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Sample records for physics astrophysics geophysics

  1. Direct Statistical Simulation of Astrophysical and Geophysical Flows

    NASA Astrophysics Data System (ADS)

    Marston, B.; Tobias, S.

    2011-12-01

    Astrophysical and geophysical flows are amenable to direct statistical simulation (DSS), the calculation of statistical properties that does not rely upon accumulation by direct numerical simulation (DNS) (Tobias and Marston, 2011). Anisotropic and inhomogeneous flows, such as those found in the atmospheres of planets, in rotating stars, and in disks, provide the starting point for an expansion in fluctuations about the mean flow, leading to a hierarchy of equations of motion for the equal-time cumulants. The method is described for a general set of evolution equations, and then illustrated for two specific cases: (i) A barotropic jet on a rotating sphere (Marston, Conover, and Schneider, 2008); and (ii) A model of a stellar tachocline driven by relaxation to an underlying flow with shear (Cally 2001) for which a joint instability arises from the combination of shearing forces and magnetic stress. The reliability of DSS is assessed by comparing statistics so obtained against those accumulated from DNS, the traditional approach. The simplest non-trivial closure, CE2, sets the third and higher cumulants to zero yet yields qualitatively accurate low-order statistics for both systems. Physically CE2 retains only the eddy-mean flow interaction, and drops the eddy-eddy interaction. Quantitatively accurate zonal means are found for barotropic jet for long and short (but not intermediate) relaxation times, and for Cally problem in the case of strong shearing and large magnetic fields. Deficiencies in CE2 can be repaired at the CE3 level, that is by retaining the third cumulant (Marston 2011). We conclude by discussing possible extensions of the method both in terms of computational methods and the range of astrophysical and geophysical problems that are of interest.

  2. Astrophysics and cosmic physics

    NASA Astrophysics Data System (ADS)

    Siuniaev, R. A.

    Recent astrophysical studies undertaken in the Soviet Union are surveyed. Papers are presented on the role of observations of galactic clusters in cosmological studies; photometric observations of active nuclei; investigations of the fine structure of radio sources; and interstellar molecules. Also considered are Type I supernovae, gamma-ray bursts, the motion of the sun in the interstellar medium, and astrophysical observations on Mt. Maidanak in Central Asia.

  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. Homologies in Physics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Bartlett, David F.; Cumalat, J. P.

    2012-01-01

    The genes of humans and chimpanzees are homologs. These genes are - in large measure - identical. From this detailed observation, we naturally suppose that both species evolved from a common ancestor. In particle physics the ordinary observed particles and their superymmetric partners are thought to be homologs, generated by a common "ancestor” , the Higgs particle. Experiments at CERN currently are testing this comfortable analogy of physics with biology. Neither the Higgs boson nor any supersymmetric particle has yet been found. We speculate that a variety of objects are homologs - evidence of an as yet undeveloped quantum theory of gravity to replace Dark Matter. A purely astronomical homology is the Vc - σ o relation which places nearly spherical elliptical galaxies just above well-formed spirals (SA & SB). Here the asymptotically- flat, circular velocity Vc is observed to be between 1 and 2 times the central bulge velocity dispersion σo over the range 60 km/s< σo <400 km/s (Ferrarese 2002, Fig 3). The Vc - σ o relation is difficult to explain with self-consistent equilibrium galaxy models (Courteau et al 2007). Here we give an explanation based on the Sinusoidal Potential, a non-Newtonian potential in which φ =-GM Cos[ko r]/r and ko=2 π /400 pc. We relate the lower limit of 60 km/s to the thermal velocity of protons at the” Broadhurst/Hirano & Hartnett” lookback redshift Z=105.6. This is the redshift where what was 400 pc then expands to 128 h-1 Mpc today. Further, at this Z the temperature of the universe was close to the Hartree Energy of 2 times 13.6 eV, an energy where protons have an rms speed of about 60 km/s.

  5. 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

  6. 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

  7. 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.

  8. GeoPhysical Analysis Code

    Energy Science and Technology Software Center (ESTSC)

    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 problemsmore » 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.« less

  9. GeoPhysical Analysis Code

    Energy Science and Technology Software Center (ESTSC)

    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. Themore » 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.« less

  10. 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.

  11. Mathematical Methods for Geophysics and Space Physics

    NASA Astrophysics Data System (ADS)

    Newman, William I.

    2016-05-01

    Graduate students in the natural sciences - including not only geophysics and space physics but also atmospheric and planetary physics, ocean sciences, and astronomy - need a broad-based mathematical toolbox to facilitate their research. In addition, they need to survey a wider array of mathematical methods that, while outside their particular areas of expertise, are important in related ones. While it is unrealistic to expect them to develop an encyclopedic knowledge of all the methods that are out there, they need to know how and where to obtain reliable and effective insights into these broader areas. Here at last is a graduate textbook that provides these students with the mathematical skills they need to succeed in today's highly interdisciplinary research environment. This authoritative and accessible book covers everything from the elements of vector and tensor analysis to ordinary differential equations, special functions, and chaos and fractals. Other topics include integral transforms, complex analysis, and inverse theory; partial differential equations of mathematical geophysics; probability, statistics, and computational methods; and much more. Proven in the classroom, Mathematical Methods for Geophysics and Space Physics features numerous exercises throughout as well as suggestions for further reading. * Provides an authoritative and accessible introduction to the subject * Covers vector and tensor analysis, ordinary differential equations, integrals and approximations, Fourier transforms, diffusion and dispersion, sound waves and perturbation theory, randomness in data, and a host of other topics * Features numerous exercises throughout * Ideal for students and researchers alike * An online illustration package is available to professors

  12. Cosmology, astrophysics and elementary particle physics

    NASA Astrophysics Data System (ADS)

    Tayler, R. J.

    1980-03-01

    The physics of the early universe are studied and the role of new particles such as heavy leptons, neutrinos and quarks and possible relationship of the net baryon number of the universe to unified models of elementary particle physics are discussed. Consideration is given to the role of neutrinos in stellar evolution, particularly in the explosion of supernovae and in the cooling of neutron stars. Black holes are discussed in connection with Hawking's discovery that low-mass black holes can emit a thermal distribution of particles which could be of cosmological or astrophysical importance. Finally, the evidence that the laws of physics are unchanging is examined, and it is concluded that there is no clear case in favor of change.

  13. 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

  14. 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

  15. 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.

  16. Nonlinear modal analysis of penetrative convection. [in stratified fluids under astrophysical and geophysical conditions

    NASA Technical Reports Server (NTRS)

    Zahn, J.-P.; Toomre, J.; Latour, J.

    1982-01-01

    It is pointed out that thermal convection in many astrophysical and geophysical settings occurs in an unstable layer bounded above and below by regions which are stably stratified. The convective motions may extend a substantial distance into the adjacent stable zones. If the motions have little direct effect upon the mean stratification of the stable zone, then they are usually referred to as convective overshooting. The primary objective of the present investigation is to study the dynamics of overshooting at very large Rayleigh numbers, mainly with stellar applications in mind. Numerically this is only feasible if severe simplifications are made in the description of what are likely to be turbulent motions. The approach employed in the investigation utilizes nonlinear modal equations in which the vertical and temporal structure of the convection is described accurately at the expense of the horizontal structure. A summary of the salient properties of penetrative convection is provided on the basis of the results of the conducted studies.

  17. Summary for astrophysics and non-accelerator physics

    SciTech Connect

    Kahana, S.H.

    1988-01-01

    This paper summarizes the presentations at the astrophysics and non-accelerator physics conference. Discussed in this paper are: supernovae, neutrinos, x-rays, gamma rays, cosmic rays, monopoles and primordial nucleosynthesis. 15 refs. (LSP)

  18. 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.

  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. 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.

  1. 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.

  2. 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.

  3. 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

  4. Nuclear physics reactions of astrophysical importance

    NASA Astrophysics Data System (ADS)

    O'Malley, Patrick D.

    2012-05-01

    Understanding the origin of elements in the universe is one of the main goals of nuclear science and astrophysics today. Achieving this goal involves determining how the elements and their isotopes formed and being able to predict their abundances. At the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL), an experimental program has been established to use transfer reactions (such as (p,d) or (d,p)) to study the properties of many nuclei important to understanding the origins of various elements. Three measurements were done to aid in the determination of the origins of different light isotopes. Big Bang Nucleosynthesis calculations, constrained by the Wilkinson Microwave Anisotropy Probe results, produce primordial 7Li abundances almost a factor of four larger than those extrapolated from observations. Since primordial 7Li is believed to be mostly produced by the beta decay of 7Be, one proposed solution to this discrepancy is a resonant enhancement of the 7Be(d, p)2α reaction rate through the 5/2+ 16.7-MeV state in 9B. The 2H(7Be,d) 7Be reaction was used to search for such a resonance; none was observed. An upper limit on the width of the proposed resonance was deduced. 19F is believed to have formed in Asymptotic Giant Branch stars, but current models cannot reproduce the observed abundances of this nucleus. One of the key reactions responsible for the creation of 19F is 15N(α,γ). Therefore, it is important to understand reactions that might destroy 15N, such as 15N(n,γ). The magnitude of the 15N( n,γ) reaction rate depends directly on the neutron spectroscopic factors of low-lying 16N levels. Currently the measured spectroscopic factors differ from those expected from theory by a factor of 2. A study has been done to resolve this discrepancy using the d( 15N,p) reaction. The spectroscopic factors were all found to be

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. Geophysical astrophysical spectral-element adaptive refinement (GASpAR): Object-oriented h-adaptive fluid dynamics simulation

    NASA Astrophysics Data System (ADS)

    Rosenberg, Duane; Fournier, Aimé; Fischer, Paul; Pouquet, Annick

    2006-06-01

    An object-oriented geophysical and astrophysical spectral-element adaptive refinement (GASpAR) code is introduced. Like most spectral-element codes, GASpAR combines finite-element efficiency with spectral-method accuracy. It is also designed to be flexible enough for a range of geophysics and astrophysics applications where turbulence or other complex multiscale problems arise. The formalism accommodates both conforming and non-conforming elements. Several aspects of this code derive from existing methods, but here are synthesized into a new formulation of dynamic adaptive refinement (DARe) of non-conforming h-type. As a demonstration of the code, several new 2D test cases are introduced that have time-dependent analytic solutions and exhibit localized flow features, including the 2D Burgers equation with straight, curved-radial and oblique-colliding fronts. These are proposed as standard test problems for comparable DARe codes. Quantitative errors are reported for 2D spatial and temporal convergence of DARe.

  10. 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.

  11. 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. PMID:26550862

  12. 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.

  13. 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.

  14. 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.

  15. Cosmic polarization rotation: An astrophysical test of fundamental physics

    NASA Astrophysics Data System (ADS)

    di Serego Alighieri, Sperello

    2015-02-01

    Possible violations of fundamental physical principles, e.g. the Einstein equivalence principle on which all metric theories of gravity are based, including general relativity (GR), would lead to a rotation of the plane of polarization for linearly polarized radiation traveling over cosmological distances, the so-called cosmic polarization rotation (CPR). We review here the astrophysical tests which have been carried out so far to check if CPR exists. These are using the radio and ultraviolet polarization of radio galaxies and the polarization of the cosmic microwave background (both E-mode and B-mode). These tests so far have been negative, leading to upper limits of the order of one degree on any CPR angle, thereby increasing our confidence in those physical principles, including GR. We also discuss future prospects in detecting CPR or improving the constraints on it.

  16. 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)

  17. PREFACE: NUBA Conference Series 1: Nuclear Physics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Boztosun, I.; Balantekin, A. B.; Kucuk, Y.

    2015-04-01

    The international conference series ''NUBA Conference Series 1: Nuclear Physics and Astrophysics'' was held on September 14-21 2014 in Antalya-Turkey. Akdeniz University hosted the conference and the Adrasan Training and Application Centre was chosen as a suitable venue to bring together scientists from all over the world as well as from different parts of Turkey. The conference was supported by the Scientific and Technological Research Council of Turkey (TÜBìTAK) and Akdeniz University Nuclear Sciences Application and Research Center (NUBA). Based on the highly positive remarks received from the participants both during and after the conference, we believe that the event has proven to be a fulfilling experience for all those who took part. The conference provided an opportunity for the participants to share their ideas and experiences in addition to exploring possibilities for future collaborations. Participants of the conference focused on: • Nuclear Structure and Interactions • Nuclear Reactions, • Photonuclear Reactions and Spectroscopy • Nuclear and Particle Astrophysics • Nuclear Processes in Early Universe • Nuclear Applications • New Facilities and Instrumentation Participants included a number of distinguished invited speakers. There was significant interest from the international nuclear physics community and numerous abstracts and papers were submitted. The scientific committee conducted a careful and rigorous selection process, as a result of which 75 contributions were accepted. Of those, 65 of them were given as oral and 10 as poster presentations. The superb quality of the papers ensured fruitful discussion sessions. We thank all the participants for their efforts and also for promptly sending in their papers for publication. This issue of the Journal of Physics: Conference Series was peer-reviewed by expert referees and we also thank them for peer-reviewing the papers. The national and international advisory committee also deserve

  18. 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.

  19. ASTRAL Code for Problems of Astrophysics and High Energy Density Physics

    NASA Astrophysics Data System (ADS)

    Chizhkova, N. E.; Ionov, G. V.; Karlykhanov, N. G.; Simonenko, V. A.

    2006-08-01

    The paper gives a brief description of ASTRAL code package for astrophysics simulations, including features in the implementation of basic physical processes and two tests. A sketch of the object code structure is provided.

  20. Geophysical and astrophysical turbulence

    NASA Astrophysics Data System (ADS)

    Moffatt, H. K.

    Spiral structures in two-dimensional turbulence are studied and a theory (Moffatt, 1985, 1986) which regards fully three-dimensional turbulence as an agglomeration of 'random vortex sheets and coherent helical structures' is reviewed. Consideration is given to the process by which current-sheet discontinuities may appear during magnetic relaxation. Within the framework of dynamo theory, the determination of the generation coefficient and the turbulent diffusivity in mean-field electrodynamics for turbulence with helicity in the limit of a large magnetic Reynolds number is discussed. Certain features of 'chromospheric turbulence' (i.e., turbulence in the solar atmosphere outside the photosphere) are also examined.

  1. 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

  2. Cosmological observations as a probe of fundamental physics and astrophysics

    NASA Astrophysics Data System (ADS)

    Ferraro, Simone

    The unifying theme of this dissertation is using cosmological observations as a tool to discover new physics and astrophysics. The first part focuses on the effects of primordial non-Gaussianity on the large-scale distribution of dark matter halos. The statistical properties of the primordial fluctuation contain a wealth of information about the Universe's early moments, and these properties are imprinted on the late-time distribution of matter. The first chapter serves as an introduction to the effects of non-Gaussianity on halo bias, summarizing previous work and extending it to the cubic local model (the gNL model). Chapter 2 generalizes some of the techniques of Chapter 1, allowing for the calculation of halo bias with arbitrary initial conditions, while Chapter 3 shows the relationship between the seemingly different techniques existing in the literature. Detailed forecasts for upcoming surveys are presented in Chapter 4, including the effect of marginalization over shot-noise and Gaussian part of the bias, photometric redshifts uncertainties and multi-tracer analysis to reduce the effect of cosmic variance. The second part contains work on two secondary anisotropies of the Cosmic Microwave Background radiation (CMB), namely the Integrated Sachs-Wolfe (ISW) effect and the kinetic Sunyaev-Zel'dovich (kSZ) effect. The late-time ISW effect arises because of decay of the large-scale gravitational potential due to the accelerated expansion and is therefore a powerful probe of dark energy. Chapter 5 presents a new detection of the ISW effect, using WISE galaxies and AGN as tracers of the gravitational potential, whose bias is measured in cross-correlation with CMB lensing maps. An appendix discusses the contamination of this measurement due to the linear part of the kSZ effect, the Doppler shift of photon energy due to scattering off coherently moving electrons. The last chapter explores the prospects of detecting the kSZ signal from sources for which accurate

  3. 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.

  4. The physics and theory of astrophysical neutrino sources

    NASA Astrophysics Data System (ADS)

    Fang, Ke

    2016-01-01

    The origin of astrophysical neutrinos remains a mystery. Absence of detection of EeV neutrinos questions, among other properties, the mass composition and the pion production efficiency of highest energy sources in the Universe. Growing statistics from the IceCube Observatory at TeV-PeV energies starts to reveal important features of the sources, including their energy spectrum, spacial distribution, emission rates, and Galactic/extragalactic origin. At sub-TeV, tensions exist between the fluxes of neutrinos and isotropic diffusive gamma-ray background, challenging some of the existing astrophysical and dark matter scenarios. In light of these observational constraints and implications, I will review a wide range of potential neutrino sources, focusing on their neutrino production mechanism and multi-messenger signatures.

  5. Nuclear physics experiments for the astrophysical p process

    NASA Astrophysics Data System (ADS)

    Sauerwein, A.; Elvers, M.; Endres, J.; Hasper, J.; Hennig, A.; Netterdon, L.; Zilges, A.

    2011-04-01

    We studied the two astrophysically interesting reactions 141PrPm and 92MoTc with the activation method and with the in-beam method, respectively. The 141PrPm experiment was performed at the cyclotron of the ‘Physikalisch Technische Bundesanstalt (PTB)’ in Braunschweig, Germany, and the reaction was studied within and just above the so-called Gamow window. In this proceedings, we present the experimental details of this measurement. The proton-capture reaction on the neutron-magic nucleus 92Mo was studied at energies relevant for the astrophysical p process. The reaction was investigated by the in-beam technique using the γ-ray detector array HORUS (High efficient Observatory for γ-Ray Unique Spectroscopy) at the TANDEM ion accelerator at the University of Cologne. The preliminary experimental results are compared to data stemming from other measurements.

  6. Topics in the physics and astrophysics of neutron stars

    NASA Astrophysics Data System (ADS)

    Postnikov, Sergey

    In this dissertation, four topics related to the physics and astrophysics of neutron stars are studied. Two first topics deal with microscopical physics processes in the star outer crust and the last two with macroscopical properties of a star, such as mass and radius. In the first topic, the thermodynamical and transport properties of a dilute gas in which particles interact through a delta-shell potential are investigated. Through variations of a single parameter related to the strength and size of the delta-shell potential, the scattering length and effective range that determine the low-energy elastic scattering cross sections can be varied over wide ranges including the case of the unitary limit (infinite scattering length). It is found that the coefficients of shear viscosity, thermal conductivity and diffusion all decrease when the scattering length becomes very large and also when resonances occur as the temperature is increased. The calculated ratios of the shear viscosity to entropy density as a function of temperature for various interaction strengths (and therefore scattering lengths) were found to lie well above the recently suggested minimal value of (4pi)-1h/kB. A new result is the value of (4/5) for the dimensionless ratio of the energy density times the diffusion coefficient to viscosity for a dilute gas in the unitary limit. Whether or not this ratio changes upon the inclusion of more than two-body interactions is an interesting avenue for future investigations. These investigations shed pedagogical light on the issue of the thermal and transport properties of an interacting system in the unitary limit, of much current interest in both atomic physics and nuclear physics in which very long scattering lengths feature prominently at very low energies. In the second topic, the shear viscosity of a Yukawa liquid, a model for the outer crust of a neutron star, is calculated in both the classical and quantum regimes. Results of semi-analytic calculations

  7. (?) The Air Force Geophysics Laboratory: Aeronomy, aerospace instrumentation, space physics, meteorology, terrestrial sciences and optical physics

    NASA Astrophysics Data System (ADS)

    McGinty, A. B.

    1982-04-01

    Contents: The Air Force Geophysics Laboratory; Aeronomy Division--Upper Atmosphere Composition, Middle Atmosphere Effects, Atmospheric UV Radiation, Satellite Accelerometer Density Measurement, Theoretical Density Studies, Chemical Transport Models, Turbulence and Forcing Functions, Atmospheric Ion Chemistry, Energy Budget Campaign, Kwajalein Reference Atmospheres, 1979, Satellite Studies of the Neutral Atmosphere, Satellite Studies of the Ionosphere, Aerospace Instrumentation Division--Sounding Rocket Program, Satellite Support, Rocket and Satellite Instrumentation; Space Physics Division--Solar Research, Solar Radio Research, Environmental Effects on Space Systems, Solar Proton Event Studies, Defense Meteorological Satellite Program, Ionospheric Effects Research, Spacecraft Charging Technology; Meteorology Division--Cloud Physics, Ground-Based Remote-Sensing Techniques, Mesoscale Observing and Forecasting, Design Climatology, Aircraft Icing Program, Atmospheric Dynamics; Terrestrial Sciences Division--Geodesy and Gravity, Geokinetics; Optical Physics Division--Atmospheric Transmission, Remote Sensing, INfrared Background; and Appendices.

  8. Research and career opportunities in the geophysical sciences for physics students

    NASA Astrophysics Data System (ADS)

    Nyblade, Andrew

    2008-10-01

    The field of geophysics involves using most branches of physics to investigate the physical structure and process that characterize the solid and fluid parts of our planet. Major advances in geophysics have come about from physicists crossing disciplinary boundaries and using their skills and knowledge to address first-order problems about the nature and structure of our planet and how the planet has changed over time. Indeed, some of the largest scientific breakthroughs in geophysics have come from physicists. As a way to introduce students to the field of geophysics and to provide them with information about research and career opportunities in geophysics, this talk will focus on one area of geophysics, seismology. This is an area of geophysics that has not only been instrumental in advancing our understanding of solid Earth structure and processes, but one that also has an applied side used for oil, gas and mineral exploration, as well as for environmental work. Examples of research projects involving seismic wave propagation and tomographic imaging will be presented, along the short descriptions of career opportunities in industry, government and academic institutions. In collaboration with Solomon Bililign, North Carolina A&T State University.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. A method for comparing non-nested models with application to astrophysical searches for new physics

    NASA Astrophysics Data System (ADS)

    Algeri, Sara; Conrad, Jan; van Dyk, David A.

    2016-05-01

    Searches for unknown physics and decisions between competing astrophysical models to explain data both rely on statistical hypothesis testing. The usual approach in searches for new physical phenomena is based on the statistical likelihood ratio test and its asymptotic properties. In the common situation, when neither of the two models under comparison is a special case of the other i.e. when the hypotheses are non-nested, this test is not applicable. In astrophysics, this problem occurs when two models that reside in different parameter spaces are to be compared. An important example is the recently reported excess emission in astrophysical γ-rays and the question whether its origin is known astrophysics or dark matter. We develop and study a new, simple, generally applicable, frequentist method and validate its statistical properties using a suite of simulations studies. We exemplify it on realistic simulated data of the Fermi-Large Area Telescope γ-ray satellite, where non-nested hypotheses testing appears in the search for particle dark matter.

  15. 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.

  16. Experimental Neutrino Physics and Astrophysics with the IMB-3 Detector

    NASA Astrophysics Data System (ADS)

    Casper, David William

    1990-01-01

    Description of the universe on the smallest (elementary particle physics) and largest (cosmology) scales has become dependent on the properties of the most weakly interacting fundamental particle known, the neutrino. The IMB experiment, designed to study nucleon decay, is also the world's largest detector of neutrinos. The experiment uses 6800 tons (3300 tons fiducial) of water as both target and detecting medium. Relativistic charges particles traversing the water radiate Cerenkov light. The distinctive ring patterns are imaged by 2048 light collectors (each a photo-multiplier tube coupled with a wavelength-shifting plate) distributed over the surfaces of the tank. This dissertation describes the IMB-3 detector, a four-fold increase in sensitivity over the original apparatus. Neutrino interactions of both atmospheric and extragalactic origin were collected during a 3.4 kiloton-year exposure. A consequence of non-zero neutrino mass could be oscillation of neutrino flavor. The energies and long flight distances of atmospheric neutrinos offer a unique opportunity to explore this possibility. To study the composition of the atmospheric neutrinos, single-ring events are classified as showering or non-showering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and a model of atmospheric neutrino production are used to predict the composition of the sample. The showering/non-showering character of an event is strongly correlated with the flavor of its neutrino parent. In the lepton momentum range p < 1500 MeV/c, non-showering events comprise 41 +/- 3(stat.) +/- 2(syst.)% of the total. The fraction expected is 51 +/- 5(syst.)%. Although this is evidence for an anomaly in the composition of atmospheric neutrinos, the 2sigma deviation is not sufficient to require neutrino oscillations. Eight interactions recorded over a six second interval on February 23, 1987 are coincident with the discovery of Supernova 1987a. These data, together with

  17. 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

  18. Trends in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Schatz, Hendrik

    2016-06-01

    Nuclear astrophysics is a vibrant field at the intersection of nuclear physics and astrophysics that encompasses research in nuclear physics, astrophysics, astronomy, and computational science. This paper is not a review. It is intended to provide an incomplete personal perspective on current trends in nuclear astrophysics and the specific role of nuclear physics in this field.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Li, Y. T.; Chen, L. M.; Dong, Q. L.; Zhong, J. Y.; Wang, W. M.; Sheng, Z. M.; Zhao, G.

    2016-05-01

    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.

  1. Positron astrophysics and areas of relation to low-energy positron physics

    NASA Astrophysics Data System (ADS)

    Guessoum, Nidhal

    2014-05-01

    I briefly review our general knowledge of positron astrophysics, focusing mostly on the theoretical and modelling aspects. The experimental/observational aspects of the topic have recently been reviewed elsewhere [E. Churazov et al., Mon. Nat. R. Astron. Soc. 411, 1727 (2011); N. Prantazos et al., Rev. Mod. Phys. 83, 1001 (2011)]. In particular, I highlight the interactions and cross sections of the reactions that the positrons undergo in various cosmic media. Indeed, these must be of high interest to both the positron astrophysics community and the low-energy positron physics community in trying to find common areas of potential collaboration for the future or areas of research that will help the astrophysics community make further progress on the problem. The processes undergone by positrons from the moments of their birth to their annihilation (in the interstellar medium or other locations) are thus examined. The physics of the positron interactions with gases and solids (dust grains) and the physical conditions and characteristics of the environments where the processes of energy loss, positronium formation, and annihilation take place, are briefly reviewed. An explanation is given about how all the relevant physical information is taken into account in order to calculate annihilation rates and spectra of the 511 keV emission in the ISM; special attention is paid to positron interactions with dust and with polycyclic aromatic hydrocarbons. In particular, an attempt is made to show to what extent the interactions between positrons and interstellar dust grains are similar to laboratory experiments in which beams of low-energy positrons impinge upon solids and surfaces. Sample results are shown for the effect of dust grains on positron annihilation spectra in some phases of the ISM which, together with high resolution spectra measured by satellites, can be used to infer useful knowledge about the environment where the annihilation is predominantly taking place

  2. J-PAS: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Dupke, Renato A.; Benitez, Narciso; Moles, Mariano; Sodre, Laerte; Irwin, Jimmy; J-PAS Collaboration

    2016-01-01

    The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Astrophysical Observatory in Spain with a dedicated 2.5m telescope and a 4.7deg^2 camera with 1.2Gpix. Starting in 2016, J-PAS will observe 8600 deg^2 of the Northern Sky and measure 0.003(1+z) precision photometric redshifts for nearly 1E08 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~14 Gpc^3 up to z = 1.3. J-PAS will also detect and measure the mass of more than a hundred thousand galaxy clusters, setting constrains on Dark Energy which rival those obtained from BAO measurements.The key to the J-PAS potential is its innovative approach the combination of 54 145°A filters, placed 100°A apart, and a multi-degree field of view (FOV) which makes it a powerful "redshift machine", with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. Moreover, since the J-PAS camera is equivalent to a very large, 4.7deg^2 "IFU", 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. J-PAS will have a lasting legacy value in many areas of Astrophysics, serving as a fundamental dataset for future Cosmological projects.Here, we present the overall description, status and scientific potential of the survey.

  3. J-PAS: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Dupke, Renato a.; Benitez, Narciso; Moles, Mariano; Sodre, Laerte; J-PAS Collaboration

    2015-08-01

    The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Astrophysical Observatory in Spain with a dedicated 2.5m telescope and a 4.7deg^2 camera with 1.2Gpix. Starting in 2016, J-PAS will observe 8600 deg^2 of the Northern Sky and measure 0.003(1+z) precision photometric redshifts for nearly 1E08 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~14 Gpc^3 up to z = 1.3. J-PAS will also detect and measure the mass of more than a hundred thousand galaxy clusters, setting constrains on Dark Energy which rival those obtained from BAO measurements.The key to the J-PAS potential is its innovative approach the combination of 54 145°A filters, placed 100°A apart, and a multi-degree field of view (FOV) which makes it a powerful “redshift machine”, with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. Moreover, since the J-PAS camera is equivalent to a very large, 4.7deg^2 “IFU”, 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. J-PAS will have a lasting legacy value in many areas of Astrophysics, serving as a fundamental dataset for future Cosmological projects.Here, we present the overall description, status and scientific potential of the survey.

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

    NASA Technical Reports Server (NTRS)

    Potter, A. E. (Editor); Wilson, T. L. (Editor)

    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.

  5. RNA as an Astrophysical or Geophysical Document?? Correlated issues in nebular and planetary astronomy, geology and biology

    NASA Astrophysics Data System (ADS)

    Hill, L. C.

    1999-12-01

    The emergence of the largely silicate earth from a presumably cosmically normal, H-rich solar nebula 4.5 eons ago is an obviously important issue relevant to many disciplines of the physical sciences. The emergence of terrestrial life is an equally important issue for biological sciences. Recent discoveries of isotopically light carbon (i.e. putative chemical fossils) in 3.85+ Ga Issua, Greenland sediments have reopened the issue of whether terrestrial life may have emerged prior to the earliest known rocks so that one might use biological records to deduce early terrestrial environments. In addition, recent advances in molecular genetics have suggested that all known ancestral life forms passed through an early hydrogen-rich environment which is more consistent with the now rejected Urey hypothesis of a early jovian atmosphere than with contemporary geological and planetological paradigms. In this essay, then, we examine possible limitations of contemporary paradigms of planetary science since a prima facie case will be made that life could not emerge in those environments which those paradigms now allow. Of necessity, the discussion will also address some hidden conflicts embedded in various disciplinary methodologies (e.g. astronomy, biology, geology).

  6. 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.

  7. Probing new physics with long-lived charged particles produced by atmospheric and astrophysical neutrinos

    SciTech Connect

    Ando, Shin'ichiro; Profumo, Stefano; Beacom, John F; Rainwater, David E-mail: beacom@mps.ohio-state.edu E-mail: rain@pas.rochester.edu

    2008-04-15

    As suggested by some extensions of the standard model of particle physics, dark matter may be a super-weakly-interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and metastable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins and analyze the dependence on the underlying particle physics set-up. We point out that, even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions and show that, for theoretically motivated and phenomenologically viable models, it is typically subdominant and below detectable rates.

  8. Probing new physics with long-lived charged particles produced by atmospheric and astrophysical neutrinos

    NASA Astrophysics Data System (ADS)

    Ando, Shin'ichiro; Beacom, John F.; Profumo, Stefano; Rainwater, David

    2008-04-01

    As suggested by some extensions of the standard model of particle physics, dark matter may be a super-weakly-interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and metastable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins and analyze the dependence on the underlying particle physics set-up. We point out that, even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions and show that, for theoretically motivated and phenomenologically viable models, it is typically subdominant and below detectable rates.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Particle Physics in the Sky and Astrophysics Underground: Connecting the Universe's Largest and Smallest Scales

    NASA Astrophysics Data System (ADS)

    Swanson, Molly E. C.

    2008-08-01

    Particles have tremendous potential as astronomical messengers, and conversely, studying the universe as a whole also teaches us about particle physics. This thesis encompasses both of these research directions. Many models predict a diffuse flux of high energy neutrinos from active galactic nuclei and other astrophysical sources. The "Astrophysics Underground" portion of this thesis describes a search for this neutrino flux performed by looking for very high energy upward-going muons using the Super-K detector. In addition to using particles to do astronomy, we can also use the universe itself as a particle physics lab. The "Particle Physics in the Sky" portion of this thesis focuses on extracting cosmological information from galaxy surveys. To overcome technical challenges faced by the latest galaxy surveys, we produced a comprehensive upgrade to mangle, a software package that processes the angular masks defining the survey area on the sky. We added dramatically faster algorithms and new useful features that are necessary for managing complex masks of current and next-generation galaxy surveys. With this software in hand, we utilized SDSS data to investigate the relation between galaxies and dark matter by studying relative bias, i.e., the relation between different types of galaxies. Separating galaxies by their luminosities and colors reveals a complicated picture: red galaxies are clustered more strongly than blue galaxies, with both the brightest and the faintest red galaxies showing the strongest clustering. Furthermore, red and blue galaxies tend to occupy different regions of space. In order to make precise measurements from the next generation of galaxy surveys, it will be essential to account for this complexity.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. Astrophysics, cosmology, and fundamental physics with compact binary coalescence and the Einstein Telescope

    NASA Astrophysics Data System (ADS)

    Van Den Broeck, C.

    2014-03-01

    The second-generation interferometric gravitational wave detectors, currently under construction are expected to make their first detections within this decade. This will firmly establish gravitational wave physics as an empirical science, and will open up a new era in astrophysics, cosmology, and fundamental physics. Already with the first detections, we will be able to, among other things, establish the nature of short-hard gamma ray bursts, definitively confirm the existence of black holes, measure the Hubble constant in a completely independent way, and for the first time gain access to the genuinely strong-field dynamics of gravity. Hence, it is time to consider the longer-term future of this new field. The Einstein Telescope (ET) is a concrete conceptual proposal for a third-generation gravitational wave observatory, which will be ~ 10 times more sensitive in strain than the second-generation detectors. This will give access to sources at cosmological distances, with a correspondingly higher detection rate. We have given an overview of the science case for ET, with a focus on what can be learned from signals emitted by coalescing compact binaries. Third-generation observatories will allow us to map the coalescence rate out to redshifts z ~ 3, determine the mass functions of neutron stars and black holes, and perform precision measurements of the neutron star equation of state. ET will enable us to study the large-scale structure and evolution of the Universe without recourse to a cosmic distance ladder. Finally, we have discussed how it will allow for high-precision measurements of strong-field, dynamical gravity.

  2. Reconciliation of statistical mechanics and astro-physical statistics: The errors of conventional canonical thermostatistics

    NASA Astrophysics Data System (ADS)

    Gross, Dieter H. E.

    2006-04-01

    Conventional thermo-statistics address infinite homogeneous systems within the canonical ensemble. (Only in this case, this is equivalent to the fundamental microcanonical ensemble.) However, some 170 years ago the original motivation of thermodynamics was the description of steam engines, i.e., boiling water. Its essential physics is the separation of the gas phase from the liquid. Of course, boiling water is inhomogeneous and as such cannot be treated by conventional thermo-statistics. Then it is not astonishing that a phase transition of first order is signaled canonically by a Yang Lee singularity. Thus it is only treated correctly by microcanonical Boltzmann Planck statistics. It turns out that the Boltzmann Planck statistics are much richer and give fundamental insight into statistical mechanics and especially into entropy. This can be done to a far extend rigorously and analytically. As no extensivity, no thermodynamic limit, no concavity, no homogeneity is needed, it also applies to astro-physical systems. The deep and essential difference between ‘extensive’ and ‘intensive’ control parameters, i.e., microcanonical and canonical statistics, is exemplified by rotating, self-gravitating systems. In the present article, the necessary appearance of a convex entropy S(E) and negative heat capacity at phase separation in small as well macroscopic systems independently of the range of the force is pointed out. Thus the old puzzle of stellar statistics is finally solved, the appearance of negative heat capacity which is forbidden and cannot appear in the canonical formalism. To cite this article: D.H.E. Gross, C. R. Physique 7 (2006).

  3. A physics-based emulator for the simulation of geophysical mass flows

    NASA Astrophysics Data System (ADS)

    Mahmood, Asif

    Rare natural hazards such as large volcanic eruptions can cause loss of life and damage to property. With sufficient information, those charged with public safety may issue warnings of impending hazards, to mitigate the hazard impact. Recent developments in modeling and simulating large geophysical mass flows can provide useful information in assessing hazard risk. These computer simulations of a system of partial differential equations are expensive to run, but analysis based on a few simulations is not sufficiently accurate for hazard analysis. Computational costs can be reduced by constructing a statistical emulator—a regression surface for selected output variables derived from several full simulator runs. Whenever the result from a simulation is required in an analysis, the emulator can be queried quickly. A key feature of the emulator is that an estimate of the prediction uncertainty, or error, is defined together with the regression estimate. A popular emulator is the Gaussian Process emulator, or GaSP, which is constructed as the mean of a Bayesian posterior distribution over input parameters. In this work, we propose an alternative procedure for constructing emulators, one that uses knowledge about the model physics. We model the mass flow as an Ornstein-Uhlenbeck (OU) process for sliding blocks along a surface, a stochastic extension of Newton's law of motion. We demonstrate how the OU results can be used to predict simulator results. A fit to the OU process is made, together with an error approximation, by classical statistical techniques.

  4. Particle astrophysics

    SciTech Connect

    Sadoulet, B. |

    1992-12-31

    In the last few years, particle astrophysics has emerged as a new field at the frontier between high energy astrophysics, cosmology, and particle physics. Two spectacular achievements of this new field in the last decade have been the establishment of neutrino astronomy with the detection of solar neutrinos by two independent experiments and the spectacular observation of the neutrinos from the supernova SN1987A. In addition, the field has produced tantalizing hints of new physics beyond the standard models of astrophysics and particle physics, generating enthusiastic attempts to confirm these potential effects. This new field involves some two hundred experimentalists and a similar number of theorists, most of them coming from particle and nuclear physics, and as scientist will see, their effort is to a large extent complementary to accelerator based high energy physics. This review attempts, at the beginning of this workshop, to capture the excitement of this new field. Summary talks will describe in more detail some of the topics discussed in the study groups.

  5. Parameterization of strombolian explosions: constraint from simultaneous physical and geophysical measurements (Invited)

    NASA Astrophysics Data System (ADS)

    gurioli, L.; Harris, A. J.

    2013-12-01

    Strombolian activity is the most common type of explosive eruption (by frequency) experienced by Earth's volcanoes. It is commonly viewed as consisting of a succession of short discrete explosions where fragments of incandescent magma are ejected a few tens to hundreds meters into the air. This kind of activity is generally restricted to basaltic or basaltic-andesitic magmas because these systems have the sufficiently low viscosities so as to allow gas coalescence and decoupled slug ascent. Mercalli (1907) proposed one of the first formal classifications of explosive activity based on the character of the erupted products and descriptions of case-type eruptions. Later, Walker (1973) devised a classification based on grain size and dispersion, within which strombolian explosions formed the low-to-middle end of the classification. Other classifications have categorized strombolian activity on the basis of erupted magnitude and/or intensity, such as Newhall and Self's (1982) Volcanic Explosivity Index (VEI). Classification can also be made on the basis of explosion mechanism, where strombolian eruptions have become associated with bursting of large gas bubbles, as opposed to release of locked in bubble populations in rapidly ascending magma that feed sustained fountains. Finally, strombolian eruptions can be defined on the basis of geophysical metrics for the explosion source and plume ascent dynamics. Recently, the volcanology community has begun to discuss the difficulty of actually placing strombolian explosions within the compartments defined by each scheme. New sampling strategies in active strombolian volcanic fields have allowed us to parameterize these mildly explosive events both physically and geophysically. Our data show that individual 'normal' and "major" explosions at Stromboli are extremely small, meaning that the classical deposit-based classification thresholds need to be reduced, or a new category defined, if the 'strombolian' eruption style at

  6. Challenges in astrophysics (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 25 January 2012)

    NASA Astrophysics Data System (ADS)

    2012-09-01

    On 25 January 2012, the scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS), entitled as "Challenges in astrophysics", was held at the conference hall of the Lebedev Physical Institute, RAS.The following reports were put on the session agenda posted on the website www.gpad.ac.ru of the RAS Physical Sciences Division: (1) Stepanov A V (Central (Pulkovo) Astronomical Observatory, RAS, St. Petersburg) "Coronal seismology";2) Yakovlev D G (Ioffe Physical Technical Institute, St. Petersburg St. Petersburg State Polytechnical University, St. Petersburg) "Superfluid neutron stars".The papers written on the base of the oral reports are published below. • Coronal seismology, A V Stepanov, V V Zaitsev, V M Nakariakov Physics-Uspekhi, 2012, Volume 55, Number 9, Pages 929-935 • Superfluid neutron stars, P S Shternin, D G Yakovlev Physics-Uspekhi, 2012, Volume 55, Number 9, Pages 935-941

  7. On the problems of relativistic laboratory astrophysics and fundamental physics with super powerful lasers

    SciTech Connect

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J.; Kondo, K.; Korn, G.

    2015-01-15

    The ways toward modeling of astrophysical processes and extreme field regimes with super-power lasers are discussed. The main attention is paid to the problem of limited similarity in using the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas. As the most typical examples, we address the magnetic reconnection and collisionless shock waves relevant to the problem of ultrarelativistic particle acceleration. In the extreme field limits we consider the regimes of dominant radiation reaction, changing the electromagnetic wave-matter interaction. In these regimes it, in particular, results in a new powerful source of ultra high-brightness gamma-rays and will make possible electron-positron pair creation in vacuum in a multiphoton processes. This will allow modeling under terrestrial laboratory conditions the processes in astrophysical objects and paves the way to experimental verifications using ultra intense lasers as they are currently developed within the ELI project.

  8. Atomic and molecular physics and data activities for astrophysics at Oak Ridge National Laboratory

    SciTech Connect

    Jeffery, D.J.; Kristic, P.S.; Liu, W.; Schultz, D.R.; Stancil, P.C.

    1998-04-01

    The atomic astrophysics group at ORNL produces, collects, evaluates, and disseminates atomic and molecular data relevant to astrophysics and actively models various astrophysical environments utilizing this information. With the advent of the World Wide Web, these data are also being placed on-line to facilitate their use by end-users. In this brief report, the group`s recent activities in data production and in modeling are highlighted. For example, the authors describe recent calculations of elastic and transport cross sections relevant to ionospheric and heliospheric studies, charge transfer between metal ions and metal atoms and novel supernova nebular spectra modeling, ion-molecule collision data relevant to planetary atmospheres and comets, and data for early universe modeling.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Astrophysical cosmology

    SciTech Connect

    Bardeen, J.M.

    1986-01-01

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

  20. 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.

  1. 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.

  2. Relevance of β-delayed neutron data for reactor, nuclear physics and astrophysics applications

    SciTech Connect

    Kratz, Karl-Ludwig

    2015-02-24

    Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (P{sub n}-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called 'Keepin groups' was generally accepted. Later, with the development of high-resolution neutron spectroscopy, βdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past three decades. This work has been recognized as an example of 'broad scientific diversity' which has led to my nomination for the 2014 Hans A. Bethe prize.

  3. Relevance of β-delayed neutron data for reactor, nuclear physics and astrophysics applications

    NASA Astrophysics Data System (ADS)

    Kratz, Karl-Ludwig

    2015-02-01

    Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (Pn-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called "Keepin groups" was generally accepted. Later, with the development of high-resolution neutron spectroscopy, βdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past three decades. This work has been recognized as an example of "broad scientific diversity" which has led to my nomination for the 2014 Hans A. Bethe prize.

  4. 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. PMID:23660558

  5. Workshop Summary: Fundamental Neutron Physics in the United States: An Opportunity in Nuclear, Particle, and Astrophysics for the Next Decade

    SciTech Connect

    Greene, G.

    2001-08-24

    Low-energy neutrons from reactor and spallation neutron sources have been employed in a wide variety of investigations that shed light on important issues in nuclear, particle, and astrophysics; in the elucidation of quantum mechanics; in the determination of fundamental constants; and in the study of fundamental symmetry violation (Appendix A, Glossary). In many cases, these experiments provide important information that is not otherwise available from accelerator-based nuclear physics facilities or high energy accelerators. An energetic research community in the United States is engaged in ''fundamental'' neutron physics. With exciting recent results, the possibility of new and upgraded sources, and a number of new experimental ideas, there is an important opportunity for outstanding science in the next decade. ''Fundamental'' neutron physics experiments are usually intensity limited. Researchers require the highest flux neutron sources available, which are either high-flux reactors (continuous sources) or spallation neutron sources (pulsed sources). The primary mission of these major facilities is neutron scattering for materials science research. Notwithstanding this condensed matter focus, essentially all neutron scattering facilities have accepted the value of an on-site fundamental physics program and have typically allocated 5 to 10% of their capabilities (i.e., beam lines) toward nuclear and particle physics research activities.

  6. Gravitational Radiation of a Vibrating Physical String as a Model for the Gravitational Emission of an Astrophysical Plasma

    NASA Astrophysics Data System (ADS)

    Lewis, Ray A.; Modanese, Giovanni

    Vibrating media offer an important testing ground for reconciling conflicts between General Relativity, Quantum Mechanics and other branches of physics. For sources like a Weber bar, the standard covariant formalism for elastic bodies can be applied. The vibrating string, however, is a source of gravitational waves which requires novel computational techniques, based on the explicit construction of a conserved and renormalized energy-momentum tensor. Renormalization (in a classical sense) is necessary to take into account the effect of external constraints, which affect the emission considerably. Our computation also relaxes usual simplifying assumptions like far-field approximation, spherical or plane wave symmetry, TT gauge and absence of internal interference. In a further step towards unification, the method is then adapted to give the radiation field of a transversal Alfven wave in a rarefied astrophysical plasma, where the tension is produced by an external static magnetic field.

  7. The Type Ia Supernova Pipeline for the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS)

    NASA Astrophysics Data System (ADS)

    Siffert, B. B.; Reis, R. R. R.; Calvão, M. O.

    2014-10-01

    The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is an astronomical facility being built in Sierra de Javalambre, Spain. The main goal is to study the expansion of the Universe through different cosmological observables such as baryonic acoustic oscillations, type Ia supernovae and galaxy clusters. The main instrument will be a 2.5 m telescope equipped with a system of 56 narrow band filters in the optical. Here we present a sketch of the pipeline we are developing to detect type Ia supernovae with J-PAS. First we describe each individual step of the pipeline, such as image subtraction and source selection. Then we show some results we obtained when applying our pipeline to images from the Sloan Digital Sky Survey and the ALHAMBRA survey, which had a set of narrow band filters similar to the ones that will be used by J-PAS.

  8. 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

  9. 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.

  10. Dust grains in a hot gas. I - Basic physics. II - Astrophysical applications

    NASA Technical Reports Server (NTRS)

    Burke, J. R.; Silk, J.

    1974-01-01

    The interaction of graphite grains with a hot gas is investigated. Detailed computations, based on experimental data and simple theoretical models are presented of the energy transfer by gas particle collisions and of the sputtering rates and grain lifetimes, as functions of gas temperature and grain radius. The electric charge on the grains is calculated, and the effect of electric forces on mechanical stability is discussed. The rate at which the gas cools by this mechanism is evaluated. The results of the work on gas-grain cooling and sputtering rates are applied to various astrophysical environments where dust and hot gas may coexist. The effect is studied of swept-up interstellar grains on the evolution of young supernova remnants, and the infrared luminosity is computed as a function of the age of the remnant. An interpretation is proposed of far-infrared sources embedded in compact H II regions or dense clouds, in terms of the supernova phenomenon, with specific application to eta Carinae. The question of the existence of dust in intergalactic matter in galaxy clusters is also reexamined.

  11. Atomic effects of beta decay in astrophysics and in elementary particle physics

    NASA Astrophysics Data System (ADS)

    Chen, Zonghua

    The bound-state beta decay of Re-187 and its application in Astrophysics is studied. There existed an uncertainty in the ratio of rhop of bound-state to continuum beta decay of Re-187 in both theory and experiment. A more definite theoretical result of rhop of approximately 1 percent is obtained by using single-configuration and multi-configuration Hartree-Fock-Dirac approximations. The results obtained are close to those obtained by Williams, Fowler, and Koonin by a modified Thomas-Fermi model. The bound-state beta decay of Re-187 at high temperatures is also studied. A generalization of the Thomas-Fermi results of various energy contributions to the ground-state energy of a neutral atom is also presented. An analytical expression for the ratio of the electron-electron to electron-nuclear interaction is obtained by the corrected Thomas-Fermi result, the ratio obtained gives a better agreement with the Hartree-Fock numerical results.

  12. Theoretical Astrophysics - Volume 1, Astrophysical Processes

    NASA Astrophysics Data System (ADS)

    Padmanabhan, T.

    2000-12-01

    Preface; 1. Order-of-magnitude astrophysics; 2. Dynamics; 3. Special relativity, electrodynamics and optics; 4. Basics of electromagnetic radiation; 5. Statistical mechanics; 6. Radiative processes; 7. Spectra; 8. Neutral fluids; 9. Plasma physics; 10. Gravitational dynamics; 11. General theory of relativity; 12. Basics of nuclear physics; Notes and References; Index.

  13. Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Mickaelian, A. M.; Astsatryan, H. V.

    2015-07-01

    Present astronomical archives that contain billions of objects, both Galactic and extragalactic, and the vast amount of data on them allow new studies and discoveries. Astrophysical Virtual Observatories (VO) use available databases and current observing material as a collection of interoperating data archives and software tools to form a research environment in which complex research programs can be conducted. Most of the modern databases give at present VO access to the stored information, which makes possible also a fast analysis and managing of these data. Cross-correlations result in revealing new objects and new samples. Very often dozens of thousands of sources hide a few very interesting ones that are needed to be discovered by comparison of various physical characteristics. VO is a prototype of Grid technologies that allows distributed data computation, analysis and imaging. Particularly important are data reduction and analysis systems: spectral analysis, SED building and fitting, modelling, variability studies, cross correlations, etc. Computational astrophysics has become an indissoluble part of astronomy and most of modern research is being done by means of it.

  14. 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.

  15. The s-process in meteoritic interstellar grains, a continuos interaction between Nuclear Physics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Gallino, R.; Kaeppeler, F.; Reifarth, R.; Straniero, O.; Cristallo, S.; Davis, A. M.; Dominguez, I.

    2003-04-01

    The results of s-process nucleosynthesis calculations for Asymptotic Giant Branch stars (AGB) of different initial mass and different metallicity are discussed in the framework of stellar evolutionary models using an updated network of neutron capture cross sections. They are applied to the astrophysical interpretation of the stellar origin of meteoritic interstellar SiC grains of different populations. The neutron production is driven by the 13C(α,n)16O reaction taking place in radiative conditions during the interpulse periods in a tiny layer (13C pocket) at the top of the He- and C-rich region. A second neutron exposure is released by the reaction 22Ne(α,n)25Mg during recurrent convective thermal pulses. This neutron source is marginal in low mass AGB stars. However, it affects the final distribution of isotopes involved in branching in the s-flow. The s-enriched material is subsequently mixed with the envelope according to the efficiency of the third dredge up, and then ejected in the interstellar medium by stellar winds. Noble gases are most likely implanted in the already formed SiC grains in the protoplanetary phase. We provide strong constraints for the Ne-E(H), Kr-S and Xe-S meteoritic components as compared with stellar models. With decreasing the initial metallicity, from solar to around 1/10 solar, the s-process abundance distribution in AGB stars first feeds the Zr-peak, then the Zr-peak is partly bypassed in favor of the Ba-peak (at metallicities around one third solar), eventually the s-process distribution is peaked at the double-magic nucleus 208Pb, at the termination point of the s-path. The predicted s-process isotopic composition of all elements is strongly dependent on the metallicity, especially for isotopes involved in branchings in the s-flow. This has important impacts in discriminating the origin of subclasses Y and Z SiC grains with future NANOSIMS OR CHARISMA measurements.

  16. Resources for Computational Geophysics Courses

    NASA Astrophysics Data System (ADS)

    Keers, Henk; Rondenay, Stéphane; Harlap, Yaël.; Nordmo, Ivar

    2014-09-01

    An important skill that students in solid Earth physics need to acquire is the ability to write computer programs that can be used for the processing, analysis, and modeling of geophysical data and phenomena. Therefore, this skill (which we call "computational geophysics") is a core part of any undergraduate geophysics curriculum. In this Forum, we share our personal experience in teaching such a course.

  17. 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.

  18. 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.

  19. 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.

  20. Arcetri Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Arcetri Astrophysical Observatory, a government research institute founded in 1972, is located close to the villa where Galileo spent the last 11 years of his life. Under the directorship of Giorgio Abetti (1921-53) it became the growth point of Italian astrophysics with emphasis on solar physics; a tradition continued by his successor Guglielmo Righini (1953-78). Since 1978 the activities ha...

  1. 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

  2. Integrated geophysical surveys on waste dumps: evaluation of physical parameters to characterize an urban waste dump (four case studies in Italy).

    PubMed

    Cardarelli, Ettore; Di Filippo, Gerardina

    2004-10-01

    Geophysical surveys were carried out on different waste dumps to evaluate key geometric and physical parameters. Depending on the dump dimensions and physical characteristics different geophysical techniques were used. Vertical electrical sounding, electrical resistivity tomography, induced polarization and seismic refraction techniques were integrated to eliminate the non-uniqueness of solutions and for a better understanding of the results. Physical parameters inside and outside the dumps were compared. The change of physical parameters such as resistivity, chargeability, and P-wave velocity allowed evaluation of waste dump geometry, leachate saturation levels, and thickness of waste. Furthermore, in illegal dumps, the size and waste type disposed could be evaluated. Calculated results were compared with plans and book-keeping from the dumps investigated. PMID:15560444

  3. The physical and infrared spectral properties of CO2 in astrophysical ice analogs

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.; Allamandola, L. J.

    1990-01-01

    Results of measurements of the infrared spectroscopic and condensation-vaporization properties of CO2 in pure and mixed ices are presented. Detailed examination of five infrared CO2 bands, 2.20, 2.78, 4.27, 15.2, and 4.39 microns, shows that the peak position, FWHM, and profile of the bands provide important information about the composition, formation, and subsequent thermal history of the ices. Absorption coefficients and their temperature dependence for all five CO2 bands are determined. The temperature dependence variation is found to be less than 15 percent from 10 to 150 K, i.e., the temperature at which H2O ice sublimes. The number of parameters associated with the physical behavior of CO2 in CO2- and H2O-rich ices, including surface binding energies, and condensation and sublimation temperatures, are determined under experimental conditions. The implications of the data obtained for cometary models are considered.

  4. 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.

  5. 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

  6. The physical and infrared spectral properties of CO2 in astrophysical ice analogs.

    PubMed

    Sandford, S A; Allamandola, L J

    1990-05-20

    Both laboratory measurements and theory indicate that CO2 should be a common component in interstellar ices. We show that the exact band position, width, and profile of the solid-state 12CO2 infrared bands near 3705, 3600, 2340, and 660 cm-1 (2.70, 2.78, 4.27, and 15.2 micrometers) and the 13CO2 band near 2280 cm-1 (4.39 micrometers) are dependent on the matrix in which the CO2 is frozen. Measurements of these bands in astronomical spectra can be used to determine column densities of solid-state CO2 and provide important information on the physical conditions present in the ice grains of which the CO2 is a part. Depending on the composition of the ice, the CO2 asymmetric stretching band was observed to vary from 2328.7 to 2346.0 cm-1 and have full widths at half-maxima (FWHMs) ranging from 4.7 to 29.9 cm-1. The other CO2 bands showed similar variations. Both position and width are also concentration dependent. Absorption coefficients were determined for the five CO2 bands. These were found to be temperature independent for CO2 in CO and CO2 matrices but varied slightly with temperature for CO2 in H2O-rich ices. For all five bands this variation was found to be less than 15% from 10 to 150 K, the temperature at which H2O ice sublimes. A number of parameters associated with the physical behavior of CO2 in CO2- and H2O-rich ices were also determined. The CO2-CO2 surface binding energy in pure CO2 ices is found to be (delta Hs/k) = 2690 +/- 50 K. CO2-H2O and CO-H2O surface binding energies were determined to be (delta Hs/k) = 2860 +/- 200 K and 1740 +/- 100 K, respectively. Under our experimental conditions, CO2 condenses in measurable quantities into H2O-rich ices at temperatures up to 100 K, only slightly higher than the temperature at which pure CO2 condenses. Once frozen into an H2O-rich ice, the subsequent loss of CO2 upon warming is highly dependent on concentration. For ices with H2O/CO2 > 20, the CO is physically trapped within the H2O lattice, and little CO2

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

    NASA Astrophysics Data System (ADS)

    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.; Cepa-Nogué, J.; Abramo, L. R.; Alcaniz, J. S.; Overzier, R.; Hernández-Monteagudo, C.; Alfaro, E. J.; Kanaan, A.; Carvano, M.; Reis, R. R. R.; J-PAS Collaboration

    2015-05-01

    J-PAS is a Spanish-Brazilian 8500 deg^2 Cosmological Survey which will be carried out from the Javalambre Observatory with a purpose-built, dedicated 2.5 m telescope and a 4.7 deg^2 camera with 1.2 Gpix. Starting in 2015, J-PAS will use 59 filters to measure high precision 0.003(1+z) photometric redshifts for 90M galaxies plus several million QSOs, about 50 times more than the largest current spectroscopic survey, sampling an effective volume of ˜ 14 Gpc^3 up to z=1.3. J-PAS will not only be first radial BAO experiment to reach Stage IV; it will also detect and measure the mass of 7× 10^5 galaxy clusters and groups, setting constrains on Dark Energy which rival those obtained from BAO measurements. The combination of a set of 145 Å NB filters, placed 100 Å apart, and a multi-degree field of view is a powerful ``redshift machine'', equivalent to a 4000 multiplexing spectrograph, but many times cheaper to build. The J-PAS camera is equivalent to a very large, 4.7 deg^2 ``IFU'', which will produce a time-resolved, 3D image of the Northern Sky with a very wide range of scientific applications in Galaxy Evolution, Stellar Physics and the Solar System.

  8. 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.

  9. 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. PMID:25968519

  10. 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

  11. 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.

  12. 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.

  13. 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.

  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. 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.

  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. Geophysical and physical measurements applied to characterize an area prone to quick clay landslides in SW Sweden

    NASA Astrophysics Data System (ADS)

    Salas-Romero, Silvia; Malehmir, Alireza; Snowball, Ian; Lougheed, Bryan C.; Hellqvist, Magnus

    2014-05-01

    The study of quick clay landslides in Nordic countries, such as Sweden and Norway, is wide and varied. However, the occurrence of catastrophes like those in Munkedal, Sweden, in 2006, demands a more complete characterization of these materials and their extensiveness. The objectives of this research are mainly focused on obtaining information about the properties and behavior of quick clays in an area prone to landslides in southwestern Sweden. Two fieldwork campaigns were carried out in 2011 and 2013, using methods such as 2D and 3D P-wave and S-wave seismic, geoelectrics, controlled-source and radio-magnetotellurics, ground gravity, as well as downhole geophysics (measuring fluid temperature and conductivity, gamma radiation, sonic velocity and resistivity) performed in three boreholes located in the study area. Drill cores recovered using the SONIC technique provided samples for paleontological information, as well as laboratory measurements of physical properties of the subsurface materials to a maximum subsurface depth of about 60 m. The laboratory measurements included grain size analysis, mineral magnetic properties, electric conductivity, pH, salinity, total dissolved solids, x-ray fluorescence (XRF), and a reconnaissance study of the fossil content. A correlation study of the downhole geophysical measurements, 2D seismic sections located at the intersection with the boreholes and the sample observations indicated that the presence of quick clays is associated with contacts with coarse-grained materials. Although the PVC casing of the boreholes interferes with the sonic and resistivity measurements, the perforated parts of the PVC casing show significant changes. The most important variations in magnetic susceptibility and conductivity mostly coincide with these coarse-grained layers, supporting the seismic data. Coarse-grained layers are characterized by enhanced magnetic susceptibility and conductivity. Grain size analysis results on subsamples from the

  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. 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...

  20. 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)

  1. 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)

  2. 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., III; 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Laboratory astrophysics

    SciTech Connect

    Springer, P.T.; Goldstein, W.H.; Iglesias, C.A.; Wilson, B.G.; Rogers, F.J.; Stewart, R.E.

    1995-05-01

    We propose an experiment to test opacity models for stellar atmospheres. Particularly important is to perform experiments at very low density and temperature where line shape treatments give large differences in Rosseland mean opacities for astrophysical mixtures, and to test the range of validity for the unresolved transition array treatments. Experimental requirements are ultra high spectral resolution combined with large homogenous plasma sources lasting tens of nanoseconds, and with Planckian radiation fields. These requirements dovetail nicely with emerging pulsed power capabilities. We propose a high resolution measurement of the frequency dependent opacity, for ultra low density iron plasmas in radiatively driven equilibrium plasmas.

  8. Highlights of Spanish Astrophysics VII

    NASA Astrophysics Data System (ADS)

    Guirado, J. C.; Lara, L. M.; Quilis, V.; Gorgas, J.

    2013-05-01

    "Highlights of Astronomy and Astrophysics VII" contains the Proceedings of the biannual meeting of the Spanish Astronomical Society held in Valencia from July 9 to 13, 2012. Over 300 astronomer, both national and international researchers, attended to the conference covering a wide variety of astrophysical topics: Galaxies and Cosmology, The Milky Way and Its Components, Planetary Sciences, Solar Physics, Instrumentation and Computation, and Teaching and Outreach of Astronomy.

  9. 16th Young Scientists' Conference on Astronomy and Space Physics

    NASA Astrophysics Data System (ADS)

    Choliy, V. Ya.; Ivashchenko, G.

    2009-12-01

    The present Proceedings of Contributed Papers include 23 papers presented during 16th Young Scientists' Conference on Astronomy and Space Physics which was held at the Faculty of Physics of National Taras Shevchenko University of Kyiv, from April 27 till May, 2, 2009. The aim of the annual Open Young Scientists' Conference on Astronomy and Space Physics is to provide young scientists a possibility to communicate and present their scientific work. The conference is intended for participation of students, PhD students and young researches who are involved in research in one of the following fields: positional astronomy and astronomical equipment, atmospheric studies and geophysics, plasma physics and physics of the near space, planetary systems and small bodies, solar physics and physics of heliosphere, stellar astrophysics, interstellar and intergalactic medium, extragalactic astrophysics, high-energy astrophysics, cosmology, computers in astronomy and related to the mentioned above.

  10. 15th Young Scientists' Conference on Astronomy and Space Physics

    NASA Astrophysics Data System (ADS)

    Choliy, V. Ya.; Ivashchenko, G.

    2008-12-01

    The present Proceedings of Contributed Papers include 19 papers presented during 15th Young Scientists' Conference on Astronomy and Space Physics which was held in Kyiv, at Kyiv National Taras Shevchenko University, Faculty of Physics, from April, 14 till April, 19, 2008. The aim of the annual Open Young Scientists' Conference on Astronomy and Space Physics is to provide young scientists a possibility to communicate and present their scientific work. The conference is intended for participation of students, PhD students and young researches who are involved in research in one of the following fields: astrometry and geophysics, plasma physics and physics of the near space, planetary systems, small bodies of the solar system, solar physics and physics of heliosphere, stellar astrophysics, interstellar medium, extragalactic astrophysics, high-energy astrophysics, cosmology, and related to the mentioned above.

  11. 14th Young Scientists Conference on Astronomy and Space Physics

    NASA Astrophysics Data System (ADS)

    Ivashchenko, G.; Golovin, A.

    2007-12-01

    The present Proceedings of Contributed Papers include 21 papers presented during 14th Young Scientists Conference on Astronomy and Space Physics which was held in Kyiv, at Kyiv National Taras Shevchenko University, Faculty of Physics, from April, 23 to April 28, 2007. The aim of the annual Open Young Scientists Conference on Astronomy and Space Physics is to provide young scientists a possibility to communicate and present their scientific work. The conference is intended for participation of students, PhD students and young researches who are involved in research in one of the following fields: astrometry and geophysics, plasma physics and physics of the near space, planetary systems, small bodies of the solar system, solar physics and physics of heliosphere, stellar astrophysics, interstellar medium, extragalactic astrophysics, high-energy astrophysics, cosmology, history of astronomy and related to the mentioned above.

  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. Nucleosynthesis and its implications on nuclear and particle physics; Proceedings of the NATO Advanced Research Workshop (Fifth Moriond Astrophysics Meeting), Les Arcs, France, March 17-23, 1985

    NASA Astrophysics Data System (ADS)

    Audouze, J.; Mathieu, N.

    The chemical composition of the universe is discussed in detail as a function of evolutionary and nucleosynthetic processes and astrophysical and laboratory observations. Consideration is given to recent theoretical work on primordial nucleosynthesis and the events occurring at atomic levels in explosive objects such as supernovae, WR stars and pancake stars. Attempts to understand s-process nucleosynthetic species production and production rates on the bases of observational data, theoretical models and laboratory studies are reported. The relative values of various nucleocosmochronometric isotopic pairs for assessing the age of the Galaxy are assessed, noting the role of WR stars in the production of short-lived isotopes such as Al-26. Various nuclear physics problems which are relevant to nucleosynthesis and cosmology are discussed and current attempts to detect neutrinos and monopoles are described.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Molecular astrophysics

    NASA Astrophysics Data System (ADS)

    Herzberg, G.

    1989-01-01

    A brief history of Molecular Astrophysics is presented. The first molecules in space were identified in the 1920s in comets followed soon after by those in planetary atmospheres. The recent identification by MCKELLAR of the dimer of H 2, that is, (H 2) 2 in the atmosphere of Jupiter as well as the discovery, by DROSSART, MAILLARD, WATSON and others, of the H 3+ ion in the auroral zone of Jupiter are described. In this laboratory there is a continuing interest in interstellar molecules. Several molecules and molecular ions were observed by collaboration of laboratory spectroscopists and astronomers. Only the most recent ones are discussed. Also a few of the molecules not yet observed but likely to be observed are mentioned.

  19. 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.

  20. 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

  1. The Tapestry of Modern Astrophysics

    NASA Astrophysics Data System (ADS)

    Shore, Steven N.

    2002-10-01

    The scope of modern astrophysics is the entire cosmos and everything in it. As and substantial as its subject, The Tapestry of Modern Astrophysics provides advanced undergraduates or graduate-level students with a comprehensive introduction to the subject. Avoiding axiomatic presentations, the author combines extensive qualitative discussions with analytical treatments so that students develop physical intuition the combination of observations and theoretical "horse sense" that is necessary for research in the field. The text is particularly distinguished by its deep and broad coverage, showing the way apparently different parts of astrophysics are intimately connected. Emphasizing the physical basis of the astrophysical phenomena along with the interpretation of data, Shore covers: The physical processes common to all cosmic bodies gravitation, thermal physics, and the gas laws. Special topics include statistical mechanics of stellar systems, rate equations, and General Relativity

  2. Overview of instrumentation and data analysis methods including calibration, instrumentation, and image formation and reconstruction Radiative transfer and physical processes in stellar and planetary atmospheres. Special topics include spectral classification and techniques for treating scattering Stellar structure and evolution, energy sources, and nucleosynthesis The interstellar medium with a general introduction to radiative and hydrodynamical processes The Milky Way as a galaxy, emphasizing the connection between locally observed phenomena and broader properties of extragalactic systems, active galaxies, and clusters of galaxies Cosmology and structure formation STEVEN N. SHORE is Professor of Physics and Astronomy at Indiana University South Bend. He is a scientific editor of the Astrophysical Journal and a visiting professor at Osservatorio Astrofisico di Arcetri, University of Pisa, University of Notre Dame, and Arizona State University. He is

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Fundamentals of Geophysics

    NASA Astrophysics Data System (ADS)

    Frohlich, Cliff

    Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

  8. Structure Formation in Astrophysics

    NASA Astrophysics Data System (ADS)

    Chabrier, Gilles

    2009-01-01

    Part I. Physical Processes and Numerical Methods Common to Structure Formations in Astrophysics: 1. The physics of turbulence E. Levêque; 2. The numerical simulation of turbulence W. Schmidt; 3. Numerical methods for radiation magnetohydrodynamics in astrophysics R. Klein and J. Stone; 4. The role of jets in the formation of planets, stars, and galaxies R. Banerjee, R. Pudritz and R. Ouyed; 5. Advanced numerical methods in astrophysical fluid dynamics A. Hujeirat and F. Heitsch; Part II. Structure and Star Formation in the Primordial Universe: 6. New frontiers in cosmology and galaxy formation challenges for the future R. Ellis and J. Silk; 7. Galaxy formation physics T. Abel, G. Bryan and R. Teyssier; 8. First stars formation, evolution, feedback effects V. Bromm, A. Ferrara and A. Heger; Part III. Contemporary Star and Brown Dwarf Formation: a) Cloud Formation and Fragmentation: 9. Diffuse interstellar medium and the formation of molecular clouds P. Hennebelle, M. Mac Low and E. Vazquez-Semadeni; 10. The formation of distributed and clustered stars in molecular clouds T. Megeath, Z. -Y. Li and A. Nordlund; b) Core Fragmentation and Star Formation: 11. The formation and evolution of prestellar cores P. André, S. Basu and S. Inutsuka; 12. Models for the formation of massive stars; Part IV. Protoplanetary Disks and Planet Formation M. Krumholz and I. Bonnell: 13. Observational properties of disks and young stellar objects G. Duchêne, F. Ménard, J. Muzzerolle and S. Mohanty; 14. Structure and dynamics of protoplanetary disks C. Dullemond, R. Durisen and J. Papaloizou; 15. Planet formation and evolution theory and observation Y. Alibert, I. Baraffe, W. Benz, G. Laughlin and S. Udry; 16. Planet formation assembling the puzzle G. Wurm and T. Guillot; Part V. Summary: 17. Open issues in small- and large-scale structure formation R. Klessen and M. Mac Low; 18. Final word E. Salpeter.

  9. Structure Formation in Astrophysics

    NASA Astrophysics Data System (ADS)

    Chabrier, Gilles

    2011-02-01

    Part I. Physical Processes and Numerical Methods Common to Structure Formations in Astrophysics: 1. The physics of turbulence E. Levêque; 2. The numerical simulation of turbulence W. Schmidt; 3. Numerical methods for radiation magnetohydrodynamics in astrophysics R. Klein and J. Stone; 4. The role of jets in the formation of planets, stars, and galaxies R. Banerjee, R. Pudritz and R. Ouyed; 5. Advanced numerical methods in astrophysical fluid dynamics A. Hujeirat and F. Heitsch; Part II. Structure and Star Formation in the Primordial Universe: 6. New frontiers in cosmology and galaxy formation challenges for the future R. Ellis and J. Silk; 7. Galaxy formation physics T. Abel, G. Bryan and R. Teyssier; 8. First stars formation, evolution, feedback effects V. Bromm, A. Ferrara and A. Heger; Part III. Contemporary Star and Brown Dwarf Formation: a) Cloud Formation and Fragmentation: 9. Diffuse interstellar medium and the formation of molecular clouds P. Hennebelle, M. Mac Low and E. Vazquez-Semadeni; 10. The formation of distributed and clustered stars in molecular clouds T. Megeath, Z. -Y. Li and A. Nordlund; b) Core Fragmentation and Star Formation: 11. The formation and evolution of prestellar cores P. André, S. Basu and S. Inutsuka; 12. Models for the formation of massive stars; Part IV. Protoplanetary Disks and Planet Formation M. Krumholz and I. Bonnell: 13. Observational properties of disks and young stellar objects G. Duchêne, F. Ménard, J. Muzzerolle and S. Mohanty; 14. Structure and dynamics of protoplanetary disks C. Dullemond, R. Durisen and J. Papaloizou; 15. Planet formation and evolution theory and observation Y. Alibert, I. Baraffe, W. Benz, G. Laughlin and S. Udry; 16. Planet formation assembling the puzzle G. Wurm and T. Guillot; Part V. Summary: 17. Open issues in small- and large-scale structure formation R. Klessen and M. Mac Low; 18. Final word E. Salpeter.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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…

  17. Astrophysical Bounds on Particle Properties

    NASA Astrophysics Data System (ADS)

    Raffelt, G.; Murdin, P.

    2000-11-01

    Ever since NEWTON proposed that the Moon on its orbit follows the same laws of motion as an apple falling from a tree, the heavens have been a favorite laboratory for testing the fundamental laws of physics, notably Newton's and EINSTEIN's theories of gravity. More recently, astrophysics and cosmology have become crucial testing grounds for the microcosm of elementary particles. This area of scie...

  18. 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…

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

    SciTech Connect

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

    2011-11-14

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

  20. 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

  21. Planetary rings and astrophysical discs

    NASA Astrophysics Data System (ADS)

    Latter, Henrik

    2016-05-01

    Disks are ubiquitous in astrophysics and participate in some of its most important processes. Of special interest is their role in star, planet and moon formation, the growth of supermassive black holes, and the launching of jets. Although astrophysical disks can be up to ten orders of magnitude larger than planetary rings and differ hugely in composition, all disks share to some extent the same basic dynamics and many physical phenomena. This review explores these areas of overlap. Topics covered include disk formation, accretion, collisions, instabilities, and satellite-disk interactions.

  1. Heavy elements in astrophysical nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Sun, Bao-Hua; Niu, Zhong-Ming

    With the many successes of covariant density functional theory (CDFT) as seen in the previous chapters, there has been growing interest over the last years to examine directly their applicability in astrophysical nucleosynthesis simulations. This chapter thus concentrates on the very recent applications of CDFT in astrophysics nucleosynthesis, ranging from the calculations of nuclear physics inputs -- masses and beta-decay half-lives -- for rapid-neutron (r-) and rapid-proton (rp-) capture processes, to the nucleosynthesis studies that employed these inputs and to nuclear cosmochronology. The concepts of nucleosynthesis process and formulas on beta-decays are sketched briefly.

  2. Astrophysics. A primer

    NASA Astrophysics Data System (ADS)

    Kundt, Wolfgang

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

  3. 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

  4. Nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2010-08-01

    The International Year of Astronomy 2009 (IYA2009) was declared by the 62nd General Assembly of the United Nations and was also endorsed by UNESCO. Investigations in the realms of particle and nuclear physicsmake a large contribution in the development of our ideas of the properties of the Universe. The present article discusses some problems of the evolution of the Universe, nucleosyntheses, and cosmochronology from the point of view of nuclear and particle physics. Processes occurring in the Universe are compared with the mechanisms of the production and decay of nuclei, as well as with the mechanisms of their interaction at high energies. Examples that demonstrate the potential of nuclearphysics methods for studying cosmic objects and the properties of the Universe are given. The results that come from investigations into nuclear reactions induced by beams of radioactive nuclei and which make it possible to take a fresh look at the nucleosynthesis scenario in the range at light nuclei are presented.

  5. 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.

  6. Handbook of Space Astronomy and Astrophysics

    NASA Astrophysics Data System (ADS)

    Zombeck, Martin V.

    2006-11-01

    Foreword; Preface; 1. General data; 2. Astronomy and astrophysics; 3. Radio astronomy; 4. Infrared and submillimeter astronomy; 5. Ultraviolet astronomy; 6. X-ray astronomy; 7. Gamma-ray astronomy; 8. Cosmic rays; 9. Earth's atmosphere and environment; 10. Relativity and cosmology; 11. Atomic physics; 12. Electromagnetic radiation; 13. Plamsa physics; 14. Experimental astronomy and astrophysics; 15. Astronautics; 16. Mathematics; 17. Probability and statistics; 18. Radiation safety; 19. Astronomical catalogs; 20. Computer science; 21. Glossary of abbreviations and symbols; Appendices; Index.

  7. Demonstrations in Introductory Geophysics

    NASA Astrophysics Data System (ADS)

    Schramm, K. A.; Stein, S.; van der Lee, S.; Swafford, L.; Klosko, E.; Delaughter, J.; Wysession, M.

    2005-12-01

    Geophysical concepts are challenging to teach at introductory levels, because students need to understand both the underlying physics and its geological application. To address this, our introductory courses include class demonstrations and experiments to demonstrate underlying physical principles and their geological applications. Demonstrations and experiments have several advantages over computer simulations. First, computer simulations "work" even if the basic principle is wrong. In contrast, simple demonstrations show that a principle is physically correct, rather than a product of computer graphics. Second, many students are unfamiliar with once-standard experiments demonstrating ideas of classical physics used in geophysics. Demonstrations are chosen that we consider stimulating, relevant, inexpensive, and easy to conduct in a non-lab classroom. These come in several groups. Many deal with aspects of seismic waves, using springs, light beams, and other methods such as talking from outside the room to illustrate the frequency dependence of diffraction (hearing but not seeing around a corner). Others deal with heat and mass transfer, such as illustrating fractional crystallization with apple juice and the surface/volume effect in planetary evolution with ice. Plate motions are illustrated with paper cutouts showing effects like motion on transform faults and how the Euler vector geometry changes a plate boundary from spreading, to strike-slip, to convergence along the Pacific-North America boundary from the Gulf of California to Alaska. Radioactive decay is simulated by having the class rise and sit down as a result of coin flips (one tail versus two gives different decay rates and hence half lives). This sessions' goal of exchanging information about demonstrations is an excellent idea: some of ours are described on http://www.earth.nwu.edu/people/seth/202.

  8. Relativistic astrophysics explorer

    NASA Astrophysics Data System (ADS)

    Kaaret, P.

    2004-01-01

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 6 m 2 equal to 10 times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  9. The Relativistic Astrophysics Explorer

    NASA Astrophysics Data System (ADS)

    Kaaret, P.

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 60,000 cm2 equal to ten times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  10. 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:

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Radiative Magnetic Reconnection in Astrophysics

    NASA Astrophysics Data System (ADS)

    Uzdensky, D. A.

    In this chapter we review a new and rapidly growing area of research in high-energy plasma astrophysics—radiative magnetic reconnection, defined here as a regime of reconnection where radiation reaction has an important influence on the reconnection dynamics, energetics, and/or nonthermal particle acceleration. This influence be may be manifested via a variety of radiative effects that are critical in many high-energy astrophysical applications. The most notable radiative effects in astrophysical reconnection include radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. The self-consistent inclusion of these effects into magnetic reconnection theory and modeling sometimes calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool available for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical conditions in a reconnecting system to observable radiative signatures. This chapter presents an overview of our recent theoretical progress in developing basic physical understanding of radiative magnetic reconnection, with a special emphasis on astrophysically most important radiation mechanisms like synchrotron, curvature, and inverse-Compton. The chapter also offers a broad review of key high-energy astrophysical applications of radiative reconnection, illustrated by multiple examples such as: pulsar wind nebulae, pulsar magnetospheres, black-hole accretion-disk coronae and hot accretion flows in X-ray Binaries and Active Galactic Nuclei and their relativistic jets, magnetospheres of magnetars, and Gamma-Ray Bursts. Finally, this chapter discusses the most critical

  19. 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...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Revised physical elements of the astrophysically important O9.5+O9.5V eclipsing binary system Y Cygni

    NASA Astrophysics Data System (ADS)

    Harmanec, P.; Holmgren, D. E.; Wolf, M.; Božić, H.; Guinan, E. F.; Kang, Y. W.; Mayer, P.; McCook, G. P.; Nemravová, J.; Yang, S.; Šlechta, M.; Ruždjak, D.; Sudar, D.; Svoboda, P.

    2014-03-01

    Context. Rapid advancements in light-curve and radial-velocity curve modelling, as well as improvements in the accuracy of observations, allow more stringent tests of the theory of stellar evolution. Binaries with rapid apsidal advance are particularly useful in this respect since the internal structure of the stars can also be tested. Aims: Thanks to its long and rich observational history and rapid apsidal motion, the massive eclipsing binary Y Cygrepresents one of the cornerstones of critical tests of stellar evolutionary theory for massive stars. Nevertheless, the determination of the basic physical properties is less accurate than it could be given the existing number of spectral and photometric observations. Our goal is to analyse all these data simultaneously with the new dedicated series of our own spectral and photometric observations from observatories widely separated in longitude. Methods: We obtained new series of UBV observations at three observatories separated in local time to obtain complete light curves of Y Cygfor its orbital period close to 3 days. This new photometry was reduced and carefully transformed to the standard UBV system using the HEC22 program. We also obtained new series of red spectra secured at two observatories and re-analysed earlier obtained blue electronic spectra. Reduction of the new spectra was carried out in the IRAF and SPEFO programs. Orbital elements were derived independently with the FOTEL and PHOEBE programs and via disentangling with the program KOREL . The final combined solution was obtained with the program PHOEBE . Results: Our analyses provide the most accurate value of the apsidal period of (47.805 ± 0.030) yr published so far and the following physical elements: M1 = 17.72 ± 0.35 M⊙, M2 = 17.73 ± 0.30 M⊙, R1 = 5.785 ± 0.091 R⊙, and R2 = 5.816 ± 0.063 R⊙. The disentangling thus resulted in the masses, which are somewhat higher than all previous determinations and virtually the same for both stars

  10. Relativistic jets in astrophysics

    NASA Astrophysics Data System (ADS)

    Derishev, E. V.; Zheleznyakov, V. V.; Koryagin, S. A.; Kocharovsky, Vl. V.

    The properties of the plasma state of matter are determined by the motion and the electromagnetic emission of the non-bound electrically charged particles --- electrons, positrons, protons and ions. It is not easy to create plasma in a laboratory. However this state is typical for the cosmic conditions --- at the stars and in the interstellar space. The properties of the laboratory as well as the space plasma are investigated at the Institute of Applied Physics of the Russian Academy of Sciences. The research is focused on the mechanisms of generation and propagation of the electromagnetic radiation --- from the radio waves to the gamma-rays --- in the planetary and stellar atmospheres and at the other astrophysical objects. The extreme physical conditions for a plasma are realized near the compact objects like black holes, neutron stars and collapsing nuclei of the massive stars. The plasma could be strongly non-equlibrium and can produce strong electromagnetic fields. Its bulk motion as well as the chaotic motion of the constituting particles can be relativistic, i. e. the motion can achieve velocities close to the speed of light. The relativistic plasma is frequently observed in the form of jets.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Handbook of space astronomy and astrophysics

    NASA Astrophysics Data System (ADS)

    Zombeck, Martin V.

    Tables, graphs, maps, diagrams, and formulas summarizing data and illustrating relationships of interest to space astronomers and astrophysicists are complied in handbook form. General data such as physical and solar-system constants, cosmological parameters, unit conversions, numerical constants, mathematical formulas, and symbols are given in a preliminary section. Individual chapters are devoted to astronomy (A) and astrophysics, radio A, IR A, UV A, X-ray A, gamma-ray A, cosmic rays, earth atmosphere and environment, relativity, atomic physics, electromagnetic radiation, plasma physics, experimental astrophysics, aeronautics and astronautics, mathematics, statistics, radiation safety, and astronomical catalogs.

  16. Astrophysical Institute, Potsdam

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

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

  17. Physics through the 1990s: plasmas and fluids

    SciTech Connect

    Not Available

    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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Underground nuclear astrophysics: Why and how

    NASA Astrophysics Data System (ADS)

    Best, A.; Caciolli, A.; Fülöp, Zs.; Gyürky, Gy.; Laubenstein, M.; Napolitani, E.; Rigato, V.; Roca, V.; Szücs, T.

    2016-04-01

    The goal of nuclear astrophysics is to measure cross-sections of nuclear physics reactions of interest in astrophysics. At stars temperatures, these cross-sections are very low due to the suppression of the Coulomb barrier. Cosmic-ray-induced background can seriously limit the determination of reaction cross-sections at energies relevant to astrophysical processes and experimental setups should be arranged in order to improve the signal-to-noise ratio. Placing experiments in underground sites, however, reduces this background opening the way towards ultra low cross-section determination. LUNA (Laboratory for Underground Nuclear Astrophysics) was pioneer in this sense. Two accelerators were mounted at the INFN National Laboratories of Gran Sasso (LNGS) allowing to study nuclear reactions close to stellar energies. A summary of the relevant technology used, including accelerators, target production and characterisation, and background treatment is given.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. News and Views: Challenges of Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Opher, Reuven

    2013-12-01

    I discuss some of the most outstanding challenges in relativistic astrophysics in the subjects of compact objects (black holes and neutron stars), dark sector (dark matter and dark energy), plasma astrophysics (origin of jets, cosmic rays, and magnetic fields), and the primordial universe (physics at the beginning of the Universe). In these four subjects, I discuss 12 of the most important challenges. These challenges give us insight into new physics that can only be studied in the large scale universe. The near-future possibilities, in observations and theory, for addressing these challenges are also discussed.

  8. Geophysical monitoring using 3D joint inversion of multi-modal geophysical data with Gramian constraints

    NASA Astrophysics Data System (ADS)

    Zhdanov, M. S.; Gribenko, A.; Wilson, G. A.

    2012-12-01

    Geophysical monitoring of reservoir fluids and rock properties is relevant to oil and gas production, carbon sequestration, and enhanced geothermal systems. Different geophysical fields provide information about different physical properties of the earth. Multiple geophysical surveys spanning gravity, magnetic, electromagnetic, seismic, and thermal methods are often interpreted to infer geology from models of different physical properties. In many cases, the various geophysical data are complimentary, making it natural to consider a formal mathematical framework for their joint inversion to a shared earth model. We introduce a new approach to the 3D joint inversion of multiple geophysical datasets using Gramian spaces of model parameters and Gramian constraints, computed as determinants of the corresponding Gram matrices of the multimodal model parameters and/or their attributes. The basic underlying idea of this approach is that the Gramian provides a measure of correlation between the model parameters. By imposing an additional requirement of the minimum of the Gramian, we arrive at the solution of the joint multimodal inverse problem with the enhanced correlation between the different model parameters and/or their attributes. We demonstrate that this new approach is a generalized technique that can be applied to the simultaneous joint inversion of any number and combination of geophysical datasets. Our approach includes as special cases those extant methods based on correlations and/or structural constraints of different physical properties. We illustrate this approach by a model study of reservoir monitoring using different geophysical data.

  9. The NASA Astrophysics Data System: Free Access to the Astronomical Literature On-line and through Email

    NASA Astrophysics Data System (ADS)

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

    2002-10-01

    The Astrophysics Data System (ADS) provides access to the astronomical literature through the World Wide Web. It is a NASA funded project and access to all the ADS services is free to everybody world-wide. The ADS Abstract Service allows the searching of four databases with abstracts in Astronomy, Instrumentation, Physics/Geophysics, and the LANL Preprints with a total of over 2.2 million references. The system also provides access to reference and citation information, links to on-line data, electronic journal articles, and other on-line information. The ADS Article Service contains the full articles for most of the astronomical literature back to volume 1. It contains the scanned pages of all the major journals (Astrophysical Journal, Astronomical Journal, Astronomy & Astrophysics, Monthly Notices of the Royal Astronomical Society, and Solar Physics), as well as most smaller journals back to volume 1. The ADS can be accessed through any web browser without signup or login. Alternatively an email interface is available that allows our users to execute queries via email and to retrieve scanned articles via email. This might be interesting for users on slow or unreliable links, since the email system will retry sending information automatically until the transfer is complete. There are now 9 mirror sites of the ADS available in different parts of the world to improve access. The ADS is available at: http://ads.harvard.edu

  10. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    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.

  11. 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

  12. 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/.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 22nd Texas Symposium on Relativistic Astrophysics

    SciTech Connect

    Elliott Bloom

    2005-04-01

    The XXII Texas Symposium on Relativistic Astrophysics, jointly organized by the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), the Stanford Linear Accelerator Center, and the Physics Department of Stanford University, was held on December 13-17, 2004. Following the tradition of past Texas Symposia the presentations emphasized recent developments in Cosmology, High Energy Astrophysics and the frontiers between these and Gravitation and Particle Physics. This Symposium was attended by more than 500 colleagues from a spectrum of disciplines mentioned above. There were 9 Plenary Sessions, 3 Parallel Sessions and 2 Poster Sessions held during the five-day program, with 76 oral and 240 poster presentations. These are now documented on CD and in the eConf proceedings archive. Funding of $15,000 received from the DOE under award DE-FG02-05ER41362 was used for expenses related to facility, local transportation and administrative expenses.

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

    PubMed

    Bennett, Charles L

    2005-02-11

    Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics. PMID:15705841

  1. 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.

  2. 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.

  3. 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.

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

    SciTech Connect

    Smith, Michael Scott

    2011-01-01

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

  5. The golden age of multifrequency astrophysics

    NASA Astrophysics Data System (ADS)

    Giovannelli, Franco; Sabau-Graziati, Lola

    In occasion of the Silver Jubilee of the Frascati Workshop about Multifrequency Behaviour of High Energy Cosmic Sources we want to discuss some aspects of the Multifrequency Astrophysics. Multifrequency Astrophysics can be considered as a `new field' of astrophysics born just around the end of 1970-ies - beginning of 1980-ies to which we strongly contributed not only with our own measurements and studies of physical processes spread along the whole electromagnetic spectrum, but mostly with the organization of the Frascati Workshop Series. In this paper we discuss the methodology used in astrophysics for collecting data coming from multifrequency observations of cosmic sources - obtained in different ways - and the relative models developed through theoretical study of physical processes governing their behaviour. Several examples about X-ray binaries, cataclysmic variables, T Tauri stars, relativistic jets from different classes of sources, gamma-ray bursts, and few words about Standard Big Bang Cosmology and experimental proofs fitting the theory will be discussed. We will briefly discuss also the prospects of the multifrequency astrophysics which is now in its golden age without any pretension of completness.

  6. Archaeological geophysics in Israel: past, present and future

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.

    2010-04-01

    In Israel occur a giant number of archaeological objects of various age, origin and size. Different kinds of noise complicate geophysical methods employment at archaeological sites. Geodynamical active, multi-layered, and geologically variable surrounding media in many cases damages ancient objects and disturbs their physical properties. This calls to application of different geophysical methods armed by the modern interpretation technology. The main attention is focused on the geophysical methods most frequently applying in Israeli archaeological sites: GPR and high-precise magnetic survey. Other methods (paleomagnetic, resistivity, near-surface seismics, piezoelectric, etc.) are briefly described and reviewed. The number of employed geophysical methodologies is constantly increasing, and now Israeli territory may be considered as a peculiar polygon for various geophysical methods testing. Several examples illustrate effective application of geophysical methods over some typical archaeological remains. The geophysical investigations at archaeological sites in Israel could be tentatively divided on three stages: (1) past (1990), (2) present (1990-2009), and (3) future (2010). The past stage with several archaeoseismic reviews and very limited application of geophysical methods was replaced by the present stage with the violent employment of numerous geophysical techniques. It is supposed that the future stage will be characterized by extensive development of multidiscipline physical-archaeological databases, employment of all possible indicators for 4-D monitoring and ancient sites reconstruction, as well as application of combined geophysical multilevel surveys using remote operated vehicles at low altitudes.

  7. Nonlinear, relativistic Langmuir waves in astrophysical magnetospheres

    NASA Technical Reports Server (NTRS)

    Chian, Abraham C.-L.

    1987-01-01

    Large amplitude, electrostatic plasma waves are relevant to physical processes occurring in the astrophysical magnetospheres wherein charged particles are accelerated to relativistic energies by strong waves emitted by pulsars, quasars, or radio galaxies. The nonlinear, relativistic theory of traveling Langmuir waves in a cold plasma is reviewed. The cases of streaming electron plasma, electronic plasma, and two-streams are discussed.

  8. 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

  9. 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...

  10. 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...