    SciTech Connect

    Burrows, Adam

    2012-12-03

    Supernova explosions are the central events in astrophysics. They are the major agencies of change in the interstellar medium, driving star formation and the evolution of galaxies. Their gas remnants are the birthplaces of the cosmic rays. Such is their brightness that they can be used as standard candles to measure the size and geometry of the universe and their investigation draws on particle and nuclear physics, radiative transfer, kinetic theory, gravitational physics, thermodynamics, and the numerical arts. Hence, supernovae are unrivaled astrophysical laboratories. We will develop new state-of-the-art multi-dimensional radiation hydrodynamic codes to address this and other related astrophysical phenomena.

  1. Jesuit Geophysical Observatories

    NASA Astrophysics Data System (ADS)

    Udias, Agustin; Stauder, William

    Jesuits have had ah interest in observing and explaining geophysical phenomena since this religious order, the Society of Jesus, was founded by Ignatius of Loyola in 1540. Three principal factors contributed to this interest: their educational work in colleges and universities, their missionary endeavors to remote lands where they observed interesting and often as yet undocumented natural phenomena, and a network of communication that brought research of other Jesuits readily to their awareness.One of the first and most important Jesuit colleges was the Roman College (today the Gregorian University) founded in 1551 in Rome, which served as a model for many other universities throughout the world. By 1572, Christopher Clavius (1537-1612), professor of mathematics at the Roman College, had already initiated an important tradition of Jesuit research by emphasizing applied mathematics and insisting on the need of serious study of mathematics in the program of studies in the humanities. In 1547 he directed a publication of Euclid's work with commentaries, and published several treatises on mathematics, including Arithmetica Practica [1585], Gnomonicae [1581], and Geometrica Practica [1606]. Clavius was also a Copernican and supported his friend Galileo when he announced the discovery of the satellites of Jupiter.

  2. A ``model`` geophysics program

    SciTech Connect

    Nyquist, J.E.

    1994-03-01

    In 1993, I tested a radio-controlled airplane designed by Jim Walker of Brigham Young University for low-elevation aerial photography. Model-air photography retains most of the advantages of standard aerial photography --- the photographs can be used to detect lineaments, to map roads and buildings, and to construct stereo pairs to measure topography --- and it is far less expensive. Proven applications on the Oak Ridge Reservation include: updating older aerial records to document new construction; using repeated overflights of the same area to capture seasonal changes in vegetation and the effects of major storms; and detecting waste trench boundaries from the color and character of the overlying grass. Aerial photography is only one of many possible applications of radio-controlled aircraft. Currently, I am funded by the Department of Energy`s Office of Technology Development to review the state of the art in microavionics, both military and civilian, to determine ways this emerging technology can be used for environmental site characterization. Being particularly interested in geophysical applications, I am also collaborating with electrical engineers at Oak Ridge National Laboratory to design a model plane that will carry a 3-component flux-gate magnetometer and a global positioning system, which I hope to test in the spring of 1994.

  3. ‘Firewall’ phenomenology with astrophysical neutrinos

    NASA Astrophysics Data System (ADS)

    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.

  4. Observational Manifestation of Chaos in Astrophysical Objects

    NASA Astrophysics Data System (ADS)

    Fridman, A.; Marov, M.; Miller, R.

    2002-12-01

    This book addresses a broad range of problems related to observed manifestations of chaotic motions in galactic and stellar objects, by invoking basic theory, numerical modeling, and observational evidence. For the first time, methods of stochastic dynamics are applied to actually observed astronomical objects, e.g. the gaseous disc of the spiral galaxy NGC 3631. In the latter case, the existence of chaotic trajectories in the boundary of giant vortices was recently found by the calculation of the Lyapunov characteristic number of these trajectories. The reader will find research results on the peculiarities of chaotic system behaviour; a study of the integrals of motion in self-consistent systems; numerical modeling results of the evolution process of disk systems involving resonance excitation of the density waves in spiral galaxies; a review of specific formations in stars and high-energy sources demonstrating their stochastic nature; a discussion of the peculiarities of the precessional motion of the accretion disk and relativistic jets in the double system SS 433; etc. This book stands out as the first one that deals with the problem of chaos in real astrophysical objects. It is intended for graduate and post-graduate students in the fields of non-linear dynamics, astrophysics, planetary and space physics; specifically for those dealing with computer modeling of the relevant processes. Link: http://www.wkap.nl/prod/b/1-4020-0935-6

  5. NASA's Laboratory Astrophysics Workshop: Opening Remarks

    NASA Technical Reports Server (NTRS)

    Hasan, Hashima

    2002-01-01

    The Astronomy and Physics Division at NASA Headquarters has an active and vibrant program in Laboratory Astrophysics. The objective of the program is to provide the spectroscopic data required by observers to analyze data from NASA space astronomy missions. The program also supports theoretical investigations to provide those spectroscopic parameters that cannot be obtained in the laboratory; simulate space environment to understand formation of certain molecules, dust grains and ices; and production of critically compiled databases of spectroscopic parameters. NASA annually solicits proposals, and utilizes the peer review process to select meritorious investigations for funding. As the mission of NASA evolves, new missions are launched, and old ones are terminated, the Laboratory Astrophysics program needs to evolve accordingly. Consequently, it is advantageous for NASA and the astronomical community to periodically conduct a dialog to assess the status of the program. This Workshop provides a forum for producers and users of laboratory data to get together and understand each others needs and limitations. A multi-wavelength approach enables a cross fertilization of ideas across wavelength bands.

  6. Investigating High Field Gravity using Astrophysical Techniques

    SciTech Connect

    Bloom, Elliott D.; /SLAC

    2008-02-01

    The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques. As the subject matter is vast, compromises are necessary in order to convey the central ideas to the reader. Many general references are included for those who want to learn more. The paragraphs below elaborate on the structure of these lectures. I hope this discussion will clarify my motivation and make the lectures easier to follow. The lectures begin with a brief review of more theoretical ideas. First, elements of general relativity are reviewed, concentrating on those aspects that are needed to understand compact stellar objects (white dwarf stars, neutron stars, and black holes). I then review the equations of state of these objects, concentrating on the simplest standard models from astrophysics. After these mathematical preliminaries, Sec. 2(c) discusses 'The End State of Stars'. Most of this section also uses the simplest standard models. However, as these lectures are for particle physicists, I also discuss some of the more recent approaches to the equation of state of very dense compact objects. These particle-physics-motivated equations of state can dramatically change how we view the formation of black holes. Section 3 focuses on the properties of the objects that we want to characterize and measure. X-ray binary systems and Active Galactic Nuclei (AGN) are stressed because the lectures center on understanding very dense stellar objects, black hole candidates (BHCs), and their accompanying high gravitational fields. The use of x-ray timing and gamma-ray experiments is also introduced in this section. Sections 4 and 5 review information from x-ray and gamma-ray experiments. These sections also discuss the current state of the art in x-ray and gamma-ray satellite experiments and

  7. Astrophysics of galaxy clusters

    NASA Astrophysics Data System (ADS)

    Ettori, Stefano

    2016-07-01

    As the nodes of the cosmic web, clusters of galaxies trace the large-scale distribution of matter in the Universe. They are thus privileged sites in which to investigate the complex physics of structure formation. However, the complete story of how these structures grow, and how they dissipate the gravitational and non-thermal components of their energy budget over cosmic time, is still beyond our grasp. Most of the baryons gravitationally bound to the cluster's halo is in the form of a diffuse, hot, metal-enriched plasma that radiates primarily in the X-ray band. X-ray observations of the evolving cluster population provide a unique opportunity to address such fundamental open questions as: How do hot diffuse baryons accrete and dynamically evolve in dark matter potentials? How and when was the energy that we observe in the ICM generated and distributed? Where and when are heavy elements produced and how are they circulated? We will present the ongoing activities to define the strategy on how an X-ray observatory with large collecting area and an unprecedented combination of high spectral and angular resolution, such as Athena, can address these questions.

  8. Frontiers in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Kajino, T.

    2016-07-01

    The synthesis of nuclei in diverse cosmic scenarios is reviewed, with a summary of the basic concepts involved before a discussion of the current status in each case is made. We review the physics of the early universe, the proton to neutron ratio influence in the observed helium abundance, reaction networks, the formation of elements up to beryllium, the inhomogeneous Big Bang model, and the Big Bang nucleosynthesis constraints on cosmological models. Attention is paid to element production in stars, together with the details of the pp chain, the pp reaction, 3He formation and destruction, electron capture on 7Be, the importance of 8B formation and its relation to solar neutrinos, and neutrino oscillations. Nucleosynthesis in massive stars is also reviewed, with focus on the CNO cycle and its hot companion cycle, the rp-process, triple- α capture, and red giants and AGB stars. The stellar burning of carbon, neon, oxygen, and silicon is presented in a separate section, as well as the slow and rapid nucleon capture processes and the importance of medium modifications due to electrons also for pycnonuclear reactions. The nucleosynthesis in cataclysmic events such as in novae, X-ray bursters and in core-collapse supernovae, the role of neutrinos, and the supernova radioactivity and light-curve is further discussed, as well as the structure of neutron stars and its equation of state. A brief review of the element composition found in cosmic rays is made in the end.

  9. Inversion Algorithms for Geophysical Problems

    DTIC Science & Technology

    1987-12-16

    ktdud* Sccumy Oass/Kjoon) Inversion Algorithms for Geophysical Problems (U) 12. PERSONAL AUTHOR(S) Lanzano, Paolo 13 «. TYPE OF REPORT Final 13b...spectral density. 20. DISTRIBUTION/AVAILABILITY OF ABSTRACT 13 UNCLASSIFIED/UNLIMITED D SAME AS RPT n OTIC USERS 22a. NAME OF RESPONSIBLE...Research Laboratory ’^^ SSZ ’.Washington. DC 20375-5000 NRLrMemorandum Report-6138 Inversion Algorithms for Geophysical Problems p. LANZANO Space

  10. Marine Geophysics: a Navy Symposium

    DTIC Science & Technology

    1987-09-01

    post-docs are now the current leaders in marine geology and geophysics, not only in the United States but also in Britain, France, and Australia ...to make it fun both for themselves and for others was the keystone of the success of the marine geology and geophysics program at Scripps. They, with...G. G. Shor, Jr., R. W. Raitt, and M. Henry. 1977. Seismic refraction and reflection studies of crustal structure of the eastern Sunda and western

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Takabe, Hideaki

    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 (1D & 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.

  13. Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

    SciTech Connect

    Koppenjan, S,; Martinez, M.

    1994-06-01

    The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE`s Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ``chirped`` FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.

  14. Resources for History of Geophysics at AIP

    NASA Astrophysics Data System (ADS)

    Good, G. A.

    2012-12-01

    The history programs of the American Institute of Physics -- the Center for History of Physics and the Niels Bohr Library & Archives -- maintain a wide variety of research resources for the history of physics generally, and for the history of geophysics in particular. AIP has over 20,000 photographs online, nearly 1000 oral history interview transcripts, and much more. The International Catalog of Sources provides an online union catalog of manuscript collections held worldwide. An important collection of IUGG records is available onsite, as also is the recently accessioned collection of AGU papers. As the 2019 centenary of AGU approaches, these resources will be of interest to both AGU members and historians of science.;

  15. Building a visionary astrophysics program from the ground up

    NASA Astrophysics Data System (ADS)

    Mathews, Geoffrey S.; Barnes, Joshua Edward; Coleman, Paul; Gal, Roy R.; Meech, Karen J.; Mendez, Roberto Hugo; Nassir, Michael A.; Sanders, David B.

    2015-08-01

    The University of Hawaii’s Institute for Astronomy is in the process of implementing a new Bachelor of Science in Astrophysics at UH Manoa. This requires a significant adjustment in the role of the IfA, which has long been at the forefront of modern astronomy in Hawaii and is now broadening its educational mission. The IfA’s history of excellence in research and access to observational resources are expected to draw students from around the nation and the world. These factors have inspired our programmatic focus culminating in a senior year research experience. We expect that the program will produce many undergraduate astrophysics majors, making it an ideal testbed to apply modern theories of learning to the teaching of astrophysics. We have explicitly designed the major around three pillars: physical theory, the application of physics to astrophysical phenomena, and the development of core observational astronomy skills. We describe our cooperative approach to developing a program-level curriculum map of key concepts and skills, as well as descriptors of student success throughout the program. These are central tools for course design, program assessment, and professional development.

  16. The generation, destination, and astrophysical applications of magnetohydrodynamic turbulence

    NASA Astrophysics Data System (ADS)

    Xu, Siyao; Lazarian, Alex; Zhang, Bing

    2017-01-01

    The ubiquitous turbulence in the interstellar medium (ISM) participates in astrophysical processes over a huge dynamic range of scales. Understanding the turbulence properties in the multiphase, magnetized, partially ionized, and compressible ISM is the fundamental step prior to the studies of the ISM physics and other fields of astrophysics. I feel that a triad of analytical, numerical and observational efforts provides a winning combination to understand this complex system and solve long-standing puzzles. I have intensively studied the fundamental physics of magnetohydrodynamic (MHD) turbulence, and focused on two primary domains, dynamo and dissipation, which concern the origin of strong magnetic fields and the destination of turbulence, respectively. I further applied my theoretical studies in interpreting numerical results and observational data in various astrophysical contexts. The advanced analyses of MHD turbulence enable me to address a number of challenging astrophysical problems, e.g. the importance of magnetic fields for star formation in the early and present-day universe, new methods of measuring magnetic fields, the density distribution in the Galaxy and the host galaxy of a fast radio burst, the diffusion and acceleration of cosmic rays in partially ionized ISM phases.

  17. Laboratory Astrophysics White Paper: Summary of Laboratory Astrophysics Needs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The NASA Laboratory Astrophysics Workshop (NASA LAW) met at NASA Ames Research Center from 1-3 May 2002 to assess the role that laboratory astrophysics plays in the optimization of NASA missions, both at the science conception level and at the science return level. Space missions provide understanding of fundamental questions regarding the origin and evolution of galaxies, stars, and planetary systems. In all of these areas the interpretation of results from NASA's space missions relies crucially upon data obtained from the laboratory. We stress that Laboratory Astrophysics is important not only in the interpretation of data, but also in the design and planning of future missions. We recognize a symbiosis between missions to explore the universe and the underlying basic data needed to interpret the data from those missions. In the following we provide a summary of the consensus results from our Workshop, starting with general programmatic findings and followed by a list of more specific scientific areas that need attention. We stress that this is a 'living document' and that these lists are subject to change as new missions or new areas of research rise to the fore.

  18. ``Recycling'' Geophysics: Monitoring and Isotopic Analysis of Engineered Biological Systems

    NASA Astrophysics Data System (ADS)

    Doherty, R.; Singh, K. P.; Ogle, N.; Ntarlagiannis, D.

    2010-12-01

    The emerging sub discipline of biogeophysics has provoked debate on the mechanisms of microbial processes that may contribute to geophysical signatures. At field scales geophysical signatures are often non unique due to the many parameters (physical, chemical, and biological) that are involved. It may be easier to apply geophysical techniques such as electrodic potential (EP), self potential (SP) and induced polarization (IP) to engineered biological systems where there is a degree of control over the design of the physical and chemical domain. Here we present results of a column experiment that was designed to anaerobically biodegrade dissolved organic matter in landfill leachate. The column utilises a recycled porous media (concrete) to help sequester organic carbon. Electrodic potential, self potential and induced polarisation are used in conjunction with chemical and isotopic techniques to monitor the effectiveness of this approach. Preliminary carbon and oxygen isotopic analysis on concrete from the column in contact with leachate show isotopic enrichment suggesting abiotic precipitation of carbonates.

  19. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Zuber, Maria

    2005-01-01

    The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.

  20. The impact of recent advances in laboratory astrophysics on our understanding of the cosmos.

    PubMed

    Savin, D W; Brickhouse, N S; Cowan, J J; Drake, R P; Federman, S R; Ferland, G J; Frank, A; Gudipati, M S; Haxton, W C; Herbst, E; Profumo, S; Salama, F; Ziurys, L M; Zweibel, E G

    2012-03-01

    An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools used to probe such phenomena-the radiation and particle spectra we observe-have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.

  1. A laser application to nuclear astrophysics

    SciTech Connect

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B.; Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Bonasera, A.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2014-05-09

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  2. Astrophysics for Older adults in Chicago.

    NASA Astrophysics Data System (ADS)

    Grin, Daniel; Landsberg, Randall H.; Flude, Karen

    2017-01-01

    Gerontology research continues to show that the adage "Use it or Lose it" is a clinical fact when it comes to cognitive engagement post-retirement. Here, I'll discuss a new program developed at the Kavli Institute for Cosmological Physics, bringing classes on astrophysics to older adults throughout the city, at retirement homes, at senior center, and at public libraries, bookended by an engaging trip to the Adler Planetarium. In my presentation, I'll present the gerontological and policy motivations for this program, the presenter training techniques, our partner collaboration strategy, and the results of our effort, which engaged hundreds of older adults throughout Chicago from a variety of socioeconomic strata.

  3. Astrophysical fractals - An overview and prospects

    NASA Technical Reports Server (NTRS)

    Perdang, J.

    1990-01-01

    Different astrophysical circumstances under which fractal structures have been identified so far, or are likely to be identified in the future, are reviewed. The observed fractals can be classified into 2 main groups: (1) fractal configurations in space-time, materializing as fractals defined over the time axis at a given position in space, or over the physical configuration space at a fixed instant in time; and (2) fractals in parameter spaces. The theoretical interpretation of the origin of the spatial fractal geometry of the most conspicuous 'irregular' astronomical bodies is still wanting in the context of standard continuum models. In contrast, the less conventional discrete models (cellular automata) naturally produce such spatially fractal structures.

  4. Fundamental Interactions, Nuclear Masses, Astrophysics, and QCD

    SciTech Connect

    Gagliardi, C. A.

    2008-01-24

    During his long and varied career, Robert Tribble has made important contributions in many areas of nuclear physics. He has set new limits on the existence of second-class currents, lepton-flavor violation, and right-handed interactions. He optimized the use of the ({sup 4}He,{sup 8}He) reaction to determine nuclear masses and study charge-dependent effects in nuclei. He has developed a new indirect procedure to determine astrophysical reaction rates and applied it to study important nuclear reactions that occur in our sun, in massive stars, and in novae. He has explored anti-quark distributions in nucleons and nuclei, and the polarization of gluons in the nucleon. A brief overview of Bob Tribble's many accomplishments is presented.

  5. Simulations of radiative astrophysical jets

    NASA Astrophysics Data System (ADS)

    Estabrook, Kent; Remington, Bruce; Farley, Dave; Glendinning, Gail; Suter, L. J.; Harte, J. H.; Zimmerman, G. B.; London, R. A.; Stone, James M.; Wood-Vasey, Michael; Drake, R. Paul

    1998-11-01

    Astrophysical jets are poorly understood, but we know that radiation is usually important. Using the LLNL Nova laser facility, we can accelerate jets to velocities of order 10^7cm/sec with either direct laser illumination or radiation drive in either hemispheres or cones. We present 2-D LASNEX simulations of such experiments with medium and high z materials with and without radiation loses[1]. Related papers by Bruce Remington, Dave Farley, James Stone, Gail Glendinning, Paul Drake and Jave Kane are at this meeting. [1] J.M.Stone, J.J.Xu, P.E.Hardee, Astrophysical J. 483,136(1997). Auspices U.S.D.O.E. by LLNL Contract W-7405-ENG-48

  6. Geophysics: The Earth in Space. A Guide for High School Students.

    ERIC Educational Resources Information Center

    American Geophysical Union, Washington, DC.

    Geophysics is the application of physics, chemistry, and mathematics to the problems and processes of the earth, from its innermost core to its outermost environs in space. Fields within geophysics include the atmospheric sciences; geodesy; geomagnetism and paleomagnetism; hydrology; oceanography; planetology; seismology; solar-planetary…

  7. Geophysics of Small Planetary Bodies

    NASA Technical Reports Server (NTRS)

    Asphaug, Erik I.

    1998-01-01

    As a SETI Institute PI from 1996-1998, Erik Asphaug studied impact and tidal physics and other geophysical processes associated with small (low-gravity) planetary bodies. This work included: a numerical impact simulation linking basaltic achondrite meteorites to asteroid 4 Vesta (Asphaug 1997), which laid the groundwork for an ongoing study of Martian meteorite ejection; cratering and catastrophic evolution of small bodies (with implications for their internal structure; Asphaug et al. 1996); genesis of grooved and degraded terrains in response to impact; maturation of regolith (Asphaug et al. 1997a); and the variation of crater outcome with impact angle, speed, and target structure. Research of impacts into porous, layered and prefractured targets (Asphaug et al. 1997b, 1998a) showed how shape, rheology and structure dramatically affects sizes and velocities of ejecta, and the survivability and impact-modification of comets and asteroids (Asphaug et al. 1998a). As an affiliate of the Galileo SSI Team, the PI studied problems related to cratering, tectonics, and regolith evolution, including an estimate of the impactor flux around Jupiter and the effect of impact on local and regional tectonics (Asphaug et al. 1998b). Other research included tidal breakup modeling (Asphaug and Benz 1996; Schenk et al. 1996), which is leading to a general understanding of the role of tides in planetesimal evolution. As a Guest Computational Investigator for NASA's BPCC/ESS supercomputer testbed, helped graft SPH3D onto an existing tree code tuned for the massively parallel Cray T3E (Olson and Asphaug, in preparation), obtaining a factor xIO00 speedup in code execution time (on 512 cpus). Runs which once took months are now completed in hours.

  8. Novel laboratory simulations of astrophysical jets

    NASA Astrophysics Data System (ADS)

    Brady, Parrish Clawson

    This thesis was motivated by the promise that some physical aspects of astrophysical jets and collimation processes can be scaled to laboratory parameters through hydrodynamic scaling laws. The simulation of astrophysical jet phenomena with laser-produced plasmas was attractive because the laser- target interaction can inject energetic, repeatable plasma into an external environment. Novel laboratory simulations of astrophysical jets involved constructing and using the YOGA laser, giving a 1064 nm, 8 ns pulse laser with energies up to 3.7 + 0.2 J . Laser-produced plasmas were characterized using Schlieren, interferometry and ICCD photography for their use in simulating jet and magnetosphere physics. The evolution of the laser-produced plasma in various conditions was compared with self-similar solutions and HYADES computer simulations. Millimeter-scale magnetized collimated outflows were produced by a centimeter scale cylindrically symmetric electrode configuration triggered by a laser-produced plasma. A cavity with a flared nozzle surrounded the center electrode and the electrode ablation created supersonic uncollimated flows. This flow became collimated when the center electrode changed from an anodeto a cathode. The plasma jets were in axially directed permanent magnetic fields with strengths up to 5000 Gauss. The collimated magnetized jets were 0.1-0. 3 cm wide, up to 2.0 cm long, and had velocities of ~4.0 × 10 6 cm/s. The dynamics of the evolution of the jet were compared qualitatively and quantitatively with fluxtube simulations from Bellan's formulation [6] giving a calculated estimate of ~2.6 × 10 6 cm/s for jet evolution velocity and evidence for jet rotation. The density measured with interferometry was 1.9 ± 0.2 × 10 17 cm -3 compared with 2.1 × 10 16 cm -3 calculated with Bellan's pressure balance formulation. Kinks in the jet column were produced consistent with the Kruskal-Shafranov condition which allowed stable and symmetric jets to form with

  9. New geophysical models related to heat sources in the geysers-clear lake region, California

    USGS Publications Warehouse

    Stanley, W.D.; Blakely, R.J.; ,

    1993-01-01

    We present an updated view of the geological and geophysical complexities of the upper crust in The Geysers-Clear Lake region in order to provide additional information regarding local structures and possible heat sources. New models and ideal-body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies may be significantly affected by rock-property and physical-state variations in the upper 7 km, and not just to 'magma' at greater depths. We developed the new geophysical models in order to better understand constraints on the location of magma bodies.

  10. Activation Experiments for Nuclear Astrophysics

    SciTech Connect

    Sonnabend, K.; Mueller, S.; Pietralla, N.; Savran, D.; Schnorrenberger, L.; Hasper, J.; Zilges, A.

    2009-01-28

    The study of ({gamma},n) reactions can be used to constrain the theoretical predictions of the neutron capture cross sections of short-lived branching points in the s process. The usability of the activation technique to study these ({gamma},n) reactions is discussed as one example of an activation experiment in nuclear astrophysics. Two photon sources using bremsstrahlung and laser-Compton backscattered photons where such experiments were carried out are compared.

  11. National Centre for Radio Astrophysics

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    India's National Centre for Radio Astrophysics (NCRA), located on the Pune University Campus, is part of the TATA INSTITUTE OF FUNDAMENTAL RESEARCH. At Khodad, 80 km from Pune, NCRA has set up the Giant Metrewave Radio Telescope (GMRT), the world's largest telescope operating at meter wavelengths. GMRT consists of 30 fully steerable dishes of 45 m diameter, spread over a 25 km area. Another meter...

  12. Rounding Up the Astrophysical Weeds

    NASA Astrophysics Data System (ADS)

    McMillan, James P.

    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.

  13. Astrophysics with Microarcsecond Accuracy Astrometry

    NASA Technical Reports Server (NTRS)

    Unwin, Stephen C.

    2008-01-01

    Space-based astrometry promises to provide a powerful new tool for astrophysics. At a precision level of a few microarcsonds, a wide range of phenomena are opened up for study. In this paper we discuss the capabilities of the SIM Lite mission, the first space-based long-baseline optical interferometer, which will deliver parallaxes to 4 microarcsec. A companion paper in this volume will cover the development and operation of this instrument. At the level that SIM Lite will reach, better than 1 microarcsec in a single measurement, planets as small as one Earth can be detected around many dozen of the nearest stars. Not only can planet masses be definitely measured, but also the full orbital parameters determined, allowing study of system stability in multiple planet systems. This capability to survey our nearby stellar neighbors for terrestrial planets will be a unique contribution to our understanding of the local universe. SIM Lite will be able to tackle a wide range of interesting problems in stellar and Galactic astrophysics. By tracing the motions of stars in dwarf spheroidal galaxies orbiting our Milky Way, SIM Lite will probe the shape of the galactic potential history of the formation of the galaxy, and the nature of dark matter. Because it is flexibly scheduled, the instrument can dwell on faint targets, maintaining its full accuracy on objects as faint as V=19. This paper is a brief survey of the diverse problems in modern astrophysics that SIM Lite will be able to address.

  14. Cluster analysis applied to multiparameter geophysical dataset

    NASA Astrophysics Data System (ADS)

    Di Giuseppe, M. G.; Troiano, A.; Troise, C.; De Natale, G.

    2012-04-01

    Multi-parameter acquisition is a common geophysical field practice nowadays. Regularly seismic velocity and attenuation, gravity and electromagnetic dataset are acquired in a certain area, to obtain a complete characterization of the some investigate feature of the subsoil. Such a richness of information is often underestimated, although an integration of the analysis could provide a notable improving in the imaging of the investigated structures, mostly because the handling of distinct parameters and their joint inversion still presents several and severe problems. Post-inversion statistical techniques represent a promising approach to these questions, providing a quick, simple and elegant way to obtain this advantageous but complex integration. We present an approach based on the partition of the analyzed multi parameter dataset in a number of different classes, identified as localized regions of high correlation. These classes, or 'Cluster', are structured in such a way that the observations pertaining to a certain group are more similar to each other than the observations belonging to a different one, according to an optimal logical criterion. Regions of the subsoil sharing the same physical characteristic are so identified, without a-priori or empirical relationship linking the distinct measured parameters. The retrieved imaging results highly affordable in a statistical sense, specifically due to this lack of external hypothesis that are, instead, indispensable in a full joint inversion, were works, as matter of fact, just a real constrain for the inversion process, not seldom of relative consistence. We apply our procedure to a certain number of experimental dataset, related to several structures at very different scales presents in the Campanian district (southern Italy). These structures goes from the shallows evidence of the active fault zone originating the M 7.9 Irpinia earthquake to the main feature characterizing the Campi Flegrei Caldera and the Mt

  15. How can laboratory plasma experiments contribute to space and &astrophysics?

    NASA Astrophysics Data System (ADS)

    Yamada, M.

    Plasma physics plays key role in a wide range of phenomena in the universe, from laboratory plasmas to the magnetosphere, the solar corona, and to the tenuous interstellar and intergalactic gas. Despite the huge difference in physical scales, there are striking similarities in plasma behavior of laboratory and space plasmas. Similar plasma physics problems have been investigated independently by both laboratory plasma physicists and astrophysicists. Since 1991, cross fertilization has been increased among laboratory plasma physicists and space physicists through meeting such as IPELS [Interrelationship between Plasma Experiments in the Laboratory and Space] meeting. The advances in laboratory plasma physics, along with the recent surge of astronomical data from satellites, make this moment ripe for research collaboration to further advance plasma physics and to obtain new understanding of key space and astrophysical phenomena. The recent NRC review of astronomy and astrophysics notes the benefit that can accrue from stronger connection to plasma physics. The present talk discusses how laboratory plasma studies can contribute to the fundamental understandings of the space and astrophysical phenomena by covering common key physics topics such as magnetic reconnection, dynamos, angular momentum transport, ion heating, and magnetic self-organization. In particular, it has recently been recognized that "physics -issue- dedicated" laboratory experiments can contribute significantly to the understanding of the fundamental physics for space-astrophysical phenomena since they can create fundamental physics processes in controlled manner and provide well-correlated plasma parameters at multiple plasma locations simultaneously. Such dedicated experiments not only can bring about better understanding of the fundamental physics processes but also can lead to findings of new physics principles as well as new ideas for fusion plasma confinement. Several dedicated experiments have

  16. Physics News in 1983.

    ERIC Educational Resources Information Center

    Schewe, Phillip F., Ed.

    Information is provided on some of the interesting and newsworthy developments in physics and its related fields during 1983. Areas considered include: (1) acoustics; (2) astrophysics; (3) condensed matter physics; (4) crystallography; (5) physics education; (6) electron and atomic physics; (7) elementary particle physics; (8) fluid dynamics; (9)…

  17. Laboratory Astrophysics as Key to Understanding the Universe

    NASA Astrophysics Data System (ADS)

    van Dishoeck, Ewine F.

    2012-05-01

    Modern astrophysics is blessed with an increasing amount of high quality observational data on astronomical sources, ranging from our own solar system to the edge of the Universe and from the lowest temperature clouds to the highest energy cosmic rays. Spectra containing thousands of features of atoms, molecules, ice and dust are routinely obtained for stars, planets, comets, the ISM andstar-forming regions, and in the near future even for the most distant galaxies. Realistic models of exo-planetary atmospheres require information on billions of lines. Theories of jets from young stars benefit from plasma experiments to benchmark them. Stellar evolution theories and cosmology rely heavily on accurate rates for nuclear fusion reactions. The first stars could not have formed without the simplest chemical reactions taking place in primordial clouds. Particle physics is at the heart of finding candidates for the mysterious dark matter. There is no doubt that laboratory astrophysics, which includes theoretical calculations, remains at the foundation of the interpretation of observations and truly 'makes astronomy tick'. In this talk, several recent developments in determining these fundamental data will be presented which have resulted in significant advances in our understanding of astrophysical environments. Often, a comparatively minor investment in basic studies can greatly enhance the scientific return from missions. Examples will be taken from each of the 6 themes of the new Laboratory Astrophysics dvision of the AAS (www.aas.org/labastro/lawg_charter.php): atomic, molecular, solid matter, plasma, nuclear, and particle physics. Special attention will be given to recent results from infrared and millimeter facilities, including Herschel and ALMA, which reveal rich spectra of water and organic molecules in star- and planet forming zones. Their interpretation is greatly added by the application of ultra-high vacuum surface science techniques to astrophysical problems.

  18. SAGE celebrates 25 years of learning geophysics by doing geophysics

    USGS Publications Warehouse

    Jiracek, G.R.; Baldridge, W.S.; Sussman, A.J.; Biehler, S.; Braile, L.W.; Ferguson, J.F.; Gilpin, B.E.; McPhee, D.K.; Pellerin, L.

    2008-01-01

    The increasing world demand and record-high costs for energy and mineral resources, along with the attendant environmental and climate concerns, have escalated the need for trained geophysicists to unprecedented levels. This is not only a national need; it's a critical global need. As Earth scientists and educators we must seriously ask if our geophysics pipeline can adequately address this crisis. One program that has helped to answer this question in the affirmative for 25 years is SAGE (Summer of Applied Geophysical Experience). SAGE continues to develop with new faculty, new collaborations, and additional ways to support student participation during and after SAGE. ?? 2008 Society of Exploration Geophysicists.

  19. High Energy Astrophysics and Cosmology from Space

    NASA Astrophysics Data System (ADS)

    Hornschemeier, Ann

    2014-03-01

    While much can be learned from physics experiments on and astronomical observations from the ground, certain questions require space-based investigations. Sometimes the scale of the measurement, such as the baseline of approximately 106 km necessary for the observation of gravitational waves in the frequency range expected for high-redshift supermassive black hole mergers, causes us to leave behind the limitations of the earth. From space we measure the X-ray emission from the final stages of accretion onto black holes and critical energy ranges of cosmic rays and gamma ray photons resulting from particle acceleration in e.g., star forming environments, that otherwise we could not measure due to the atmosphere. Space-borne experiments may also measure all of the cosmological information available in the polarization of the cosmic microwave background to probe the physical conditions that caused the process of inflation in the early universe, moments after the big bang. This presentation will cover the NASA high energy astrophysics and cosmology science portfolio, embodied in its Physics of the Cosmos program, including updates on technology development and programmatic matters.

  20. Object Storage for Geophysical Data

    NASA Astrophysics Data System (ADS)

    Habermann, T.; Readey, J.

    2015-12-01

    Object storage systems (such as Amazon S3 or Ceph) have been shown to be cost-effective and highly scalable for data repositories in the Petabyte range and larger. However traditionally data storage used for geophysical software systems has centered on file-based systems and libraries such as NetCDF and HDF5. In this session we'll discuss the advantages and challenges of moving to an object store-based model for geophysical data. We'll review a proposed model for a geophysical data service that provides an API-compatible library for traditional NetCDF and HDF5 applications while providing high scalability and performance. One further advantage of this approach is that any dataset or dataset selection can be referenced as a URI. By using versioning, the data the URI references can be guaranteed to be unmodified, thus enabling reproducibility of referenced data.

  1. Continental crust: a geophysical approach

    SciTech Connect

    Meissner, R.

    1986-01-01

    This book develops an integrated and balanced picture of present knowledge of the continental crust. Crust and lithosphere are first defined, and the formation of crusts as a general planetary phenomenon is described. The background and methods of geophysical studies of the earth's crust and the collection of related geophysical parameters are examined. Creep and friction experiments and the various methods of radiometric age dating are addressed, and geophysical and geological investigations of the crustal structure in various age provinces of the continents are studied. Specific tectonic structures such as rifts, continental margins, and geothermal areas are discussed. Finally, an attempt is made to give a comprehensive view of the evolution of the continental crust and to collect and develop arguments for crustal accretion and recycling. 647 references.

  2. Theoretical nuclear structure and astrophysics. Progress report for 1996

    SciTech Connect

    Guidry, M.W.; Nazarewicz, W.; Strayer, M.R.

    1996-12-31

    This research effort is directed toward theoretical support and guidance for the fields of radioactive ion beam physics, gamma ray spectroscopy, computational and nuclear astrophysics, and the interface between these disciplines. The authors report substantial progress in all those areas. One measure of progress is publications and invited material. The research described here has led to more than 43 papers that are published, accepted, or submitted to refereed journals, and to 15 invited presentations at conferences and workshops.

  3. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  4. Cosmological and astrophysical implications of sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Petraki, Kalliopi

    compelling dark-matter candidate which may alleviate some of the discrepancies that appear between the traditional cold dark matter scenario and the observed small-scale structure of the universe. Heavier and unstable sterile neutrinos may play an important role in compact astrophysical objects. Weakly coupled sterile neutrinos of mass of about 200 MeV, produced in the core of a supernova, can facilitate the energy transport from the core to the shock front. This is critical for the successful propagation of the shock in supernovae, and the fate of the star. The mediation of sterile neutrinos, which may be the missing piece of physics in the explosion mechanism, yields an observable signature that can help test this scenario.

  5. Validating Prior Geological Scenario Uncertainty with Geophysical Data

    NASA Astrophysics Data System (ADS)

    Scheidt, C.; Jeong, C.; Mukerji, T.; Caers, J.

    2014-12-01

    Subsurface reservoir modelling, whether for groundwater, storage or oil/gas production relies on geophysical data for determining structure, rocks and fluid variations. The traditional approach depends on stochastic inversion of the geophysical image into subsurface models. However, in addition to geophysical data a wealth of geological information is available from analog or previous studies. Most of this information is ignored, and inversions resort to more mathematically-inspired priors often based on covariance models. In this presentation, using a real field application, we propose a method to validate a rich geological prior with geophysical data without the need for costly inversions. The result of this work is a wide, but geologically-realistic prior that can then be used in subsequent stochastic inversions. To achieve this, we propose to validate plausible geological models (from analog studies) with the observed geophysical data through a global, pattern-based measure of dissimilarity. This global dissimilarity measure is defined between the forward simulated geophysical response of a large variety of geologically plausible models and the observed field data. The proposed dissimilarity measure relies on a comparison of the wavelet decompositions between observed and forward simulated geophysical responses. The difference in frequency distribution of the wavelet coefficients is used via a JS-divergence measure to define the dissimilarity between all the subsurface models and the observed data. The proposed approach is applied to a real field offshore reservoir in West Africa, where a 3D seismic cube is available. The uncertain geological parameters defined for this case are the rock physic model, the infill channels size, depth, sinuosity, the proportion of sand/shale and the stacking patterns.

  6. The Center for Astrophysical Research in Antarctica

    NASA Astrophysics Data System (ADS)

    Harper, D. A.

    1998-09-01

    The Antarctic Plateau is the coldest, driest place on earth. Instruments deployed there enjoy unique advantages for observations requiring (1) the lowest possible thermal background emission, (2) the high transparency and extreme stablity of the Antarctic atmosphere at wavelengths sensitive to water vapor absorption, or (3) continuous access to the polar sky. The Center for Astrophysical Research in Antarctica (CARA) was formed in 1991 to establish observatory at the South Pole and to pursue a set of research projects which can exploit the unique advantages of the site. The projects are knit together by overlapping scientific questions being approached with instruments sensitive to wavelengths from one micron to one millimeter; by the logistical aspects of running a common observatory at a remote site; and by a common type of experiment which places emphasis on large scale, uniform, high sensitivity observations. Center projects study the spatial structure of the cosmic microwave background, star and planet formation, galaxy structure and evolution, and the physics and chemistry of the interstellar medium. During the past seven years, CARA has established a year-round observatory at the South Pole; confirmed the transparency, darkness, and stability of the Antarctic sky; installed four major telescope facilities, and used them to conduct scientific investigations. Now, with facilities in place, with established methods of operating equipment in the antarctic environment, with a knowledge of the site characteristics in hand, and with a major modernization program underway at the Amundsen-Scott South Pole Station, the potential of the South Pole site for astrophysical research is only beginning to be realized. Future instruments of exceptional resolution and sensitivity are possible and would provide a valuable complement to airborne and space-based telescopes which will be deployed during the first decades of the new century.

  7. Atomic Data in X-Ray Astrophysics

    NASA Technical Reports Server (NTRS)

    Brickhouse, N. S.

    2000-01-01

    With the launches of the Chandra X-ray Observatory (CXO) and the X-ray Multimirror Mission (XMM) and the upcoming launch of the Japanese mission ASTRO-E, high resolution X-ray spectroscopy of cosmic sources has begun. Early, deep observations of three stellar coronal sources will provide not only invaluable calibration data, but will also give us benchmarks for the atomic data under collisional equilibrium conditions. Analysis of the Chandra X-ray Observatory data, and data from other telescopes taken simultaneously, for these stars is ongoing as part of the Emission Line Project. Goals of the Emission Line Project are: (1) to determine and verify accurate and robust diagnostics and (2) to identify and prioritize issues in fundamental spectroscopy which will require further theoretical and/or laboratory work. The Astrophysical Plasma Emission Database will be described in some detail, as it is introducing standardization and flexibility into X-ray spectral modeling. Spectral models of X-ray astrophysical plasmas can be generally classified as dominated by either collisional ionization or by X-ray photoionization. While the atomic data needs for spectral models under these two types of ionization are significantly different, there axe overlapping data needs, as I will describe. Early results from the Emission Line Project benchmarks are providing an invaluable starting place, but continuing work to improve the accuracy and completeness of atomic data is needed. Additionally, we consider the possibility that some sources will require that both collisional ionization and photoionization be taken into account, or that time-dependent ionization be considered. Thus plasma spectral models of general use need to be computed over a wide range of physical conditions.

  8. Physics in the Twentieth Century

    ERIC Educational Resources Information Center

    Weisskopf, Victor F.

    1970-01-01

    Provides a review of the great discoveries, theoretical concepts and development of physics in the 20th century. The growth and significance of diverse fields such as quantum theory, relativity theory, atomic physics, molecular physics, the physics of the solid state, nuclear physics, astrophysics, plasma physics, and particle physics are…

  9. Einstein Toolkit for Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Collaborative Effort

    2011-02-01

    The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.

  10. Astrophysics and Cosmology: International Partnerships

    NASA Astrophysics Data System (ADS)

    Blandford, Roger

    2015-04-01

    Most large projects in astrophysics and cosmology are international. This raises many challenges including: • Aligning the sequence of: proposal, planning, selection, funding, construction, deployment, operation, data mining in different countries • Managing to minimize cost growth through reconciling different practices • Communicating at all levels to ensure a successful outcome • Stabilizing long term career opportunities. There has been considerable progress in confronting these challenges. Lessons learned from past collaborations are influencing current facilities but much remains to be done if we are to optimize the scientific and public return on the expenditure of financial and human resources.

  11. Astrophysics and Cosmology: International Partnerships

    NASA Astrophysics Data System (ADS)

    Blandford, Roger

    2016-03-01

    Most large projects in astrophysics and cosmology are international. This raises many challenges including: --Aligning the sequence of: proposal, planning, selection, funding, construction, deployment, operation, data mining in different countries --Managing to minimize cost growth through reconciling different practices --Communicating at all levels to ensure a successful outcome --Stabilizing long term career opportunities. There has been considerable progress in confronting these challenges. Lessons learned from past collaborations are influencing current facilities but much remains to be done if we are to optimize the scientific and public return on the expenditure of financial and human resources.

  12. Astrophysics Source Code Library Enhancements

    NASA Astrophysics Data System (ADS)

    Hanisch, R. J.; Allen, A.; Berriman, G. B.; DuPrie, K.; Mink, J.; Nemiroff, R. J.; Schmidt, J.; Shamir, L.; Shortridge, K.; Taylor, M.; Teuben, P. J.; Wallin, J.

    2015-09-01

    The Astrophysics Source Code Library (ASCL)1 is a free online registry of codes used in astronomy research; it currently contains over 900 codes and is indexed by ADS. The ASCL has recently moved a new infrastructure into production. The new site provides a true database for the code entries and integrates the WordPress news and information pages and the discussion forum into one site. Previous capabilities are retained and permalinks to ascl.net continue to work. This improvement offers more functionality and flexibility than the previous site, is easier to maintain, and offers new possibilities for collaboration. This paper covers these recent changes to the ASCL.

  13. Low frequency gravitational wave astrophysics

    NASA Astrophysics Data System (ADS)

    Larson, Shane

    The field of low-frequency gravitational wave astronomy is evolving as the design of the Laser Interferometer Space Antenna (LISA) is in flux. Changing mission architectures naturally has an impact on the science goals and science capabilities in gravitational wave astronomy, requiring astrophysicists to pursue a deeper understanding on three fronts. (1) What astrophysical knowledge can be extracted from populations of sources based on their relative strengths in the data streams? (2) How are the science returns maximized as detector capabilities evolve? (3) How do evolving detector performance expectations alter the science that is possible with space- based gravitational wave detectors? This work proposes a series of investigations that address these questions along two broad avenues of inquiry. The first thrust of this effort is designed to examine how the population of ultra-compact galactic binaries can be better characterized by multi-messenger observations and statistical population analyses. While these investigations are astrophysical interesting in and of themselves, they are particularly relevant as detector designs evolve because the binaries are a limiting source of astrophysical noise that must be mitigated in order to maximize the science return for other sources, such as massive binary black hole inspirals and extreme mass ratio inspirals. The second thrust of this effort is geared toward characterization of the detector itself, since this ultimately fixes our ability to answer astrophysical questions. While many high-fidelity simulators exist for the original LISA mission architecture, the work proposed here will develop a new, flexible suite of prototyping tools analogous to the "Online Sensitivity Curve Generator" (which the PI authored). These tools will allow astrophysicists and data analysts alike to rapidly assess whether new proposed architectures for a space-based gravitational wave observatory will enhance or adversely impact the science

  14. Ion irradiation of ices relevant to astrophysics

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Brunetto, R.; Leto, G.; Palumbo, M. E.; Spinella, F.; Strazzulla, G.

    Ices, silicates, and carbonaceous materials have been observed in different astrophysical environments such as the interstellar medium, circumstellar regions, comets, and solid surfaces of Solar System objects. In space these materials suffer from processing caused by cosmic rays, photons and thermal annealing. Our knowledge of the effects of processing on the evolution of solids in different astrophysical environments in mainly based on laboratory experiments. The Laboratory of Experimental Astrophysics in Catania (Italy) is equipped to study the effects of processing on astrophysical relevant materials. Here we briefly describe the experimental set up and discuss some recent results.

  15. High-Energy Astrophysics: An Overview

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    2007-01-01

    High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.

  16. Working Papers: Astronomy and Astrophysics Panel Reports

    NASA Technical Reports Server (NTRS)

    Bahcall, John N.; Beichman, Charles A.; Canizares, Claude; Cronin, James; Heeschen, David; Houck, James; Hunten, Donald; Mckee, Christopher F.; Noyes, Robert; Ostriker, Jeremiah P.

    1991-01-01

    The papers of the panels appointed by the Astronomy and Astrophysics survey Committee are compiled. These papers were advisory to the survey committee and represent the opinions of the members of each panel in the context of their individual charges. The following subject areas are covered: radio astronomy, infrared astronomy, optical/IR from ground, UV-optical from space, interferometry, high energy from space, particle astrophysics, theory and laboratory astrophysics, solar astronomy, planetary astronomy, computing and data processing, policy opportunities, benefits to the nation from astronomy and astrophysics, status of the profession, and science opportunities.

  17. High Energy Astrophysics Research and Programmatic Support

    NASA Technical Reports Server (NTRS)

    Angelini, Lorella

    1998-01-01

    This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

  18. High Energy Astrophysics Research and Programmatic Support

    NASA Technical Reports Server (NTRS)

    Angelini, L. (Editor)

    1997-01-01

    This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

  19. Magnetic Reconnection in Extreme Astrophysical Environments

    NASA Astrophysics Data System (ADS)

    Uzdensky, Dmitri A.

    2011-10-01

    Magnetic reconnection is a fundamental plasma physics process in which ideal-MHD's frozen-in constraints are broken and the magnetic field topology is dramatically re-arranged, which often leads to a violent release of the free magnetic energy. Most of the magnetic reconnection research done to date has been motivated by the applications to systems such as the solar corona, Earth's magnetosphere, and magnetic confinement devices for thermonuclear fusion. These environments have relatively low energy densities and the plasma is adequately described as a mixture of equal numbers of electrons and ions and where the dissipated magnetic energy always stays with the plasma. In contrast, in this paper I would like to introduce a different, new direction of research—reconnection in high energy density radiative plasmas, in which photons play as important a role as electrons and ions; in particular, in which radiation pressure and radiative cooling become dominant factors in the pressure and energy balance. This research is motivated in part by rapid theoretical and experimental advances in High Energy Density Physics, and in part by several important problems in modern high-energy astrophysics. I first discuss some astrophysical examples of high-energy-density reconnection and then identify the key physical processes that distinguish them from traditional reconnection. Among the most important of these processes are: special-relativistic effects; radiative effects (radiative cooling, radiation pressure, and radiative resistivity); and, at the most extreme end—QED effects, including pair creation. The most notable among the astrophysical applications are situations involving magnetar-strength fields (1014-1015 G, exceeding the quantum critical field B ∗≃4×1013 G). The most important examples are giant flares in soft gamma repeaters (SGRs) and magnetic models of the central engines and relativistic jets of Gamma Ray Bursts (GRBs). The magnetic energy density in

  20. The next century astrophysics program

    NASA Technical Reports Server (NTRS)

    Swanson, Paul N.

    1992-01-01

    The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of flagship and intermediate missions that are presently under study for possible launch during the next 20 years. These missions and tentative schedules, referred to as the Astrotech 21 Mission Set, are summarized. The missions are in three groups corresponding to the cognizant science branch within the Astrophysics Division. Phase C/D refers to the pre-launch construction and delivery of the spacecraft, and the Operations Phase refers to the period when the mission is active in space. Approximately 1.5 years before the start of Phase C/D, a non-advocate review (NAR) is held to ensure that the mission/system concept and the requisite technology are at an appropriate stage of readiness for full scale development to begin. Therefore, technology development is frozen (usually) as of the date of a successful NAR. An overview of the technology advances required for each of the three wavelength groups is provided in the following paragraphs, along with a brief description of the individual missions.

  1. NASA Astrophysics E/PO Impact: The Astrophysics Educator Ambassador Program

    NASA Astrophysics Data System (ADS)

    Cominsky, Lynn R.; McLin, Kevin M.; SSU E/PO Team

    2015-01-01

    The NASA Astrophysics Educator Ambassador (EA) Program began in 2001 as part of the GLAST (now Fermi) E/PO effort at Sonoma State University. The program currently supports 15 EAs, sponsored by either Fermi, Swift, XMM-Newton or NuSTAR. This group of master educators work with mission scientists and E/PO personnel to develop curricula and train teachers; they also do workshops for students and outreach events with the general public. We have held six bi-annual weeklong trainings at SSU: each has had a different focus. Special topics of study have included the Dark Universe, Particle Physics and Gravitation. Additionally, time is given for the EAs to share ideas from their own workshops. In the 14 years of the program, the total number of teachers attending EA-run workshops is over 65,000. Over 1500 workshops have been evaluated by participants, and these evaluation scores and comments have been further analyzed by external experts at WestEd. The WestEd report summarizes the results: "Almost universally high ratings are obtained even though a wide range of participants by grade level, teaching experience or interest typically attends EA conference sessions, and they can bring quite different needs or perspectives." In this talk, I will report details of the impacts of the Astrophysics EA program.

  2. Geophysical applications of satellite altimetry

    SciTech Connect

    Sandwell, D.T. )

    1991-01-01

    Publications related to geophysical applications of Seasat and Geosat altimetry are reviewed for the period 1987-1990. Problems discussed include geoid and gravity errors, regional geoid heights and gravity anomalies, local gravity field/flexure, plate tectonics, and gridded geoid heights/gravity anomalies. 99 refs.

  3. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    USGS Publications Warehouse

    Seeley, Robert L.; Daniels, Jeffrey J.

    1984-01-01

    A system has been developed to simultaneously sample and transmit digital data from five remote geophysical data receiver stations to a control station that processes, displays, and stores the data. A microprocessor in each remote station receives commands from the control station over a single telemetry channel.

  4. MPI-AMRVAC FOR SOLAR AND ASTROPHYSICS

    SciTech Connect

    Porth, O.; Xia, C.; Hendrix, T.; Moschou, S. P.; Keppens, R.

    2014-09-01

    In this paper, we present an update to the open source MPI-AMRVAC simulation toolkit where we focus on solar and non-relativistic astrophysical magnetofluid dynamics. We highlight recent developments in terms of physics modules, such as hydrodynamics with dust coupling and the conservative implementation of Hall magnetohydrodynamics. A simple conservative high-order finite difference scheme that works in combination with all available physics modules is introduced and demonstrated with the example of monotonicity-preserving fifth-order reconstruction. Strong stability-preserving high-order Runge-Kutta time steppers are used to obtain stable evolutions in multi-dimensional applications, realizing up to fourth-order accuracy in space and time. With the new distinction between active and passive grid cells, MPI-AMRVAC is ideally suited to simulate evolutions where parts of the solution are controlled analytically or have a tendency to progress into or out of a stationary state. Typical test problems and representative applications are discussed with an outlook toward follow-up research. Finally, we discuss the parallel scaling of the code and demonstrate excellent weak scaling up to 30, 000 processors, allowing us to exploit modern peta-scale infrastructure.

  5. MPI-AMRVAC for Solar and Astrophysics

    NASA Astrophysics Data System (ADS)

    Porth, O.; Xia, C.; Hendrix, T.; Moschou, S. P.; Keppens, R.

    2014-09-01

    In this paper, we present an update to the open source MPI-AMRVAC simulation toolkit where we focus on solar and non-relativistic astrophysical magnetofluid dynamics. We highlight recent developments in terms of physics modules, such as hydrodynamics with dust coupling and the conservative implementation of Hall magnetohydrodynamics. A simple conservative high-order finite difference scheme that works in combination with all available physics modules is introduced and demonstrated with the example of monotonicity-preserving fifth-order reconstruction. Strong stability-preserving high-order Runge-Kutta time steppers are used to obtain stable evolutions in multi-dimensional applications, realizing up to fourth-order accuracy in space and time. With the new distinction between active and passive grid cells, MPI-AMRVAC is ideally suited to simulate evolutions where parts of the solution are controlled analytically or have a tendency to progress into or out of a stationary state. Typical test problems and representative applications are discussed with an outlook toward follow-up research. Finally, we discuss the parallel scaling of the code and demonstrate excellent weak scaling up to 30, 000 processors, allowing us to exploit modern peta-scale infrastructure.

  6. Astrophysical Probes of New Models of Dark Matter

    NASA Astrophysics Data System (ADS)

    Zurek, Kathryn

    One of the most pressing and relevant cosmological questions is on the nature of the dark matter. I propose a comprehensive program at the boundary of astrophysics and cosmology with particle physics, focused on the question on the nature of the Dark Matter (DM). Research at the boundary of the two fields is critically important as a plethora of experiments in both particle physics and astrophysics, such as direct and indirect detection of Dark Matter (DM) by the Fermi Gamma Ray Space Telescope (FGST), AMS-02, and Cosmic Microwave Background probes such as Planck, come online. At the same time, data from the Large Hadron Collider (LHC) will probe fundamental questions about Electroweak Symmetry Breaking and its implications for astrophysics and cosmology, as concerns especially the nature of the DM and the generation of the baryon asymmetry. Physics beyond the Standard Model (SM) is required to explain the astrophysical observation that DM dominates over ordinary matter by a ratio 5:1, as we learned through WMAP, as well as large scale structure surveys. Despite lacking an understanding of the properties of the DM, its presence is crucial for the formation of structure in the universe. Particle physics provides a framework for understanding what the DM could be. This proposal centers on building new models of DM, as well as studying their signatures both in the galaxy and on earth. While particle physics has provided a few popular candidates for DM (such as the supersymmetric neutralino), whose signatures have been extensively studied in the literature, it is important to consider other theoretically motivated candidates which provide distinct signatures. This proposal focuses on such new models of DM, especially models of DM from hidden sectors. For example, recently, the PAMELA experiment has observed a rise in the ratio of positron to electron flux at high energies. The flux may likely come from astrophysical objects nearby, such as pulsars. An intriguing

  7. Space astronomy and astrophysics program by NASA

    NASA Astrophysics Data System (ADS)

    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. Dunlop receives European Geophysical Society's Néel Medal

    NASA Astrophysics Data System (ADS)

    Tauxe, Lisa

    David J. Dunlop of the Physics Department and Erindale College at the University of Toronto has been awarded the 1999 Louis Néel Medal of the European Geophysical Society (EGS) for “authoritative contributions to rock magnetism, setting the standards for future decades.” The medal will be presented to Dunlop in April in a special ceremony at the Nederlands Congresbebouw in The Hague, The Netherlands, during the 24th General Assembly of the EGS.The Néel Medal is awarded by the Solid Earth Geophysics section of EGS in recognition of the scientific achievements of Louis Néel, who shared the 1970 Nobel Prize in Physics for his fundamental discoveries in magnetism.The medal is awarded “for outstanding achievements in the fertilization of the Earth Sciences by the transfer and application of fundamental theory and/or experimental techniques of solid state physics, defined in its broadest sense.”

  9. Contemporary Aspects of Atomic Physics

    ERIC Educational Resources Information Center

    Knott, R. G. A.

    1972-01-01

    The approach generally used in writing undergraduate textbooks on Atomic and Nuclear Physics presents this branch as historical in nature. Describes the concepts of astrophysics, plasma physics and spectroscopy as contemporary and intriguing for modern scientists. (PS)

  10. Forward physics of hadronic colliders

    NASA Astrophysics Data System (ADS)

    Ivanov, I. P.

    2013-12-01

    These lectures were given at the Baikal Summer School on Physics of Elementary Particles and Astrophysics in July 2012. They can be viewed as a concise introduction to hadronic diffraction, to the physics of the Pomeron and related topics.

  11. Computational Relativistic Astrophysics Using the Flowfield-Dependent Variation Theory

    NASA Technical Reports Server (NTRS)

    Richardson, G. A.; Chung, T. J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Theoretical models, observations and measurements have preoccupied astrophysicists for many centuries. Only in recent years, has the theory of relativity as applied to astrophysical flows met the challenges of how the governing equations can be solved numerically with accuracy and efficiency. Even without the effects of relativity, the physics of magnetohydrodynamic flow instability, turbulence, radiation, and enhanced transport in accretion disks has not been completely resolved. Relativistic effects become pronounced in such cases as jet formation from black hole magnetized accretion disks and also in the study of Gamma-Ray bursts (GRB). Thus, our concern in this paper is to reexamine existing numerical simulation tools as to the accuracy and efficiency of computations and introduce a new approach known as the flowfield-dependent variation (FDV) method. The main feature of the FDV method consists of accommodating discontinuities of shock waves and high gradients of flow variables such as occur in turbulence and unstable motions. In this paper, the physics involved in the solution of relativistic hydrodynamics and solution strategies of the FDV theory are elaborated. The general relativistic astrophysical flow and shock solver (GRAFSS) is introduced, and some simple example problems for Computational Relativistic Astrophysics (CRA) are demonstrated.

  12. The Iron Project:. Radiative Atomic Processes in Astrophysics

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana N.

    2011-06-01

    Astronomical objects, such as, stars, galaxies, blackhole environments, etc are studied through their spectra produced by various atomic processes in their plasmas. The positions, shifts, and strengths of the spectral lines provide information on physical processes with elements in all ionization states, and various diagnostics for temperature, density, distance, etc of these objects. With presence of a radiative source, such as a star, the astrophysical plasma is dominated by radiative atomic processes such as photoionization, electron-ion recombination, bound-bound transitions or photo-excitations and de-excitations. The relevant atomic parameters, such as photoionization cross sections, electron-ion recombination rate coefficients, oscillator strengths, radiative transition rates, rates for dielectronic satellite lines etc are needed to be highly accurate for precise diagnostics of physical conditions as well as accurate modeling, such as, for opacities of astrophysical plasmas. for opacities of astrophysical plasmas. This report illustrates detailed features of radiative atomic processes obtained from accurate ab initio methods of the latest developments in theoretical quantum mechanical calculations, especially under the international collaborations known as the Iron Project (IP) and the Opacity Project (OP). These projects aim in accurate study of radiative and collsional atomic processes of all astrophysically abundant atoms and ions, from hydrogen to nickel, and calculate stellar opacities and have resulted in a large number of atomic parameters for photoionization and radiative transition probabilities. The unified method, which is an extension of the OP and the IP, is a self-consistent treatment for the total electron-ion recombination and photoionization. It incorporates both the radiative and the dielectronic recombination processes and provides total recombination rates and level-specific recombination rates for hundreds of levels for a wide range of

  13. Nuclear Astrophysics with the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; Lamia, L.; Pizzone, R. G.; Cherubini, S.; Gulino, M.; La Cognata, M.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartá, R.

    2016-01-01

    The Trojan Horse Method (THM) represents the indirect path to determine the bare nucleus astrophysical S(E) factor for reactions between charged particles at astrophysical energies. This is done by measuring the quasi free cross section of a suitable three body process. The basic features of the THM will be presented together with some applications to demonstrate its practical use.

  14. Proceedings of the NASA Laboratory Astrophysics Workshop

    NASA Technical Reports Server (NTRS)

    Weck, Phillippe F. (Editor); Kwong, Victor H. S. (Editor); Salama, Farid (Editor)

    2006-01-01

    This report is a collection of papers presented at the 2006 NASA Workshop on Laboratory Astrophysics held in the University of Nevada, Las Vegas (UNLV) from February 14 to 16, 2006. This workshop brings together producers and users of laboratory astrophysics data so that they can understand each other's needs and limitations in the context of the needs for NASA's missions. The last NASA-sponsored workshop was held in 2002 at Ames Research Center. Recent related meetings include the Topical Session at the AAS meeting and the European workshop at Pillnitz, Germany, both of which were held in June 2005. The former showcased the importance of laboratory astrophysics to the community at large, while the European workshop highlighted a multi-laboratory approach to providing the needed data. The 2006 NASA Workshop on Laboratory Astrophysics, sponsored by the NASA Astrophysics Division, focused on the current status of the field and its relevance to NASA. This workshop attracted 105 participants and 82 papers of which 19 were invited. A White Paper identifying the key issues in laboratory astrophysics during the break-out sessions was prepared by the Scientific Organizing Committee, and has been forwarded to the Universe Working Group (UWG) at NASA Headquarters. This White Paper, which represented the collective inputs and opinions from experts and stakeholders in the field of astrophysics, should serve as the working document for the future development of NASA's R&A program in laboratory astrophysics.

  15. Digital Underground (Shh. It's really Applied Geophysics!)

    NASA Astrophysics Data System (ADS)

    McAdoo, B. G.

    2003-12-01

    Digital Underground (Geology/Physics 241) at Vassar College is an applied geophysics course designed for a liberal arts curriculum, and has nothing to do with Shock G and Tupac Shakur. Applied geophysics courses have a history of using geophysical methods on environmental contamination-type applications (underground storage tanks, leach fields, etc.). Inspired in large part by the Keck Geology Consortium project run by Franklin and Marshall College geophysicist (Robert Sternberg) and archaeologist (James Delle) in an old slave village in Jamaica in 1999, this class examines the history of slavery in New York's Hudson Valley region by way of its forgotten African-American graveyards. This multidisciplinary approach to an issue draws students from across the curriculum- we have had our compliments of geologists and physicists, along with students from sociology, environmental studies, history, and Africana studies. The name of the class and content are designed to attract a non-traditional student of geophysics.- The project-based nature of the class appeals to student yearning for an out-of-classroom experience. The uncontrolled nature of the class demonstrates the complications that occur in real-word situations. The class has in the past broken itself into two teams- a surveying team and an archival research team. Archival research is done (usually by the social scientists in the class) to add a human dimension to the geophysical. The surveying equipment used in delineating these forgotten graveyards includes a Total Station surveyor, an electrical resistivity meter, a magnetometer, and a ground penetrating radar. All students must have a rudimentary understanding of the physics behind the equipment (to the level of where they can explain it to the general public), and the methods used by those studying the archives. This is a project-based class, where the instructor acts as a project manager, and the students make the decisions regarding the survey itself. Every

  16. Calculation of astrophysical S factor at low energy levels

    NASA Astrophysics Data System (ADS)

    Andic, Halil Ibrahim; Ozer, Okan

    2017-02-01

    Nuclear reactions are very important for the structure, evolution, nucleosynthesis and various observational manifestations of main-sequence stars, white dwarfs and neutron stars. For astrophysical applications, one needs to know value of S-factor for many reactions at low energies. The experimental measurements of cross-sections at such low energies are essentially not easily available since the Coulomb barrier. Theoretical calculations are model dependent, so that nuclear physics uncertainties of calculated S-factor can be substantial. Using the supersymmetric quantum mechanics one can obtain the supersymmetric partner potential that can vary by several orders of magnitude in the energy range of a given reaction in the calculation of S factor. Since the determination of reaction rates requires accurate values of cross sections at very low energies, then in order to eliminate the main part of the energy dependence of these cross sections one makes use of the astrophysical S-factor in Taylor Expansion series about zero-energy.

  17. Astrophysical bags - A new paradigm for active galactic nuclei?

    NASA Technical Reports Server (NTRS)

    Wilson, Thomas L.

    1992-01-01

    Active galaxies are believed to consist of a compact nucleus, the standard model for which is a massive black hole or a cluster of black holes. A different paradigm is considered here, deriving from quark confinement theory in QCD. It is an 'astrophysical bag', modelled after the 'hadron bags' of particle physics which have already been studied in astrophysics as quark stars. Another interpretation of the cosmological constant in general relativity, and possibly a new quasar redshift formula, are introduced. As a highly-energetic object, this model may resolve the baryonic matter problem for fuelling AGN accretion processes which black hole paradigms cannot account for. Here, baryons, cosmic rays, and neutrinos are free.

  18. Heavy Particle Collision Data for Fusion and Astrophysics

    SciTech Connect

    Schultz, David R.

    2011-05-11

    A wide range of applications, for example, diagnostics and modeling of fusion plasmas, interpretation of astronomical observations and modeling of astrophysical environments, and simulation of material processing plasmas, require large, accurate, and complete collections of data for electron, photon, heavy particle, and surface interactions. Consequently, over several decades, experimental and theoretical efforts have been developed in order to measure or to calculate such data, and to synergistically explore the fundamental physical mechanisms that underlie interactions at the atomic scale. The present report illustrates some of the recent progress in development of techniques and their use in describing heavy particle collisions, in particular, those involving ions interacting with atoms and simple molecules, with specific applications of the resulting data in fusion energy research and astrophysics.

  19. Heavy Particle Collision Data for Fusion and Astrophysics

    SciTech Connect

    Schultz, David Robert

    2011-01-01

    A wide range of applications, for example, diagnostics and modeling of fusion plasmas, interpretation of astronomical observations and modeling of astrophysical environments, and simulation of material processing plasmas, require large, accurate, and complete collections of data for electron, photon, heavy particle, and surface interactions. Consequently, over several decades, experimental and theoretical efforts have been developed in order to measure or to calculate such data, and to synergistically explore the fundamental physical mechanisms that underlie interactions at the atomic scale. The present report illustrates some of the recent progress in development of techniques and their use in describing heavy particle collisions, in particular, those involving ions interacting with atoms and simple molecules, with specific applications of the resulting data in fusion energy research and astrophysics.

  20. CoffeeShop Astrophysics: An Adventure in Public Outreach

    NASA Astrophysics Data System (ADS)

    Chamberlin, Sydney; Decesar, Megan; Caudill, Sarah; Sadeghian, Laleh; Nuttall, Laura; Urban, Alex; McGrath, Casey

    2016-03-01

    Engaging non-scientists in scientific discussions is inarguably important, both for researchers and society. Public lectures have long been utilized as a method for performing such outreach, but due to their format and location often reach a limited audience. More recently, events such as science cafés (events pairing a scientist with the public in a casual venue) have emerged as a potential tool for connecting with general audiences. The success of these events depends on multiple variables. In this talk, we describe an example of such an event entitled CoffeeShop Astrophysics, that uses multiple speakers, demonstrations and humor to successfully engage members of the public. We discuss the key elements that make CoffeeShop Astrophysics effective, and the viability of grassroots, coffeeshop-style outreach. The authors gratefully acknowledge support from the American Physical Society for this work.

  1. Modified gravity inside astrophysical bodies

    SciTech Connect

    Saito, Ryo; Langlois, David; Yamauchi, Daisuke; Mizuno, Shuntaro; Gleyzes, Jérôme E-mail: yamauchi@resceu.s.u-tokyo.ac.jp E-mail: jerome.gleyzes@cea.fr

    2015-06-01

    Many theories of modified gravity, including the well studied Horndeski models, are characterized by a screening mechanism that ensures that standard gravity is recovered near astrophysical bodies. In a recently introduced class of gravitational theories that goes beyond Horndeski, it has been found that new derivative interactions lead to a partial breaking of the Vainshtein screening mechanism inside any gravitational source, although not outside. We study the impact of this new type of deviation from standard gravity on the density profile of a spherically symmetric matter distribution, in the nonrelativistic limit. For simplicity, we consider a polytropic equation of state and derive the modifications to the standard Lane-Emden equations. We also show the existence of a universal upper bound on the amplitude of this type of modified gravity, independently of the details of the equation of state.

  2. Photohadronic Processes in Astrophysical Environments

    NASA Astrophysics Data System (ADS)

    Mücke, A.; Rachen, J. P.; Engel, Ralph; Protheroe, R. J.; Stanev, Todor

    1999-08-01

    We discuss the first applications of our newly developed Monte Carlo event generator SOPHIA to multiparticle photoproduction of relativistic protons with thermal and power-law radiation fields. The measured total cross section is reproduced in terms of excitation and decay of baryon resonances, direct pion production, diffractive scattering, and non-diffractive multiparticle production. Non-diffractive multiparticle production is described using a string fragmentation model. We demonstrate that the widely used `Δ-approximation' for the photoproduction cross section is reasonable only for a restricted set of astrophysical applications. The relevance of this result for cosmic ray propagation through the microwave background and hadronic models of active galactic nuclei and gamma-ray bursts is briefly discussed.

  3. Astrophysical applications of quasar microlensing

    NASA Astrophysics Data System (ADS)

    Mediavilla, E.; Jiménez-Vicente, J.; Muñoz, J. A.

    2017-03-01

    We present a quick overview of several examples that illustrate the application of quasar microlensing to various problems of great interest in Astrophysics and Cosmology. We start introducing the main tool for simulating quasar microlensing, the magnification map. Then, the flux magnification statistics obtained from the magnification maps is used to study the quasar accretion disk size and temperature profile with results that challenge the thin disk model. The microlensing flux magnification statistics is also useful to determine the radial slope of the dark matter distribution in lens galaxies. The extremely high microlensing magnification at caustics allows to scan with horizon scale accuracy the quasar accretion disk, spiraling around the central super massive black hole, resolving the innermost stable circular orbit. Finally, transverse peculiar velocities of the lens galaxies, of great interest in cosmology, can be inferred either counting peaks in the microlensing light curves or directly from astrometric measurements of the highly magnified relative motions between lensed quasar images.

  4. Astrophysically Interesting Resonances; Another Approach

    NASA Astrophysics Data System (ADS)

    Austin, Roby; Jenkins, David

    2008-10-01

    R.A.E. Austin, R. Kanungo, A. Campbell, S. Colosimo, S. Reeve Saint Mary's University; D.G. Jenkins, C.Aa.Diget, A. Robinson, University of York, UK; P.J. Woods T. Davinson University of Edinburgh; C.-Y. Wu A. Hurst J.A. Becker Lawrence Livermore National Laboratory; G.C. Ball M. Djongolov G. Hackman A.C. Morton, C. Pearson, S.J. Williams TRIUMF; A.A. Phillips, M. Schumaker, University of Guelph H.Boston, A. Grint, D. Oxley, University of Liverpool; D. Cline, A. Hayes, University of Rochester; We describe a prototype experiment to measure resonances of interest in astrophysical reactions. We use the TIGRESS to detect gamma rays in coincidence with charged particles, inelastically scattered in inverse kinematics. The particles are detected with the Bambino detector modified to a δE-E silicon telescope spanning 15-40 degrees in the lab.

  5. Analysis of geophysical measurements and spacecraft interactions

    NASA Astrophysics Data System (ADS)

    Bass, J. N.; Bhavnani, K. H.; Bonito, N. A.; Bounar, K. H.; Grady, P. L.

    1993-01-01

    Investigations were supported to analyze geophysical measurements with integrated applications of ephemerides physics and mathematics of the ionosphere and near space. The projects undertaken included analytical and computational simulation of the interactive spacecraft processes associated with the following: charging, contamination, liquid venting, and critical ionization velocity; data based and analytical investigations of trapped particles, dosage, magnetic fields, and instrumentation for the CRRES experiment; and data based studies of auroral electron and ion precipitation including neural network techniques, ionospheric scintillation and OTH backscatter, and atmospheric density and orbital decay. Systems were developed and applied for calibration and processing of the CRRES and APEX magnetometers, and for generation of satellite attitude and ephemeris. Techniques employed for applying coordinate systems, depicting vehicle and astronomical circumstances, and interactively presenting data in conventional and color formats are also described.

  6. Geophysical subsurface imaging and interface identification.

    SciTech Connect

    Pendley, Kevin; Bochev, Pavel Blagoveston; Day, David Minot; Robinson, Allen Conrad; Weiss, Chester Joseph

    2005-09-01

    Electromagnetic induction is a classic geophysical exploration method designed for subsurface characterization--in particular, sensing the presence of geologic heterogeneities and fluids such as groundwater and hydrocarbons. Several approaches to the computational problems associated with predicting and interpreting electromagnetic phenomena in and around the earth are addressed herein. Publications resulting from the project include [31]. To obtain accurate and physically meaningful numerical simulations of natural phenomena, computational algorithms should operate in discrete settings that reflect the structure of governing mathematical models. In section 2, the extension of algebraic multigrid methods for the time domain eddy current equations to the frequency domain problem is discussed. Software was developed and is available in Trilinos ML package. In section 3 we consider finite element approximations of De Rham's complex. We describe how to develop a family of finite element spaces that forms an exact sequence on hexahedral grids. The ensuing family of non-affine finite elements is called a van Welij complex, after the work [37] of van Welij who first proposed a general method for developing tangentially and normally continuous vector fields on hexahedral elements. The use of this complex is illustrated for the eddy current equations and a conservation law problem. Software was developed and is available in the Ptenos finite element package. The more popular methods of geophysical inversion seek solutions to an unconstrained optimization problem by imposing stabilizing constraints in the form of smoothing operators on some enormous set of model parameters (i.e. ''over-parametrize and regularize''). In contrast we investigate an alternative approach whereby sharp jumps in material properties are preserved in the solution by choosing as model parameters a modest set of variables which describe an interface between adjacent regions in physical space. While

  7. New Geophysical Observatory in Uruguay

    NASA Astrophysics Data System (ADS)

    Sanchez Bettucci, L.; Nuñez, P.; Caraballo, R. R.; Ogando, R.

    2013-05-01

    In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of developing the Geosciences. The Astronomical and Geophysical Observatory Aiguá (OAGA) is located within the Cerro Catedral Tourist Farm (-34 ° 20 '0 .89 "S/-54 ° 42 '44.72" W, h: 270m). This has the distinction of being located in the center of the South Atlantic Magnetic Anomaly. Geologically is emplaced in a Neoproterozoic basement, in a region with scarce anthropogenic interference. The OAGA has, since 2012, with a GSM-90FD dIdD v7.0 and GSM-90F Overhauser, both of GEM Systems. In addition has a super-SID receiver provided by the Stanford University SOLAR Center, as a complement for educational purposes. Likewise the installation of a seismograph REF TEK-151-120A and VLF antenna is being done since the beginning of 2013.

  8. Smith heads Reviews of Geophysics

    NASA Astrophysics Data System (ADS)

    On January 1, Jim Smith began his term as editor-in-chief of Reviews of Geophysics. As editor-in-chief, he leads the board of editors in enhancing the journal's role as an integrating force in the geophysical sciences by providing timely overviews of current research and its trends. Smith is already beginning to fulfill the journal's role of providing review papers on topics of broad interest to Union members as well as the occasional definitive review paper on selected topics of narrower focus. Smith will lead the editorial board until December 31, 2000. Michael Coffey, Tommy Dickey, James Horwitz, Roelof Snieder, and Thomas Torgersen have been appointed as editors to serve with Smith. At least one more editor will be named to round out the disciplinary expertise on the board.

  9. BigData as a Driver for Capacity Building in Astrophysics

    NASA Astrophysics Data System (ADS)

    Shastri, Prajval

    2015-08-01

    Exciting public interest in astrophysics acquires new significance in the era of Big Data. Since Big Data involves advanced technologies of both software and hardware, astrophysics with Big Data has the potential to inspire young minds with diverse inclinations - i.e., not just those attracted to physics but also those pursuing engineering careers. Digital technologies have become steadily cheaper, which can enable expansion of the Big Data user pool considerably, especially to communities that may not yet be in the astrophysics mainstream, but have high potential because of access to thesetechnologies. For success, however, capacity building at the early stages becomes key. The development of on-line pedagogical resources in astrophysics, astrostatistics, data-mining and data visualisation that are designed around the big facilities of the future can be an important effort that drives such capacity building, especially if facilitated by the IAU.

  10. GEOPHYSICS: Atmosphere Drives Earth's Tipsiness.

    PubMed

    Kerr, R A

    2000-08-04

    For more than a century, geophysicists who track Earth's rotation have sensed a rhythmic unsteadiness about the planet, an ever-so-slight wobbling whose source remained frustratingly mysterious. But researchers have been homing in on the roots of the so-called Chandler wobble, and now a report in the 1 August issue of Geophysical Research Letters fingers the shifting pressures of the deep sea and ultimately the fickle winds of the atmosphere.

  11. Geophysical Fluid Flow Cell Simulation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Computer simulation of atmospheric flow corresponds well to imges taken during the second Geophysical Fluid Flow Cell (BFFC) mission. The top shows a view from the pole, while the bottom shows a view from the equator. Red corresponds to hot fluid rising while blue shows cold fluid falling. This simulation was developed by Anil Deane of the University of Maryland, College Park and Paul Fischer of Argorne National Laboratory. Credit: NASA/Goddard Space Flight Center

  12. Geophysical monitoring technology for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  13. Air-depolyable geophysics package

    SciTech Connect

    Hunter, S.L.; Harben, P.E.

    1993-11-01

    We are using Lawrence Livermore National Laboratory`s (LLNL`s) diverse expertise to develop a geophysical monitoring system that can survive being dropped into place by a helicopter or airplane. Such an air-deployable system could significantly decrease the time and effort needed to set up such instruments in remote locations following a major earthquake or volcanic eruption. Most currently available geophysical monitoring and survey systems, such as seismic monitoring stations, use sensitive, fragile instrumentation that requires personnel trained and experienced in data acquisition and field setup. Rapid deployment of such equipment can be difficult or impossible. Recent developments in low-power electronics, new materials, and sensors that are resistant to severe impacts have made it possible to develop low-cost geophysical monitoring packages for rapid deployment missions. Our strategy was to focus on low-cost battery-powered systems that would have a relatively long (several months) operational lifetime. We concentrated on the conceptual design and engineering of a single-component seismic system that could survive an air-deployment into an earth material, such as alluvium. Actual implementation of such a system is a goal of future work on this concept. For this project, we drew on LLNL`s Earth Sciences Department, Radio Shop, Plastics Shop, and Weapons Program. The military has had several programs to develop air-deployed and cannon-deployed seismometers. Recently, a sonobuoy manufacturer has offered an air-deployable geophone designed to make relatively soft landings.

  14. Physics.

    ERIC Educational Resources Information Center

    Bromley, D. Allan

    1980-01-01

    The author presents the argument that the past few years, in terms of new discoveries, insights, and questions raised, have been among the most productive in the history of physics. Selected for discussion are some of the most important new developments in physics research. (Author/SA)

  15. AstroDance: Teaching Astrophysics Through Dance?

    NASA Astrophysics Data System (ADS)

    Noel-Storr, Jacob; Campanelli, M.; Bochner, J.; Warfield, T.; Bischof, H.; Zlochower, Y.; Nordhaus, J.; Watkins, G.; NSF CRPA AstroDance Team

    2014-01-01

    Through a collaboration involving scientists, artists and educators, members of the Center for Computational Relativity and Gravitation and the National Technical Institute for the Deaf at the Rochester Institute of Technology we developed a unique project for Communicating Research to Public Audiences. The project used dance and multi-media theater techniques to expose a broad audience, about half of which is comprised of deaf and hard-of-hearing individuals, to an aesthetic, educational performance representing the concepts of gravitational physics in astrophysical settings. Since deaf and hard-of-hearing people rely heavily on visual communication for learning and gaining access to information, dance and multi-media theater provide a kinesthetic and visual experience that is fully accessible to them, as well as hearing audience members, and help facilitate their learning and development of non-linguistic representations of concepts. Here we present the results of our research into the learning outcomes for the diverse audiences of this project in terms of both knowledge and attitudes towards science.

  16. Geophysical Model Research and Results

    SciTech Connect

    Pasyanos, M; Walter, W; Tkalcic, H; Franz, G; Flanagan, M

    2004-07-07

    Geophysical models constitute an important component of calibration for nuclear explosion monitoring. We will focus on four major topics: (1) a priori geophysical models, (2) surface wave models, (3) receiver function derived profiles, and (4) stochastic geophysical models. The first, a priori models, can be used to predict a host of geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. Use of these models is particularly important in aseismic regions or regions without seismic stations, where data of direct measurements might not exist. Lawrence Livermore National Laboratory (LLNL) has developed the Western Eurasia and North Africa (WENA) model which has been evaluated using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis (Pasyanos et al., 2004). We have joined this model with our Yellow Sea - Korean Peninsula (YSKP) model and the Los Alamos National Laboratory (LANL) East Asia model to construct a model for all of Eurasia and North Africa. Secondly, we continue to improve upon our surface wave model by adding more paths. This has allowed us to expand the region to all of Eurasia and into Africa, increase the resolution of our model, and extend results to even shorter periods (7 sec). High-resolution models exist for the Middle East and the YSKP region. The surface wave results can be inverted either alone, or in conjunction with other data, to derive models of the crust and upper mantle structure. We are also using receiver functions, in joint inversions with the surface waves, to produce profiles directly under seismic stations throughout the region. In a collaborative project with Ammon, et al., they have been focusing on stations throughout western Eurasia and North Africa, while we have been focusing on LLNL deployments in the Middle East, including Kuwait, Jordan, and the United Arab Emirates. Finally, we have been

  17. Structure-coupled multiphysics imaging in geophysical sciences

    NASA Astrophysics Data System (ADS)

    Gallardo, Luis A.; Meju, Max A.

    2011-03-01

    Multiphysics imaging or data inversion is of growing importance in many branches of science and engineering. In geophysical sciences, there is a need for combining information from multiple images acquired using different imaging devices and/or modalities because of the potential for accurate predictions. The major challenges are how to combine disparate data from unrelated physical phenomena, taking into account the different spatial scales of the measurement devices, model complexities, and how to quantify the associated uncertainties. This review paper summarizes the role played by the structural gradients-based approach for coupling fundamentally different physical fields in (mainly) geophysical inversion, develops further understanding of this approach to guide newcomers to the field, and defines the main challenges and directions for future research that may be useful in other fields of science and engineering.

  18. Proceedings of the NASA Laboratory Astrophysics Workshop

    NASA Technical Reports Server (NTRS)

    Salama, Farid (Editor)

    2002-01-01

    This document is the proceedings of the NASA Laboratory Astrophysics Workshop, convened May 1-3, 2002 at NASA's Ames Research Center. Sponsored by the NASA Office of Space Science (OSS), this programmatic workshop is held periodically by NASA to discuss the current state of knowledge in the interdisciplinary field of laboratory astrophysics and to identify the science priorities (needs) in support of NASA's space missions. An important goal of the Workshop is to provide input to OSS in the form of a white paper for incorporation in its strategic planning. This report comprises a record of the complete proceedings of the Workshop and the Laboratory Astrophysics White Paper drafted at the Workshop.

  19. Astrophysics at RIA (ARIA) Working Group

    SciTech Connect

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

    2006-07-12

    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.

  20. A tool for Exploring Geophysical Data: The VGEE-IDV

    NASA Astrophysics Data System (ADS)

    Pandya, R. E.; Murray, D.

    2002-12-01

    The Visual Geophysical Exploration Environment (VGEE) is a suite of computer tools and accompanying online curricular units that enable students to develop physical insight from geophysical data sets. The VGEE curriculum is inquiry and visualization based. The curriculum begins by asking students to compare visualizations they construct from authentic geosciences data to their own conception of the geophysical phenomenon. This comparison encourages students to identify and challenge their own prior conceptions of the phenomenon, a necessary prerequisite to successful learning. Students then begin building correct understandings by identifying patterns and relationships within their visualizations. Students use idealized concept models that highlight physical principles to explain these patterns and relationships. Research, however, has shown that the physical insight gained from these idealized models isn't often applied to either the real world or to the data visualized. To address this, students can easily embed these idealized concept models into their visualizations; there the idealized models respond to the real physical conditions of the geophysical data. The entire inquiry process is built around multi-dimensional and multi-variable visualizations of real geophysical data. Advantages of visualization include its using a natural human talent and its removing mathematics as a barrier to insight. Multi-dimensional and multi-variable visualizations offer the additional advantage of integrated perspectives; rather than asking learners to mentally combine two-dimensional representations of different variables, the learners can navigate through a three-dimensional time-varying representation and get a holistic view. Finally, learner constructed visualizations offer the students a experience with scientific tools, a chance to tailor their investigation to their own misconceptions, and the potential for more robust understanding than prepared visualizations. The

  1. NASA Announces 2009 Astronomy and Astrophysics Fellows

    NASA Astrophysics Data System (ADS)

    2009-02-01

    WASHINGTON -- NASA has selected fellows in three areas of astronomy and astrophysics for its Einstein, Hubble, and Sagan Fellowships. The recipients of this year's post-doctoral fellowships will conduct independent research at institutions around the country. "The new fellows are among the best and brightest young astronomers in the world," said Jon Morse, director of the Astrophysics Division in NASA's Science Mission Directorate in Washington. "They already have contributed significantly to studies of how the universe works, the origin of our cosmos and whether we are alone in the cosmos. The fellowships will serve as a springboard for scientific leadership in the years to come, and as an inspiration for the next generation of students and early career researchers." Each fellowship provides support to the awardees for three years. The fellows may pursue their research at any host university or research center of their choosing in the United States. The new fellows will begin their programs in the fall of 2009. "I cannot tell you how much I am looking forward to spending the next few years conducting research in the U.S., thanks to the fellowships," said Karin Oberg, a graduate student in Leiden, The Netherlands. Oberg will study the evolution of water and ices during star formation when she starts her fellowship at the Smithsonian Astrophysical Observatory in Cambridge, Mass. People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Cosmic Heavyweights in Free-for-all Galaxies Coming of Age in Cosmic Blobs Cassiopeia A Comes Alive Across Time and Space A diverse group of 32 young scientists will work on a wide variety of projects, such as understanding supernova hydrodynamics, radio transients, neutron stars, galaxy clusters and the intercluster medium, supermassive black holes, their mergers and the associated gravitational waves, dark energy, dark matter and the reionization process. Other research topics include

  2. Leon Van Speybroeck Wins Astrophysics Bruno Rossi Prize

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts was awarded the 2002 Bruno Rossi Prize of the High-Energy Astrophysics Division of the American Astronomy Society. The Rossi Prize is an arnual recognition of significant contributions in high-energy astrophysics in honor of the Massachusetts Institute of Technology's late Professor Bruno Rossi, an authority on cosmic ray physics and a pioneer in the field of x-ray astronomy. Van Speybroeck, who led the effort to design and make the x-ray mirrors for NASA's premier Chandra X-Ray Observatory, was recognized for a career of stellar achievements in designing precision x-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Huhes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the x-ray mirror assembly that is the heart of the observatory.

  3. Statistical issues in astrophysical searches for particle dark matter

    NASA Astrophysics Data System (ADS)

    Conrad, Jan

    2015-03-01

    In this review statistical issues appearing in astrophysical searches for particle dark matter, i.e. indirect detection (dark matter annihilating into standard model particles) or direct detection (dark matter particles scattering in deep underground detectors) are discussed. One particular aspect of these searches is the presence of very large uncertainties in nuisance parameters (astrophysical factors) that are degenerate with parameters of interest (mass and annihilation/decay cross sections for the particles). The likelihood approach has become the most powerful tool, offering at least one well motivated method for incorporation of nuisance parameters and increasing the sensitivity of experiments by allowing a combination of targets superior to the more traditional data stacking. Other statistical challenges appearing in astrophysical searches are to large extent similar to any new physics search, for example at colliders, a prime example being the calculation of trial factors. Frequentist methods prevail for hypothesis testing and interval estimation, Bayesian methods are used for assessment of nuisance parameters and parameter estimation in complex parameter spaces. The basic statistical concepts will be exposed, illustrated with concrete examples from experimental searches and caveats will be pointed out.

  4. Hydro-biogeochemical Controls on Geophysical Signatures (Invited)

    NASA Astrophysics Data System (ADS)

    Atekwana, E. A.

    2013-12-01

    Geophysical techniques such as seismic, magnetic and electrical techniques have historically played a major role in oil exploration. Their main use has been for delineation basin geometry, structures and hydrocarbon traps and for understanding the subsurface stratigraphy. Their use for investigating microbial processes has only recently been recognized over the last decade resulting in the development of biogeophysics as a frontier research area which bridges the fields of environmental microbiology, biogeochemistry, geomicrobiology. Recent biogeophysical studies have demonstrated the potential of geophysical technologies to (1) probe the presence of microbial cells and biofilms in subsurface geologic media, (2) investigate the interactions between microorganisms and subsurface geologic media, (3) assess biogeochemical transformations, biomineralization, and biogeochemical reaction rates, and (4) investigate the alteration of physical properties of subsurface geologic media induced by microorganisms. The unique properties of geophysical datasets (e.g. non-invasive data acquisition, spatially continuous properties retrieved) make them attractive for probing microbial processes affecting fate and transport of contaminants. This presentation will provide an updated understanding of major controls on geophysical signatures by highlighting some of the important advancements in biogeophysical studies at hydrocarbon contaminated environments. Important challenges that provide an opportunity for further research in this new field will also be examined.

  5. Addressing the difficulty of changing fields in geophysics

    NASA Astrophysics Data System (ADS)

    Civilini, F.; Savage, M. K.

    2014-12-01

    Geophysics is a wonderfully diverse field of study, encompassing a variety of disciplines greatly different from one other. Even within the same discipline, various branches of study can have drastically different vocabulary and methodologies. The difficulty of breaking this "jargon" barrier is also an important reminder for scientists of how critical it is to clearly and concisely convey information. This presentation will focus on strategies that students can focus on to ease a transition between fields in geophysics. I believe that a student changing disciplines should proceed in the following steps: [1] Do a cursory literature review to find a review paper of the desired topic and work backwards through the details until a level of understanding or recognition is reached, [2] Obtain a clear physical understanding of the data and methods of the proposed study, and [3] Establish a support network through the research group or elsewhere which will recognize the areas in which the student is behind and offer remedies in a supportive and productive manner. These strategies are based on my own personal experience changing from music to geophysics in my undergrad and working on projects spanning various subdisciplines of geophysics during my Masters and PhD. It is worthwhile for research groups to spend the time to mentor students switching from other disciplines because those students will in time be able to observe the research in a different way than their peers, and easily adapt to changes of direction within the research.

  6. NASA Astrophysics Educator Ambassador Program

    NASA Astrophysics Data System (ADS)

    McLin, K. M.; Cominsky, L. R.

    2014-07-01

    The NASA Astrophysics Educator Ambassador (EA) Program began in 2001 as part of the GLAST (now Fermi) EPO effort at Sonoma State University. The program currently supports 15 EAs, sponsored by either Fermi (10), Swift (3), XMM-Newton (1) or NuSTAR (1). This group of master educators work with mission scientists and EPO personnel to develop curricula and train teachers; they also do workshops for students and outreach events with the general public. Every other year since 2002 the EAs assemble for a week of training at SSU. Each training has had a different focus. Additionally, time is given for the EAs to share ideas from their own workshops. In the dozen years of the program, the total number of teachers attending EA-run workshops is over 60,000, and EA workshops have received outstanding positive reviews from participants according to surveys conducted by our external evaluator, WestEd. This poster gives an overview of the program and its nationwide impact.

  7. Mass-23 nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    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 22Na puzzle of ONe white dwarf novae, where the abundance of 22Na 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 22Ne, a necessary step in studying the mass-23 nuclei mentioned above.

  8. Geological realism in hydrogeological and geophysical inverse modeling: A review

    NASA Astrophysics Data System (ADS)

    Linde, Niklas; Renard, Philippe; Mukerji, Tapan; Caers, Jef

    2015-12-01

    Scientific curiosity, exploration of georesources and environmental concerns are pushing the geoscientific research community toward subsurface investigations of ever-increasing complexity. This review explores various approaches to formulate and solve inverse problems in ways that effectively integrate geological concepts with geophysical and hydrogeological data. Modern geostatistical simulation algorithms can produce multiple subsurface realizations that are in agreement with conceptual geological models and statistical rock physics can be used to map these realizations into physical properties that are sensed by the geophysical or hydrogeological data. The inverse problem consists of finding one or an ensemble of such subsurface realizations that are in agreement with the data. The most general inversion frameworks are presently often computationally intractable when applied to large-scale problems and it is necessary to better understand the implications of simplifying (1) the conceptual geological model (e.g., using model compression); (2) the physical forward problem (e.g., using proxy models); and (3) the algorithm used to solve the inverse problem (e.g., Markov chain Monte Carlo or local optimization methods) to reach practical and robust solutions given today's computer resources and knowledge. We also highlight the need to not only use geophysical and hydrogeological data for parameter estimation purposes, but also to use them to falsify or corroborate alternative geological scenarios.

  9. Recent Efforts in Data Compilations for Nuclear Astrophysics

    SciTech Connect

    Dillmann, Iris

    2008-05-21

    Some recent efforts in compiling data for astrophysical purposes are introduced, which were discussed during a JINA-CARINA Collaboration meeting on 'Nuclear Physics Data Compilation for Nucleosynthesis Modeling' held at the ECT* in Trento/Italy from May 29th-June 3rd, 2007. The main goal of this collaboration is to develop an updated and unified nuclear reaction database for modeling a wide variety of stellar nucleosynthesis scenarios. Presently a large number of different reaction libraries (REACLIB) are used by the astrophysics community. The 'JINA Reaclib Database' on http://www.nscl.msu.edu/{approx}nero/db/ aims to merge and fit the latest experimental stellar cross sections and reaction rate data of various compilations, e.g. NACRE and its extension for Big Bang nucleosynthesis, Caughlan and Fowler, Iliadis et al., and KADoNiS.The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars, http://nuclear-astrophysics.fzk.de/kadonis) project is an online database for neutron capture cross sections relevant to the s process. The present version v0.2 is already included in a REACLIB file from Basel university (http://download.nucastro.org/astro/reaclib). The present status of experimental stellar (n,{gamma}) cross sections in KADoNiS is shown. It contains recommended cross sections for 355 isotopes between {sup 1}H and {sup 210}Bi, over 80% of them deduced from experimental data.A ''high priority list'' for measurements and evaluations for light charged-particle reactions set up by the JINA-CARINA collaboration is presented. The central web access point to submit and evaluate new data is provided by the Oak Ridge group via the http://www.nucastrodata.org homepage. 'Workflow tools' aim to make the evaluation process transparent and allow users to follow the progress.

  10. Recent Efforts in Data Compilations for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Dillmann, Iris

    2008-05-01

    Some recent efforts in compiling data for astrophysical purposes are introduced, which were discussed during a JINA-CARINA Collaboration meeting on ``Nuclear Physics Data Compilation for Nucleosynthesis Modeling'' held at the ECT* in Trento/Italy from May 29th-June 3rd, 2007. The main goal of this collaboration is to develop an updated and unified nuclear reaction database for modeling a wide variety of stellar nucleosynthesis scenarios. Presently a large number of different reaction libraries (REACLIB) are used by the astrophysics community. The ``JINA Reaclib Database'' on http://www.nscl.msu.edu/~nero/db/ aims to merge and fit the latest experimental stellar cross sections and reaction rate data of various compilations, e.g. NACRE and its extension for Big Bang nucleosynthesis, Caughlan and Fowler, Iliadis et al., and KADoNiS. The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars, http://nuclear-astrophysics.fzk.de/kadonis) project is an online database for neutron capture cross sections relevant to the s process. The present version v0.2 is already included in a REACLIB file from Basel university (http://download.nucastro.org/astro/reaclib). The present status of experimental stellar (n,γ) cross sections in KADoNiS is shown. It contains recommended cross sections for 355 isotopes between 1H and 210Bi, over 80% of them deduced from experimental data. A ``high priority list'' for measurements and evaluations for light charged-particle reactions set up by the JINA-CARINA collaboration is presented. The central web access point to submit and evaluate new data is provided by the Oak Ridge group via the http://www.nucastrodata.org homepage. ``Workflow tools'' aim to make the evaluation process transparent and allow users to follow the progress.

  11. High Energy Astrophysics Research and Programmatic Support

    NASA Technical Reports Server (NTRS)

    Angellini, L.

    1994-01-01

    This report reviews activities performed by members of the USRA contract team during the three months of the reporting period. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics.

  12. Building a Successful Teachers' Workshop in Astronomy & Astrophysics

    NASA Astrophysics Data System (ADS)

    Smecker-Hane, T. A.; Thornton, C. E.

    2005-12-01

    We discuss the Teachers' Workshop in Astronomy & Astrophysics, a 2-day long summer workshop we designed to aid K-12 grade teachers in incorporating astronomy and astrophysics into their curricula. These workshops are part of a faculty-led outreach program entitled Outreach in Astronomy & Astrophysics with the UCI Observatory, funded by an NSF FOCUS grant to the University of California, Irvine. Approximately 20 teachers from the Compton, Newport/Mesa and Santa Ana Unified School Districts attend each workshop. Our teachers realize that astronomy captures the imagination of their students, and thus lessons in astronomy can very effectively convey a number of challenging math and science concepts. Our workshop is designed to give teachers the content and instruction needed to achieve that goal. Because only a small fraction of teachers have taken a college astronomy course, an important component of the workshop is lectures on: (1) the motion of objects in the night sky, moon phases and the seasons, (2) the solar system, (3) the physics of light, and (4) interesting applications such as searching for planets around other stars and charting the expansion history of the Universe. The second important component of the workshop is the kit of material each teacher receives, which includes a introductory astronomy textbook, planetarium software, and the ASP's "Universe at Your Fingertips" and "More Universe at Your Fingertips", etc.. The latter two books give teachers many examples of creative hands-on activities and experiments they can do with their classes and instruction on how to build a coherent curriculum for their particular grade level. We also introduce teachers to Contemporary Laboratory Exercises in Astronomy (CLEA), a suite of computer lab exercises that can be used effectively in high school physics classes. For more information, see http://www.physics.uci.edu/%7Eobservat/#e&o. Funding provided by NSF grant EHR-0227202 (PI: Ronald Stern).

  13. Geophysical Model Applications for Monitoring

    SciTech Connect

    Pasyanos, M; Walter, W; Tkalcic, H; Franz, G; Gok, R; Rodgers, A

    2005-07-11

    Geophysical models constitute an important component of calibration for nuclear explosion monitoring. We will focus on four major topics and their applications: (1) surface wave models, (2) receiver function profiles, (3) regional tomography models, and (4) stochastic geophysical models. First, we continue to improve upon our surface wave model by adding more paths. This has allowed us to expand the region to all of Eurasia and into Africa, increase the resolution of our model, and extend results to even shorter periods (7 sec). High-resolution models exist for the Middle East and the YSKP region. The surface wave results can be inverted either alone, or in conjunction with other data, to derive models of the crust and upper mantle structure. One application of the group velocities is to construct phase-matched filters in combination with regional surface-wave magnitude formulas to improve the mb:Ms discriminant and extend it to smaller magnitude events. Next, we are using receiver functions, in joint inversions with the surface waves, to produce profiles directly under seismic stations throughout the region. In the past year, we have been focusing on deployments throughout the Middle East, including the Arabian Peninsula and Turkey. By assembling the results from many stations, we can see how regional seismic phases are affected by complicated upper mantle structure, including lithospheric thickness and anisotropy. The next geophysical model item, regional tomography models, can be used to predict regional travel times such as Pn and Sn. The times derived by the models can be used as a background model for empirical measurements or, where these don't exist, simply used as is. Finally, we have been exploring methodologies such as Markov Chain Monte Carlo (MCMC) to generate data-driven stochastic models. We have applied this technique to the YSKP region using surface wave dispersion data, body wave travel time data, receiver functions, and gravity data. The models

  14. Studies in geophysics: Active tectonics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  15. Molecular equilibrium with condensation. [in astrophysics

    NASA Technical Reports Server (NTRS)

    Sharp, C. M.; Huebner, W. F.

    1990-01-01

    Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated.

  16. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.

    1989-01-01

    Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.

  17. The data sharing advantage in astrophysics

    NASA Astrophysics Data System (ADS)

    Dorch, Bertil F.; Drachen, Thea M.; Ellegaard, Ole

    2016-10-01

    We present here evidence for the existence of a citation advantage within astrophysics for papers that link to data. Using simple measures based on publication data from NASA Astrophysics Data System we find a citation advantage for papers with links to data receiving on the average significantly more citations per paper than papers without links to data. Furthermore, using INSPEC and Web of Science databases we investigate whether either papers of an experimental or theoretical nature display different citation behavior.

  18. SNAP: An Astrophysical Camp That Flies High!

    NASA Astrophysics Data System (ADS)

    Forbes, D.; English, D.

    2010-08-01

    It has become widely recognized that there is a shortage of students coming out of provincial high schools who plan to pursue careers in scientific and technical fields. We aim to capture the interest and excite the imaginations of Grade 11 students in a three-day camp. The School for Nuclei, Astrophysics, and Particles (SNAP) will combine an introduction to astrophysics with the building and flying of a balloon-borne cosmic-ray detector to the very edge of space.

  19. Nuclear and Particle Astrophysics at CIPANP 2003

    NASA Astrophysics Data System (ADS)

    Baltz, Edward A.; Stone, James

    2004-02-01

    In the nuclear and particle astrophysics session of CIPANP 2003 we heard talks on a number of topics, focused for the most part into four broad areas. Here we outline the discussions of the standard cosmological model, dark matter searches, cosmic rays, and neutrino astrophysics. The robustness of theoretical and experimental programs in all of these areas is very encouraging, and we expect to have many questions answered, and new ones asked, in time for CIPANP 2006.

  20. Results and prospects in multi-messenger particle astrophysics

    NASA Astrophysics Data System (ADS)

    Mostafa, Miguel

    2017-01-01

    In high-energy particle astrophysics the old days were certainly not better than these. Our field has thrived in the past decade with experiments covering thousands of square kilometers to measure the suppression in the flux of the highest energy cosmic rays ever observed, instrumenting a cubic kilometer of Antarctic ice to discover astrophysical neutrinos, and measuring a change in arm length as small as 10-19 m for the ground-breaking direct observation of gravitational waves. Additionally, the current generation of space-borne and ground-based gamma-ray experiments have revealed a plethora of gamma-ray sources, including pulsars, compact binaries, the galactic center, and extragalactic sources such as starburst galaxies and radio galaxies. Before the next generation of instruments bring us yet another order of magnitude in sensitivity, we can combine current observations to probe physics beyond the standard model, and to extend the high-energy frontier well above the energies accessible to laboratory accelerators. One example of this potential is the search for dark-matter annihilation and decay products. To use the multi-messenger approach effectively for probing dark-matter signatures and physics beyond the LHC energy requires understanding the origin (or acceleration mechanism) and the propagation processes. High energy protons and nuclei, neutrinos, gamma-rays, X-rays, and gravitational waves bring new and complementary views of the astrophysical sources. By comparing observations through different windows, we can use the sites of violent phenomena as a laboratory to probe the physical processes under extreme conditions throughout the Universe, and to test the fundamental laws of particle physics and gravitation. As a community we need to engage in a bold synergistic approach to understanding the violent processes that give rise to the high-energy cosmic phenomena in the Universe. In this invited talk, I will present on-going multi-messenger studies to

  1. Geophysical Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

    Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.

    2007-01-01

    While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods

  2. Environmental and Engineering Geophysical University at SAGEEP 2008: Geophysical Instruction for Non-Geophysicists

    SciTech Connect

    Jeffrey G. Paine

    2009-03-13

    The Environmental and Engineering Geophysical Society (EEGS), a nonprofit professional organization, conducted an educational series of seminars at the Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP) in Philadelphia in April 2008. The purpose of these seminars, conducted under the name Environmental and Engineering Geophysical University (EEGU) over three days in parallel with the regular SAGEEP technical sessions, was to introduce nontraditional geophysical conference attendees to the appropriate use of geophysics in environmental and engineering projects. Five half-day, classroom-style sessions were led by recognized experts in the application of seismic, electrical, gravity, magnetics, and ground-penetrating radar methods. Classroom sessions were intended to educate regulators, environmental program managers, consultants, and students who are new to near-surface geophysics or are interested in learning how to incorporate appropriate geophysical approaches into characterization or remediation programs or evaluate the suitability of geophysical methods for general classes of environmental or engineering problems.

  3. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    SciTech Connect

    RUCKER DF; MYERS DA

    2011-10-04

    This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable of finding targets related to past releases, a loss of vertical resolution was the trade-off. The burying of electrodes below the infrastructure helped to increase the vertical resolution, as long as a sufficient number of electrodes are available for the acquisition campaign.

  4. Geophysical Methodologies for the Characterisation of Gas Hydrate Sediments

    NASA Astrophysics Data System (ADS)

    Lovell, M.; Jackson, P.; Gunn, D.; Rochelle, C.; Bateman, K.; Nelder, V.; Culshaw, M.; Rees, J.; Francis, T.; Roberts, J.; Schultheiss, P.

    2001-12-01

    The study of natural gas hydrate cores in the laboratory is currently limited by their instability at ambient conditions. Proposals to sample hydrates using pressure coring techniques and sample transfer chambers on-board ship are, however, in place and technical developments to enable these are well advanced (c.f. the HYACINTH project and ODP Leg 204). There is, however, a need to try to characterise the nature and extent of any gas hydrate within the pressurised sample prior to depressurising, opening and subsampling. The ability to geophysically characterise gas hydrates remotely while still in the pressurised core barrel may provide a route to detailing their physical extent and nature. With this objective, experiments to manufacture a range of synthetic gas hydrate morphologies in a range of sediments in the laboratory are in progress. To date we have succeeded in manufacturing a range of both pure and sediment-hosted CO2 hydrates. Continuing experiments are developing a range of geometrical and internal structures and fabrics (from massive to disseminated) using different sediment-hosts. These generic hydrate groups will provide a basis for non-invasive geophysical characterisation of hydrate morphologies. From these results protocols will be established to guide the geophysical logging of natural sediment-hydrate core maintained under pressure in lab transfer chambers on board the drillship, using the hyperbaric Geotek Core Logger. This will enable the characterisation and classification of hydrates sampled during ODP Leg 204 (and during subsequent hydrate sampling operations not restricted to ODP). While new insight will be gained into geophysical modelling of hydrate behaviour, it will also guide the development of sampling programs, prior to depressurising and initiating dissociation. This will allow detailed planning of shipboard scientific work utilising these rare and precious samples. This new knowledge will enhance geophysical survey data, better

  5. Software complex for geophysical data visualization

    NASA Astrophysics Data System (ADS)

    Kryukov, Ilya A.; Tyugin, Dmitry Y.; Kurkin, Andrey A.; Kurkina, Oxana E.

    2013-04-01

    The effectiveness of current research in geophysics is largely determined by the degree of implementation of the procedure of data processing and visualization with the use of modern information technology. Realistic and informative visualization of the results of three-dimensional modeling of geophysical processes contributes significantly into the naturalness of physical modeling and detailed view of the phenomena. The main difficulty in this case is to interpret the results of the calculations: it is necessary to be able to observe the various parameters of the three-dimensional models, build sections on different planes to evaluate certain characteristics and make a rapid assessment. Programs for interpretation and visualization of simulations are spread all over the world, for example, software systems such as ParaView, Golden Software Surfer, Voxler, Flow Vision and others. However, it is not always possible to solve the problem of visualization with the help of a single software package. Preprocessing, data transfer between the packages and setting up a uniform visualization style can turn into a long and routine work. In addition to this, sometimes special display modes for specific data are required and existing products tend to have more common features and are not always fully applicable to certain special cases. Rendering of dynamic data may require scripting languages that does not relieve the user from writing code. Therefore, the task was to develop a new and original software complex for the visualization of simulation results. Let us briefly list of the primary features that are developed. Software complex is a graphical application with a convenient and simple user interface that displays the results of the simulation. Complex is also able to interactively manage the image, resize the image without loss of quality, apply a two-dimensional and three-dimensional regular grid, set the coordinate axes with data labels and perform slice of data. The

  6. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

    2014-05-01

    In recent years geothermal heating and electricity generation have become an attractive alternative energy resource, especially natural high enthalpy geothermal systems such as in Iceland. However, the financial risk of installing and operating geothermal power plants is still high and more needs to be known about the geothermal processes and state of the reservoir in the subsurface. A powerful tool for probing the underground system structure is provided by geophysical techniques, which are able to detect flow paths and fracture systems without drilling. It has been amply demonstrated that small-scale features can be well imaged at shallow depths, but only gross structures can be delineated for depths of several kilometers, where most high enthalpy systems are located. Therefore a major goal of our study is to improve geophysical mapping strategies by multi-method geophysical simulations and synthetic data inversions, to better resolve structures at greater depth, characterize the reservoir and monitor any changes within it. The investigation forms part of project COTHERM - COmbined hydrological, geochemical and geophysical modeling of geoTHERMal systems - in which a holistic and synergistic approach is being adopted to achieve multidisciplinary cooperation and mutual benefit. The geophysical simulations are being performed in combination with hydrothermal fluid flow modeling and chemical fluid rock interaction modeling, to provide realistic constraints on lithology, pressure, temperature and fluid conditions of the subsurface. Two sites in Iceland have been selected for the study, Krafla and Reykjanes. As a starting point for the geophysical modeling, we seek to establish petrophysical relations, connecting rock properties and reservoir conditions with geophysical parameters such as seismic wave speed, attenuation, electrical conductivity and magnetic susceptibility with a main focus on seismic properties. Therefore, we follow a comprehensive approach involving

  7. New astrophysical probes of dark matter

    NASA Astrophysics Data System (ADS)

    Wang, Mei-Yu

    In my thesis, I present four studies to explore astrophysical methods for understanding dark matter properties. To understand the nature of dark matter, I explore a few unstable dark matter models that are invoked as ways to address apparent discrepancies between the predictions of standard cold dark matter and observations of small-scale galactic structure. My studies are aimed at developing independent large-scale constraints on these models. One of the model is a decaying dark matter model such that one dark matter particle decays into two relativistic non-interacting particles. In the second model, a dark matter particle decays into a less massive, stable dark matter particle with a recoil kick velocity Vk and a relativistic non-interacting particle. I consider two types of experiments: one is weak lensing cosmic shear with future or forthcoming surveys like Dark Energy Survey (DES) and Large Synoptic Survey Telescope (LSST); the other one is Lyman-alpha forest spectrum, which has contemporary data from Sloan Digital Sky Survey (SDSS) and other observations. I found that large-scale structure growth is sensitive to the change of dark matter properties due to these decay processes, and they can provide competitive constraints comparing to other existing limits. On small scale, the gravitational interplay of baryon and dark matter can affect the clustering of dark matter. I examine adiabatic contraction (AC) models what are traditionally used to parametrize the dark matter response to the cooling of baryons by investigating a suite of numerical simulations. We found that the errors in AC reconstructions are correlated with baryonic physics and certain halo properties. Our results indicate that existing AC models need significant calibration in order to predicting realistic matter distribution.

  8. Astroparticle physics

    NASA Astrophysics Data System (ADS)

    Ong, Rene A.

    2013-12-01

    Astroparticle physics is a rapidly developing field that has a high degree of overlap with particle physics and astronomy. This paper summarizes recent results and leading experiments in two selected areas: very high energy astrophysics and dark matter. Both areas have made great progress in the last 5 years due to improved instrumentation and a growing community. In very high energy astrophysics, many sources of GeV and TeV radiation have been detected and the challenge now is to fully understand the processes involved at these sites of extreme particle acceleration. In the area of dark matter, there is a close scientific connection between astroparticle experiments and the Large Hadron Collider (LHC). The combination of the LHC, direct-detection and indirect-detection experiments provide critical complementarity and unprecedented sensitivity in the quest to understand this deep mystery.

  9. Laboratory Plasma Source as an MHD Model for Astrophysical Jets

    NASA Technical Reports Server (NTRS)

    Mayo, Robert M.

    1997-01-01

    The significance of the work described herein lies in the demonstration of Magnetized Coaxial Plasma Gun (MCG) devices like CPS-1 to produce energetic laboratory magneto-flows with embedded magnetic fields that can be used as a simulation tool to study flow interaction dynamic of jet flows, to demonstrate the magnetic acceleration and collimation of flows with primarily toroidal fields, and study cross field transport in turbulent accreting flows. Since plasma produced in MCG devices have magnetic topology and MHD flow regime similarity to stellar and extragalactic jets, we expect that careful investigation of these flows in the laboratory will reveal fundamental physical mechanisms influencing astrophysical flows. Discussion in the next section (sec.2) focuses on recent results describing collimation, leading flow surface interaction layers, and turbulent accretion. The primary objectives for a new three year effort would involve the development and deployment of novel electrostatic, magnetic, and visible plasma diagnostic techniques to measure plasma and flow parameters of the CPS-1 device in the flow chamber downstream of the plasma source to study, (1) mass ejection, morphology, and collimation and stability of energetic outflows, (2) the effects of external magnetization on collimation and stability, (3) the interaction of such flows with background neutral gas, the generation of visible emission in such interaction, and effect of neutral clouds on jet flow dynamics, and (4) the cross magnetic field transport of turbulent accreting flows. The applicability of existing laboratory plasma facilities to the study of stellar and extragalactic plasma should be exploited to elucidate underlying physical mechanisms that cannot be ascertained though astrophysical observation, and provide baseline to a wide variety of proposed models, MHD and otherwise. The work proposed herin represents a continued effort on a novel approach in relating laboratory experiments to

  10. Numerical Relativity's Contributions to Theoretical Astrophysics, and Its Path Forward

    NASA Astrophysics Data System (ADS)

    Etienne, Zachariah

    2015-04-01

    In the extreme violence of merger and mass accretion, compact objects like black holes, neutron stars, and white dwarfs are thought to launch some of the most luminous outbursts of electromagnetic, neutrino, and gravitational wave energy in the Universe. Modeling these systems realistically remains a central problem in theoretical astrophysics, due to two key challenges. First, the emission mechanisms often stem from magnetized flows and dynamical gravitational fields spanning many orders of magnitude in lengthscale and timescale, from the strong-field region near compact objects, to the often magnetically-dominated, weak-field regions far away. Second, the equations governing the dynamics are highly complex and nonlinear, including the full general relativistic field equations as coupled to the equations of radiation general relativistic magnetohydrodynamics. I will review some of the current progress in developing numerical relativity codes that robustly and efficiently solve these equations (or some subset thereof) on non-uniform numerical grids to capture the multi-scale nature of compact object merger and mass accretion. Some key results from such codes will also be explored, providing examples of how numerical relativity has advanced theoretical astrophysics. Though these results are highly interesting, they often rely on extremely computationally expensive simulations that lack the accuracy and physical realism required for complete theoretical models. Thus, although numerical relativity simulations have begun to address key astrophysical questions, large gaps in our understanding remain. Bridging these gaps will require a continued focus on adding more physics to our simulations, as well as development of more computationally-efficient formulations of the equations and the algorithms for solving them.

  11. Simulated geophysical monitoring of radioactive waste repository barriers

    NASA Astrophysics Data System (ADS)

    Biryukov, Anton

    Estimation of attenuation of the elastic waves in clays and high clay-content rocks is important for the quality of geophysical methods relying on processing the recorded waveforms. Time-lapse imaging is planned to be employed for monitoring of the condition of high-radioactive waste repositories. Engineers can analyze and optimize configuration of the monitoring system using numerical modelling tools. The reliability of modeling requires proper calibration. The purpose of this thesis is threefold: (i) propose a calibration methodology for the wave propagation tools based on the experimental data, (ii) estimate the attenuation in bentonite as a function of temperature and water content, and (iii) investigate the feasibility of active sonic monitoring of the engineered barriers. The results suggest that pronounced inelastic behavior of bentonite has to be taken into account in geophysical modeling and analysis. The repository--scale models confirm that active sonic monitoring is capable of depicting physical changes in the bentonite barrier.

  12. Using Geophysical Signatures to Investigate Temporal Changes Due to Source Reduction in the Subsurface Contaminated with Hydrocarbons

    EPA Science Inventory

    We investigated the geophysical response to subsurface hydrocarbon contamination source removal. Source removal by natural attenuation or by engineered bioremediation is expected to change the biological, chemical, and physical environment associated with the contaminated matrix....

  13. Remote sensing-a geophysical perspective.

    USGS Publications Warehouse

    Watson, K.

    1985-01-01

    In this review of developments in the field of remote sensing from a geophysical perspective, the subject is limited to the electromagnetic spectrum from 0.4 mu m to 25cm. Three broad energy categories are covered: solar reflected, thermal infrared, and microwave.-from Authorremote sensing electromagnetic spectrum solar reflected thermal infrared microwave geophysics

  14. Successful educational geophysics field program expands

    NASA Astrophysics Data System (ADS)

    The Summer of Applied Geophysical Experience (SAGE), a program that gives students an opportunity to apply a variety of modern geophysical methods in a challenging geologic environment, has expanded.A 2-year grant awarded in 1993 by the National Science Foundation's Research Experiences for Undergraduate's (REU) initiative allowed the program to include fourteen U.S. undergraduate students last summer.

  15. Agricultural Geophysics: Past, present, and future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysical methods are becoming an increasingly valuable tool for agricultural applications. Agricultural geophysics investigations are commonly (although certainly not always) focused on delineating small- and/or large-scale objects/features within the soil profile (~ 0 to 2 m depth) over very lar...

  16. Strainmeters and tiltmeters in geophysics

    NASA Technical Reports Server (NTRS)

    Goulty, N. R.

    1976-01-01

    Several types of sensitive strainmeters and tiltmeters have been developed, and it is now becoming clear which geophysical applications are most suitable for these instruments. In general, strainmeters and tiltmeters are used for observing ground deformation at periods of minutes to days. Small-scale lateral inhomogeneities at the instrument sites distort signals by a few percent, although the effects of large structures can be calculated. In earth tide work these lateral inhomogeneities and unknown ocean loading signals prevent accurate values of the regional tide from being obtained. This limits tidal investigations to looking for temporal variations, possibly associated with pre-earthquake dilatancy, and spatial variations caused by gross elasticity contrasts in the local geological structure. Strainmeters and tiltmeters are well suited for observing long-period seismic waves, seismic slip events on faults and volcano tumescence, where small site-induced distortions in the measured signals are seldom important.

  17. Fractals in geology and geophysics

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1989-01-01

    The definition of a fractal distribution is that the number of objects N with a characteristic size greater than r scales with the relation N of about r exp -D. The frequency-size distributions for islands, earthquakes, fragments, ore deposits, and oil fields often satisfy this relation. This application illustrates a fundamental aspect of fractal distributions, scale invariance. The requirement of an object to define a scale in photograhs of many geological features is one indication of the wide applicability of scale invariance to geological problems; scale invariance can lead to fractal clustering. Geophysical spectra can also be related to fractals; these are self-affine fractals rather than self-similar fractals. Examples include the earth's topography and geoid.

  18. Goddard Geophysical and Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Figueroa, Ricardo

    2013-01-01

    This report summarizes the technical parameters and the technical staff of the VLBI system at the fundamental station GGAO. It also gives an overview about the VLBI activities during the report year. The Goddard Geophysical and Astronomical Observatory (GGAO) consists of a 5-meter radio telescope for VLBI, a new 12-meter radio telescope for VLBI2010 development, a 1-meter reference antenna for microwave holography development, an SLR site that includes MOBLAS-7, the NGSLR development system, and a 48" telescope for developmental two-color Satellite Laser Ranging, a GPS timing and development lab, a DORIS system, meteorological sensors, and a hydrogen maser. In addition, we are a fiducial IGS site with several IGS/IGSX receivers. GGAO is located on the east coast of the United States in Maryland. It is approximately 15 miles NNE of Washington, D.C. in Greenbelt, Maryland.

  19. Satellite Relaying of Geophysical Data

    NASA Technical Reports Server (NTRS)

    Allenby, R. J.

    1977-01-01

    Data Collection Platforms (DCPs) for transmitting surface data to an orbiting satellite for relaying to a central data distribution center are being used in a number of geophysical applications. "Off-the-shelf" DCP's, transmitting through Landsat or GOES satellites, are fully capable of relaying data from low-data-rate instruments, such as tiltmeters or tide gauges. In cooperation with the Lamont-Doherty Geological Observatory, Goddard has successfully installed DCP systems on a tide gauge and tiltmeter array on Anegada, British Virgin Islands. Because of the high-data-rate requirements, a practical relay system capable of handling seismic information is not yet available. Such a system could become the basis of an operational hazard prediction system for reducing losses due to major natural catastrophies such as earthquakes, volcanic eruptions, landslides or tsunamis.

  20. Using the Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, Alice; Teuben, P. J.; Berriman, G. B.; DuPrie, K.; Hanisch, R. J.; Mink, J. D.; Nemiroff, R. J.; Shamir, L.; Wallin, J. F.

    2013-01-01

    The Astrophysics Source Code Library (ASCL) is a free on-line registry of source codes that are of interest to astrophysicists; with over 500 codes, it is the largest collection of scientist-written astrophysics programs in existence. All ASCL source codes have been used to generate results published in or submitted to a refereed journal and are available either via a download site or from an identified source. An advisory committee formed in 2011 provides input and guides the development and expansion of the ASCL, and since January 2012, all accepted ASCL entries are indexed by ADS. Though software is increasingly important for the advancement of science in astrophysics, these methods are still often hidden from view or difficult to find. The ASCL (ascl.net/) seeks to improve the transparency and reproducibility of research by making these vital methods discoverable, and to provide recognition and incentive to those who write and release programs useful for astrophysics research. This poster provides a description of the ASCL, an update on recent additions, and the changes in the astrophysics community we are starting to see because of the ASCL.