Statistical learning in high energy and astrophysics

International Nuclear Information System (INIS)

Zimmermann, J.

2005-01-01

This thesis studies the performance of statistical learning methods in high energy and astrophysics where they have become a standard tool in physics analysis. They are used to perform complex classification or regression by intelligent pattern recognition. This kind of artificial intelligence is achieved by the principle ''learning from examples'': The examples describe the relationship between detector events and their classification. The application of statistical learning methods is either motivated by the lack of knowledge about this relationship or by tight time restrictions. In the first case learning from examples is the only possibility since no theory is available which would allow to build an algorithm in the classical way. In the second case a classical algorithm exists but is too slow to cope with the time restrictions. It is therefore replaced by a pattern recognition machine which implements a fast statistical learning method. But even in applications where some kind of classical algorithm had done a good job, statistical learning methods convinced by their remarkable performance. This thesis gives an introduction to statistical learning methods and how they are applied correctly in physics analysis. Their flexibility and high performance will be discussed by showing intriguing results from high energy and astrophysics. These include the development of highly efficient triggers, powerful purification of event samples and exact reconstruction of hidden event parameters. The presented studies also show typical problems in the application of statistical learning methods. They should be only second choice in all cases where an algorithm based on prior knowledge exists. Some examples in physics analyses are found where these methods are not used in the right way leading either to wrong predictions or bad performance. Physicists also often hesitate to profit from these methods because they fear that statistical learning methods cannot be controlled in a

Statistical learning in high energy and astrophysics

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, J.

2005-06-16

This thesis studies the performance of statistical learning methods in high energy and astrophysics where they have become a standard tool in physics analysis. They are used to perform complex classification or regression by intelligent pattern recognition. This kind of artificial intelligence is achieved by the principle ''learning from examples'': The examples describe the relationship between detector events and their classification. The application of statistical learning methods is either motivated by the lack of knowledge about this relationship or by tight time restrictions. In the first case learning from examples is the only possibility since no theory is available which would allow to build an algorithm in the classical way. In the second case a classical algorithm exists but is too slow to cope with the time restrictions. It is therefore replaced by a pattern recognition machine which implements a fast statistical learning method. But even in applications where some kind of classical algorithm had done a good job, statistical learning methods convinced by their remarkable performance. This thesis gives an introduction to statistical learning methods and how they are applied correctly in physics analysis. Their flexibility and high performance will be discussed by showing intriguing results from high energy and astrophysics. These include the development of highly efficient triggers, powerful purification of event samples and exact reconstruction of hidden event parameters. The presented studies also show typical problems in the application of statistical learning methods. They should be only second choice in all cases where an algorithm based on prior knowledge exists. Some examples in physics analyses are found where these methods are not used in the right way leading either to wrong predictions or bad performance. Physicists also often hesitate to profit from these methods because they fear that statistical learning methods cannot

Laboratory Astrophysics Using High Energy Density Photon and Electron Beams

CERN Document Server

Bingham, Robert

2005-01-01

The development of intense laser and particle beams has opened up new opportunities to study high energy density astrophysical processes in the Laboratory. With even higher laser intensities possible in the near future vacuum polarization processes such as photon - photon scattering with or without large magnetic fields may also be experimentally observed. In this talk I will review the status of laboratory experiments using intense beans to investigate extreme astrophysical phenomena such as supernovae explosions, gamma x-ray bursts, ultra-high energy cosmic accelerators etc. Just as intense photon or electron beams can excite relativistic electron plasma waves or wakefields used in plasma acceleration, intense neutrino beams from type II supernovae can also excite wakefields or plasma waves. Other instabilities driven by intense beams relevant to perhaps x-ray bursts is the Weibel instability. Simulation results of extreme processes will also be presented.

IceCube: Particle Astrophysics with High Energy Neutrinos

CERN Multimedia

Université de Genève

2012-01-01

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

HEASARC - The High Energy Astrophysics Science Archive Research Center

Science.gov (United States)

Smale, Alan P.

2011-01-01

The High Energy Astrophysics Science Archive Research Center (HEASARC) is NASA's archive for high-energy astrophysics and cosmic microwave background (CMB) data, supporting the broad science goals of NASA's Physics of the Cosmos theme. It provides vital scientific infrastructure to the community by standardizing science data formats and analysis programs, providing open access to NASA resources, and implementing powerful archive interfaces. Over the next five years the HEASARC will ingest observations from up to 12 operating missions, while serving data from these and over 30 archival missions to the community. The HEASARC archive presently contains over 37 TB of data, and will contain over 60 TB by the end of 2014. The HEASARC continues to secure major cost savings for NASA missions, providing a reusable mission-independent framework for reducing, analyzing, and archiving data. This approach was recognized in the NRC Portals to the Universe report (2007) as one of the HEASARC's great strengths. This poster describes the past and current activities of the HEASARC and our anticipated developments in coming years. These include preparations to support upcoming high energy missions (NuSTAR, Astro-H, GEMS) and ground-based and sub-orbital CMB experiments, as well as continued support of missions currently operating (Chandra, Fermi, RXTE, Suzaku, Swift, XMM-Newton and INTEGRAL). In 2012 the HEASARC (which now includes LAMBDA) will support the final nine-year WMAP data release. The HEASARC is also upgrading its archive querying and retrieval software with the new Xamin system in early release - and building on opportunities afforded by the growth of the Virtual Observatory and recent developments in virtual environments and cloud computing.

The Advanced Telescope for High Energy Astrophysics

Science.gov (United States)

Guainazzi, Matteo

2017-08-01

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

Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

International Nuclear Information System (INIS)

R Paul Drake

2004-01-01

OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

Nuclear interactions in high energy heavy ions and applications in astrophysics

International Nuclear Information System (INIS)

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

1993-01-01

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. 4 He, 16 O, 20 Ne, 28 Si, 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 16 O, 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

5th International conference on High Energy Density Laboratory Astrophysics

CERN Document Server

Kyrala, G.A

2005-01-01

During the past several years, research teams around the world have developed astrophysics-relevant utilizing high energy-density facilities such as intense lasers and z-pinches. Research is underway in many areas, such as compressible hydrodynamic mixing, strong shock phenomena, radiation flow, radiative shocks and jets, complex opacities, equations o fstat, and relativistic plasmas. Beyond this current research and the papers it is producing, plans are being made for the application, to astrophysics-relevant research, of the 2 MJ National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory; the 600 kj Ligne d'Intergration Laser (LIL) and the 2 MJ Laser Megajoule (LMJ) in Bordeaux, France; petawatt-range lasers now under construction around the world; and current and future Z pinches. The goal of this conference and these proceedings is to continue focusing and attention on this emerging research area. The conference brought together different scientists interested in this emerging new fi...

Oscillation effects on high-energy neutrino fluxes from astrophysical hidden sources

International Nuclear Information System (INIS)

Mena, Olga; Mocioiu, Irina; Razzaque, Soebur

2007-01-01

High-energy neutrinos are expected to be produced in a variety of astrophysical sources as well as in optically thick hidden sources. We explore the matter-induced oscillation effects on emitted neutrino fluxes of three different flavors from the latter class. We use the ratio of electron and tau induced showers to muon tracks, in upcoming neutrino telescopes, as the principal observable in our analysis. This ratio depends on the neutrino energy, density profile of the sources, and on the oscillation parameters. The largely unknown flux normalization drops out of our calculation and only affects the statistics. For the current knowledge of the oscillation parameters we find that the matter-induced effects are non-negligible and the enhancement of the ratio from its vacuum value takes place in an energy range where the neutrino telescopes are the most sensitive. Quantifying the effect would be useful to learn about the astrophysics of the sources as well as the oscillation parameters. If the neutrino telescopes mostly detect diffuse neutrinos without identifying their sources, then any deviation of the measured flux ratios from the vacuum expectation values would be most naturally explained by a large population of hidden sources for which matter-induced neutrino oscillation effects are important

Laboratory astrophysics with high energy and high power lasers: from radiative shocks to young star jets

International Nuclear Information System (INIS)

Diziere, A.

2012-01-01

Laboratory astrophysics are a rapidly developing domain of the High Energy Density Physics. It aims to recreate at smaller scales physical processes that astronomical telescopes have difficulties observing. We shall approach, in this thesis, three major subjects: 1) Jets ejected from young stars, characterized by an important collimation degree and ending with a bow shock; 2) Radiative shocks in which radiation emitted by the shock front itself plays a dominant role in its structure and 3) Accretion shocks in magnetic cataclysmic variables whose important cooling factor allows them to reach stationarity. From the conception to experimental realization, we shall attempt to reproduce in laboratory each of these processes by respecting the scaling laws linking both situations (experimental and astrophysical) established beforehand. The implementation of a large array of visible and X-ray diagnostics will finally allow to completely characterize them and calculate the dimensionless numbers that validate the astrophysical relevance. (author) [fr

High energy astrophysics with ground-based gamma ray detectors

International Nuclear Information System (INIS)

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

2008-01-01

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

Solar High-energy Astrophysical Plasmas Explorer (SHAPE). Volume 1: Proposed concept, statement of work and cost plan

Science.gov (United States)

Dennis, Brian R.; Martin, Franklin D.; Prince, T.; Lin, R.; Bruner, M.; Culhane, L.; Ramaty, R.; Doschek, G.; Emslie, G.; Lingenfelter, R.

1986-01-01

The concept of the Solar High-Energy Astrophysical Plasmas Explorer (SHAPE) is studied. The primary goal is to understand the impulsive release of energy, efficient acceleration of particles to high energies, and rapid transport of energy. Solar flare studies are the centerpieces of the investigation because in flares these high energy processes can be studied in unmatched detail at most wavelenth regions of the electromagnetic spectrum as well as in energetic charged particles and neutrons.

On the origin of very-high-energy photons in astrophysics: a short introduction to acceleration and radiation physics

International Nuclear Information System (INIS)

Lemoine, M.; Pelletier, G.

2015-01-01

Powerful astrophysical sources produce non-thermal spectra of very-high-energy photons, with generic power-law distributions, through various radiative processes of charged particles, e.g., synchrotron radiation, inverse Compton processes, and hadronic interactions. Those charged particles have themselves been accelerated to ultra-relativistic energies in intense electromagnetic fields in the source. In many cases, the exact acceleration scheme is not known, but standard scenarios, such as Fermi mechanisms and reconnection processes are generally considered as prime suspects for the conversion of bulk kinetic or electromagnetic energy into a power law of supra-thermal particles. This paper proposes a short introduction to the various acceleration and radiative processes which shape the distributions of very-high-energy photons (E > 100 MeV) in astrophysics. (authors)

Nonlocal astrophysics dark matter, dark energy and physical vacuum

CERN Document Server

Alexeev, Boris V

2017-01-01

Non-Local Astrophysics: Dark Matter, Dark Energy and Physical Vacuum highlights the most significant features of non-local theory, a highly effective tool for solving many physical problems in areas where classical local theory runs into difficulties. The book provides the fundamental science behind new non-local astrophysics, discussing non-local kinetic and generalized hydrodynamic equations, non-local parameters in several physical systems, dark matter, dark energy, black holes and gravitational waves. Devoted to the solution of astrophysical problems from the position of non-local physics Provides a solution for dark matter and dark energy Discusses cosmological aspects of the theory of non-local physics Includes a solution for the problem of the Hubble Universe expansion, and of the dependence of the orbital velocity from the center of gravity

High-energy Nd:glass laser facility for collisionless laboratory astrophysics

International Nuclear Information System (INIS)

Niemann, C; Constantin, C G; Schaeffer, D B; Lucky, Z; Gekelman, W; Everson, E T; Tauschwitz, A; Weiland, T; Winske, D

2012-01-01

A kilojoule-class laser (Raptor) has recently been activated at the Phoenix-laser-facility at the University of California Los Angeles (UCLA) for an experimental program on laboratory astrophysics in conjunction with the Large Plasma Device (LAPD). The unique combination of a high-energy laser system and the 18 meter long, highly-magnetized but current-free plasma will support a new class of plasma physics experiments, including the first laboratory simulations of quasi-parallel collisionless shocks, experiments on magnetic reconnection, or advanced laser-based diagnostics of basic plasmas. Here we present the parameter space accessible with this new instrument, results from a laser-driven magnetic piston experiment at reduced power, and a detailed description of the laser system and its performance.

Astrophysical relevance of γ transition energies

International Nuclear Information System (INIS)

Rauscher, Thomas

2008-01-01

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

Experimental astrophysics with high power lasers and Z pinches

Energy Technology Data Exchange (ETDEWEB)

Remington, B A; Drake, R P; Ryutov, D D

2004-12-10

With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

The goals of gamma-ray spectroscopy in high energy astrophysics

Science.gov (United States)

Lingenfelter, Richard E.; Higdon, James C.; Leventhal, Marvin; Ramaty, Reuven; Woosley, Stanford E.

1990-01-01

The use of high resolution gamma-ray spectroscopy in astrophysics is discussed with specific attention given to the application of the Nuclear Astrophysics Explorer (NAE). The gamma-ray lines from nuclear transitions in radionucleic decay and positron annihilation permits the study of current sites, rates and models of nucleosynthesis, and galactic structure. Diffuse galactic emission is discussed, and the high-resolution observations of gamma-ray lines from discrete sites are also described. Interstellar mixing and elemental abundances can also be inferred from high-resolution gamma-ray spectroscopy of nucleosynthetic products. Compact objects can also be examined by means of gamma-ray emissions, allowing better understanding of neutron stars and the accreting black hole near the galactic center. Solar physics can also be investigated by examining such features as solar-flare particle acceleration and atmospheric abundances.

Relevance of axionlike particles for very-high-energy astrophysics

International Nuclear Information System (INIS)

De Angelis, Alessandro; Galanti, Giorgio; Roncadelli, Marco

2011-01-01

Several extensions of the standard model and, in particular, superstring theories suggest the existence of axionlike particles (ALPs), which are very light spin-zero bosons with a two-photon coupling. As a consequence, photon-ALP oscillations occur in the presence of an external magnetic field, and ALPs can lead to observable effects on the measured photon spectrum of astrophysical sources. An intriguing situation arises when blazars are observed in the very-high-energy (VHE) band--namely, above 100 GeV--as it is the case with the presently operating Imaging Atmospheric Cherenkov Telescopes H.E.S.S, Major Atmospheric Gamma Imaging Cherenkov telescope, Collaboration of Australia and Nippon for a Gamma Ray Observatory in the Outback III, and VERITAS. The extragalactic background light produced by galaxies during cosmic evolution gives rise to a source dimming which becomes important in the VHE band and increases with energy, since hard photons from a blazar scatter off soft extragalactic background light photons thereby disappearing into e + e - pairs. This dimming can be considerably reduced by photon-ALP oscillations, and since they are energy independent the resulting blazar spectra become harder than expected. We consider throughout a scenario first proposed by De Angelis, Roncadelli, and Mansutti in which the above strategy is implemented with photon-ALP oscillations triggered by large-scale magnetic fields, and we systematically investigate its implications for VHE blazars. We find that for ALPs lighter than 5·10 -10 eV the photon survival probability is larger than predicted by conventional physics above a few hundred GeV. Specifically, a boost factor of 10 can easily occur for sources at large distance and large energy, e.g. at 8 TeV for the blazar 1ES 0347-121 at redshift z=0.188. This is a clear-cut prediction which can be tested with the planned Cherenkov Telescope Array and the High Altitude Water Cherenkov Experiment (HAWC) water Cherenkov �

Scientific and technical progress in high-energy astrophysics at INPE

International Nuclear Information System (INIS)

Bui-Van, N.A.; Jayanthi, U.B.; Jardim, J.O.D.; Braga, J.; Santo, C.M.E.

1984-01-01

The recent advances in high-energy Astrophysics pertains to the study of compact objects in galactic nuclei, binary systems and pulsars. These aspects are best understood by the study of the emissions in X- and gamma rays of these objects through the temporal variation in flux and spectrum. The Southern Hemisphere offers some of the unique objects for investigations such as galactic center, the Vela pulsar etc. For high temporal and spectra resolution studies two telescopes 'GeLi' and 'Pulsar' were designed and constructed. To support these scientific activities, a program in balloon launching and data acquisition facilities has been developed since 1971. The 'Balloon Launching Center' of INPE has capacity to launch balloons of -850,000 m 3 with payloads weighting about 1,000 Kg. Taking advantage of these facilities, project 'Bantar', with the goal to measure the atmospheric gamma-ray radiation in the Antartic Region, is under progress. (Author) [pt

Fullerenes, PAHs, Amino Acids and High Energy Astrophysics

Directory of Open Access Journals (Sweden)

Susana Iglesias-Groth

2014-12-01

Full Text Available We present theoretical, observational and laboratory work on the spectral properties of fullerenes and hydrogenated fullerenes. Fullerenes in its various forms (individual, endohedral, hydrogenated, etc. can contribute to the UV bump in the extinction curves measured in many lines of sight of the Galaxy. They can also produce a large number of absorption features in the optical and near infrared which could be associated with diffuse interstellar bands. We summarise recent laboratory work on the spectral characterisation of fullerenes and hydrogenated fullerenes (for a range of temperatures. The recent detection of mid-IR bands of fullerenes in various astrophysical environments (planetary nebulae, reflection nebulae provide additional evidence for a link between fullerene families and diffuse interstellar bands. We describe recent observational work on near IR bands of C60+ in a protoplanetary nebula which support fullerene formation during the post-AGB phase. We also report on the survival of fullerenes to irradiation by high energy particles and gamma photons and laboratory work to explore the chemical  reactions that take place when fullerenes are exposed to this radiations in the presence of water, ammonia and other molecules as a potential path to form amino acids.

Particle and astrophysics aspects of ultrahigh energy cosmic rays

International Nuclear Information System (INIS)

Sigl, G.

2001-01-01

The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with γ-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

Particle and astrophysics aspects of ultrahigh energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Sigl, G [Institut d' Astrophysique de Paris, Paris (France)

2001-11-15

The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with {gamma}-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

Matter effects on the flavor conversions of solar neutrinos and high-energy astrophysical neutrinos

Science.gov (United States)

Huang, Guo-yuan; Liu, Jun-Hao; Zhou, Shun

2018-06-01

Can we observe the solar eclipses in the neutrino light? In principle, this is possible by identifying the lunar matter effects on the flavor conversions of solar neutrinos when they traverse the Moon before reaching the detectors at the Earth. Unfortunately, we show that the lunar matter effects on the survival probability of solar 8B neutrinos are suppressed by an additional factor of 1.2%, compared to the day-night asymmetry. However, we point out that the matter effects on the flavor conversions of high-energy astrophysical neutrinos, when they propagate through the Sun, can be significant. Though the flavor composition of high-energy neutrinos can be remarkably modified, it is quite challenging to observe such effects even in the next-generation of neutrino telescopes.

Extreme Energy Particle Astrophysics with ANITA-V

Science.gov (United States)

Wissel, Stephanie

This proposal is in collaboration with Peter Gorham at the University of Hawaii, who is the PI of the lead proposal. Co-I Wissel and her group at California Polytechnic State University (Cal Poly) will be responsible for calibration equipment upgrades, calibration equipment, and deployment of the calibration system. The Cal Poly group is planning to provide calibration hardware and software products in support of the analysis of ANITAV data in search of ultra high-energy (UHE) neutrinos and cosmic rays. Wissel (now at Cal Poly, a new collaborating institution for ANITA-5) brings significant experience in the detection of high-energy and ultra-high energy particles to the collaboration, leveraging her thirteen years of experience in particle astrophysics and previous work on ANITA-III and ANITA-IV.

Evaluation of the astrophysical origin of a vertical high-energy neutrino event in IceCube using IceTop information

Energy Technology Data Exchange (ETDEWEB)

Stahlberg, Martin; Auffenberg, Jan; Rongen, Martin; Kemp, Julian; Hansmann, Bengt; Schaufel, Merlin; Wiebusch, Christopher [RWTH Aachen, III. Physikalisches Institut B, Otto-Blumenthal-Strasse, 52074 Aachen (Germany); Collaboration: IceCube-Collaboration

2015-07-01

A main goal of the IceCube neutrino observatory is the detection of high-energy astrophysical neutrinos. IceCube's surface detector component IceTop is an array of 81 stations comprised of two Cherenkov-light detecting tanks, each of which is filled with clear ice and contains two photomultiplier modules. IceTop allows for the detection of cosmic-ray induced air-showers above energies of a few 100 TeV. In addition, the atmospheric origin of neutrino events detected with IceCube can be verified by the observation of a coincident air-shower component on the surface with IceTop. In 2014, a vertically down-going high-energy muon neutrino event starting in IceCube has been observed. The astrophysical origin of this event is tested by a close examination of the IceTop data. The outcome of this analysis is used to assess the potential of the proposed IceTop extension, IceVeto, which further increases the geometrical acceptance of the surface detector.

Status of the GILDA project for the 30 MeV-100 GeV high energy gamma ray astrophysics

Energy Technology Data Exchange (ETDEWEB)

Casolino, M.; Sparvoli, R.; Morselli, A.; Picozza, P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Barbiellini, G. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Fuglesang, C. [ESA-EAC, Cologne (Germany); Ozerov, Yu.V.; Zemskov, V.M.; Zverev, V.G.; Galper, A.M. [Moscow Engineering Physics Institute, Moscow (Russian Federation)

1995-09-01

High energy gamma-ray astrophysics has greatly developed in the last few years because of the results of EGRET, on the Compton gamma ray observatory. The satellite observations have shown the importance of continuing the investigation of high energy gamma radiation but the emerging of new astrophysical and cosmological problems require for future experiments the realization of telescopes with parameters significatively improved with respect to the previous missions. In a traditional point of view, this is achieved with the increase of the length L of the device and, consequently, the mass of the telescope and satellite (growing as L{sup 3}). Such kinds of experiments are becoming rather expensive and are approaching the maximum value in cost, satellite mass and consuming resources. The telescope project GILDA presented in this paper is based on the use of silicon strip detectors. The silicon technique consents to obtain a much wider solid angle aperture; in this way there is more sensitivity without a growing in the size of the

Status of the GILDA project for the 30 MeV-100 GeV high energy gamma ray astrophysics

International Nuclear Information System (INIS)

Casolino, M.; Sparvoli, R.; Morselli, A.; Picozza, P.; Barbiellini, G.; Fuglesang, C.; Ozerov, Yu.V.; Zemskov, V.M.; Zverev, V.G.; Galper, A.M.

1995-01-01

High energy gamma-ray astrophysics has greatly developed in the last few years because of the results of EGRET, on the Compton gamma ray observatory. The satellite observations have shown the importance of continuing the investigation of high energy gamma radiation but the emerging of new astrophysical and cosmological problems require for future experiments the realization of telescopes with parameters significatively improved with respect to the previous missions. In a traditional point of view, this is achieved with the increase of the length L of the device and, consequently, the mass of the telescope and satellite (growing as L 3 ). Such kinds of experiments are becoming rather expensive and are approaching the maximum value in cost, satellite mass and consuming resources. The telescope project GILDA presented in this paper is based on the use of silicon strip detectors. The silicon technique consents to obtain a much wider solid angle aperture; in this way there is more sensitivity without a growing in the size of the

The Cherenkov Telescope Array For Very High-Energy Astrophysics

Science.gov (United States)

Kaaret, Philip

2015-08-01

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

High Energy Astrophysics Tests of Lorentz Invariance and Quantum Gravity Models

Science.gov (United States)

Stecker, Floyd W.

2012-01-01

High energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approx.10(exp -35) m. I will discuss the possible signatures of Lorentz invariance violation (LIV) that can be manifested by observing of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) on the fraction of LIV at a Lorentz factor of approx. 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space-based detection techniques to improve searches for LIV in the future. I will also discuss how the LIV formalism casts doubt on the OPERA superluminal neutrino claim.

Cosmic physics: the high energy frontier

International Nuclear Information System (INIS)

Stecker, F W

2003-01-01

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

The astrophysical S factor for dd reaction at ultralow energies

International Nuclear Information System (INIS)

Bystritskii, Vit.M.; Bystritsky, V.M.; Grebenyuk, V.M.

2001-01-01

The experimental results of measurements of the astrophysical S factor for dd reaction at very low deuteron collision energies using liner plasma technique are presented. The experiment was fulfilled at the high-current generator of the High-Current Electronics Institute (Tomsk, Russia). The measured values of S factors for the deuteron collision energies 1.80, 2.06, and 2.27 keV are S dd = 114 ± 68, 64 ± 30, and 53 ± 16 keV b, respectively. The corresponding cross sections for dd reaction, described as a product of the barrier factor and measured astrophysical S factor are: σ dd n (E col = 1.80 keV) = (4.3 ± 2.6) x 10 -33 cm 2 ; σ dd n (E col = 2.06 keV) = (9.8 ± 4.6) x 10 -33 cm 2 ; σ dd n (E col = 2.27 keV) = (2.1 ± 0.6) x 10 -32 cm 2 [ru

Experimental studies of keV energy neutron-induced reactions relevant to astrophysics and nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Shima, T.; Kii, T.; Kikuchi, T.; Okazaki, F.; Kobayashi, T.; Baba, T.; Nagai, Y. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Igashira, M.

1997-03-01

Nuclear reactions induced by keV energy neutrons provide a plenty of informations for studies of both astrophysics and nuclear physics. In this paper we will show our experimental studies of neutron- induced reactions of light nuclei in the keV energy region by means of a pulsed keV neutron beam and high-sensitivity detectors. Also we will discuss astrophysical and nuclear-physical consequences by using the obtained results. (author)

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

Science.gov (United States)

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.

ENERGY RELAXATION OF HELIUM ATOMS IN ASTROPHYSICAL GASES

International Nuclear Information System (INIS)

Lewkow, N. R.; Kharchenko, V.; Zhang, P.

2012-01-01

We report accurate parameters describing energy relaxation of He atoms in atomic gases, important for astrophysics and atmospheric science. Collisional energy exchange between helium atoms and atomic constituents of the interstellar gas, heliosphere, and upper planetary atmosphere has been investigated. Energy transfer rates, number of collisions required for thermalization, energy distributions of recoil atoms, and other major parameters of energy relaxation for fast He atoms in thermal H, He, and O gases have been computed in a broad interval of energies from 10 meV to 10 keV. This energy interval is important for astrophysical applications involving the energy deposition of energetic atoms and ions into atmospheres of planets and exoplanets, atmospheric evolution, and analysis of non-equilibrium processes in the interstellar gas and heliosphere. Angular- and energy-dependent cross sections, required for an accurate description of the momentum-energy transfer, are obtained using ab initio interaction potentials and quantum mechanical calculations for scattering processes. Calculation methods used include partial wave analysis for collisional energies below 2 keV and the eikonal approximation at energies higher than 100 eV, keeping a significant energy region of overlap, 0.1-2 keV, between these two methods for their mutual verification. The partial wave method and the eikonal approximation excellently match results obtained with each other as well as experimental data, providing reliable cross sections in the astrophysically important interval of energies from 10 meV to 10 keV. Analytical formulae, interpolating obtained energy- and angular-dependent cross sections, are presented to simplify potential applications of the reported database. Thermalization of fast He atoms in the interstellar gas and energy relaxation of hot He and O atoms in the upper atmosphere of Mars are considered as illustrative examples of potential applications of the new database.

Nuclear interactions of high energy heavy ions and applications in astrophysics

International Nuclear Information System (INIS)

Wefel, J.P.

1992-01-01

This program was established for the purpose of studying projectile fragmentation; (1) as a function of energy, focusing first on the intermediate energy region, < 1 GeV/nucleon, where there have been few previous measurements and no systematic studies, and (2) as a function of projectile mass, starting with light beams and proceeding to species as heavy as nickel (and possibly beyond). The intermediate energy region is important as the transition between the lower energy data, where the interaction appears to be dominated by collective effects and the decay of excited nuclei, and the highest energy results, where nucleon-nucleon interactions are fundamental, ''limiting fragmentation'' applies, and the nucleus may well break-up before any de-excitation. The mass dependence of projectile fragmentation is largely unknown since most detailed work has involved light ion beams. Nuclear structure effects, for example, may well be quite prominent for heavier beams. Furthermore, the nuclear excitation functions for the production of different fragment isotopes have immediate application to the astrophysical interpretation of existing isotopic datasets obtained from balloon and satellite measurements of galactic cosmic rays

Extensive Air Showers High Energy Phenomena and Astrophysical Aspects - A Tutorial, Reference Manual and Data Book

CERN Document Server

Grieder, Peter K.F

2010-01-01

Extensive air showers are a very unique phenomenon. In the more than six decades since their discovery by Auger et al. we have learned a great deal about these extremely energetic events and gained deep insights into high-energy phenomena, particle physics and astrophysics. In this Tutorial, Reference Manual and Data Book Peter K. F. Grieder provides the reader with a comprehensive view of the phenomenology and facts of the various types of interactions and cascades, theoretical background, experimental methods, data evaluation and interpretation, and air shower simulation. He discusses astrophysical aspects of the primary radiation and addresses the questions that continue to puzzle researchers. The book is divided into two parts, each in its own separate volume: Part I in Volume I deals mainly with the basic theoretical framework of the processes that determine an air shower and ends with a summary of ways to extract information on the primary radiation from air shower observations. It also presents a compi...

The astrophysical S-factor for dd-reactions at keV-energy range

International Nuclear Information System (INIS)

Bystritskii, V.; Bystritsky, V.; Chaikovsky, S.

2001-01-01

The experimental results of measurements of the astrophysical S-factor for dd-reaction at keV-energy range collision energies using liner plasma technique are presented. The experiments were carried out at the high current generator of the Institute of High-Current Electronics in Tomsk, Russia. The measured values of the S-factors for the deuteron collision energies 1.80, 2.06 and 2.27 keV are S dd =(114±68), (64±30), (53±16) b x keV, respectively. The corresponding cross sections for dd-reactions, described as a product of the barrier factor and measured astrophysical S-factor, are σ dd n (E col =1.80 keV)=(4.3±2.6) x 10 -33 cm 2 ; σ dd n (E col =2.06 keV)=(9.8±4.6) x 10 -33 cm 2 ; σ dd n (E col =2.27 keV)=(2.1±0.6) x 10 -32 cm 2 . (orig.) [de

High energy neutrinos: sources and fluxes

Energy Technology Data Exchange (ETDEWEB)

Stanev, Todor [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark DE 19716 (United States)

2006-05-15

We discuss briefly the potential sources of high energy astrophysical neutrinos and show estimates of the neutrino fluxes that they can produce. A special attention is paid to the connection between the highest energy cosmic rays and astrophysical neutrinos.

The astrophysical S-factor for the dd-reaction at ultralow energies

International Nuclear Information System (INIS)

Bystritskij, V.M.; Grebenyuk, V.M.; Parzhitskij, S.S.

1999-01-01

The experimental results for measurements of the astrophysical S-factor for dd-reaction at very low deuteron collision energies using liner plasma technique are presented. The experiment was fulfilled at the high current generator of the High-Current Electronics Institute, Tomsk, Russia. The measured values of S-factor for the deuteron collision energies: 2.27, 2.06, and 1.8 keV are: S dd = (53 ± 16), (64 ± 30), (114 ±68)b · keV, respectively. The corresponding dd cross sections described as a product of the barrier factor and measured astrophysical S-factor are: σ dd n (E col = 1.8 keV) = (4.3 ± 2.6) · 10 -33 cm 2 ; σ dd n (E col = 2.06 keV) = (9.8 ± 4.6) · 10 -33 cm 2 ; σ dd n (E col = 2.27 keV) = (2.1 ±0.6) · 10 -32 cm 2

S-factor for radiative capture reactions for light nuclei at astrophysical energies

Science.gov (United States)

Ghasemi, Reza; Sadeghi, Hossein

2018-06-01

The astrophysical S-factors of thermonuclear reactions, including radiative capture reactions and their analysis in the frame of different theoretical models, are the main source of nuclear processes. We have done research on the radiative capture reactions importance in the framework of a potential model. Investigation of the reactions in the astrophysical energies is of great interest in the aspect of astrophysics and nuclear physics for developing correct models of burning and evolution of stars. The experimental measurements are very difficult and impossible because of these reactions occurrence at low-energies. In this paper we do a calculation on radiative capture astrophysical S-factors for nuclei in the mass region A theoretical methods.

Proceedings of the topical conference on nuclear physics, high energy physics and astrophysics (NPHEAP-2010)

International Nuclear Information System (INIS)

Vo Van Thuan; Tran Duc Thiep; Le Hong Khiem

2011-01-01

There were roughly 80 scientists gathering for the NPHEAP-2010 and there 61 oral talks and posters have been presented. The audience has been introduced to the status of long term nuclear power program of Vietnam up to 2030. One of the highlights for near future activity of Vietnamese nuclear sector should be the manpower training and education for this huge master plan. Most of invited and contributed papers have devoted to both basic nuclear physics at world radioactive beams and applied nuclear instrumentation. In addition to some traditional astronomical papers, there were more contributions on advanced cosmic ray physics and related nuclear astrophysics. A few of papers on high energy and particle physics jointly showed a high interest in flavor physics at LHC, KEK and J-PARC. (NHA)

High Time Resolution Astrophysics

CERN Document Server

Phelan, Don; Shearer, Andrew

2008-01-01

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

A method of simulation of large air showers of cosmic radiation. Application to High Energy Physics and to Astrophysics (10"1"3 - 10"2"1 eV)

International Nuclear Information System (INIS)

Capdevielle, Jean-Noel

1972-01-01

This research thesis addresses the study of large air showers and the field of high energy physics and of astrophysics. The author discusses fluctuations undergone by large showers, and reports the development of a simulation method which is used for the determination of the morphology of these large air showers, that is their longitudinal and lateral development. Simulation results are compared with experimental results, and the influence of fluctuations is discussed. The author reports the application of the simulation method to high energy physics and to astrophysics, notably through an example of use of the simulation method in application to the Kiel Group experiment performed at the Pic du Midi. Possible developments are then discussed [fr

Ultra-High-Energy Cosmic Rays

CERN Document Server

Dova, M.T.

2015-05-22

The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 10 17 eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written version of a series of lectures devoted to UHECR at the 2013 CERN-Latin-American School of High-Energy Physics. We present anintroduction to acceleration mechanisms of charged particles to the highest energies in astrophysical objects, their propagation from the sources to Earth, and the experimental techniques for their detection. We also discuss some of the relevant observational results from Telescope Array and Pierre Auger Observatory. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

A new experimental setup established for low-energy nuclear astrophysics studies

International Nuclear Information System (INIS)

Chen, S.Z.; Xu, S.W.; He, J.J.; Hu, J.; Rolfs, C.E.; Zhang, N.T.; Ma, S.B.; Zhang, L.Y.; Hou, S.Q.; Yu, X.Q.; Ma, X.W.

2014-01-01

An experimental setup for low-energy nuclear astrophysics studies has been recently established at the Institute of Modern Physics (IMP), Lanzhou, China. The driver machine is a 320 kV high voltage platform, which can provide intense currents of proton, alpha and many heavy ion beams. The energy of a proton beam was calibrated against the nominal platform high voltage by using a well-known resonant reaction of 11 B(p,γ) 12 C and a non-resonant reaction 12 C(p,γ) 13 N. The accuracy was achieved to be better than ±0.5 keV. The detection system consists of a Clover-type high-purity germanium detector, a silicon detector and a plastic scintillator. The performance of the detectors was tested by several experiments. The astrophysical S-factors of the 7 Li(p,γ) 8 Be and 7 Li(p,α) 3 He reactions were measured with this new setup, and our data agree with the values found in the literature. In addition, the upgrade of our driver machine and experimental setup has been discussed. As a future goal, a fascinating National Deep Underground Laboratory in China, the deepest underground laboratory all over the world, is prospected

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

International Nuclear Information System (INIS)

Guessoum, N.

2014-01-01

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

Preface to special topic: High-energy density laboratory astrophysics

International Nuclear Information System (INIS)

Glenzer, Siegfried H

2017-01-01

Here, in the 1990s, when the large inertial confinement fusion facilities in the United States became accessible for discovery-class research, physicists soon realized that the combination of these energetic drivers with precision plasmas diagnostics would allow the unprecedented experimental study of astrophysical problems.

Traversable geometric dark energy wormholes constrained by astrophysical observations

Energy Technology Data Exchange (ETDEWEB)

Wang, Deng [Nankai University, Theoretical Physics Division, Chern Institute of Mathematics, Tianjin (China); Meng, Xin-he [Nankai University, Department of Physics, Tianjin (China); Institute of Theoretical Physics, CAS, State Key Lab of Theoretical Physics, Beijing (China)

2016-09-15

In this paper, we introduce the astrophysical observations into the wormhole research. We investigate the evolution behavior of the dark energy equation of state parameter ω by constraining the dark energy model, so that we can determine in which stage of the universe wormholes can exist by using the condition ω < -1. As a concrete instance, we study the Ricci dark energy (RDE) traversable wormholes constrained by astrophysical observations. Particularly, we find from Fig. 5 of this work, when the effective equation of state parameter ω{sub X} < -1 (or z < 0.109), i.e., the null energy condition (NEC) is violated clearly, the wormholes will exist (open). Subsequently, six specific solutions of statically and spherically symmetric traversable wormhole supported by the RDE fluids are obtained. Except for the case of a constant redshift function, where the solution is not only asymptotically flat but also traversable, the five remaining solutions are all non-asymptotically flat, therefore, the exotic matter from the RDE fluids is spatially distributed in the vicinity of the throat. Furthermore, we analyze the physical characteristics and properties of the RDE traversable wormholes. It is worth noting that, using the astrophysical observations, we obtain the constraints on the parameters of the RDE model, explore the types of exotic RDE fluids in different stages of the universe, limit the number of available models for wormhole research, reduce theoretically the number of the wormholes corresponding to different parameters for the RDE model, and provide a clearer picture for wormhole investigations from the new perspective of observational cosmology. (orig.)

Traversable geometric dark energy wormholes constrained by astrophysical observations

International Nuclear Information System (INIS)

Wang, Deng; Meng, Xin-he

2016-01-01

In this paper, we introduce the astrophysical observations into the wormhole research. We investigate the evolution behavior of the dark energy equation of state parameter ω by constraining the dark energy model, so that we can determine in which stage of the universe wormholes can exist by using the condition ω < -1. As a concrete instance, we study the Ricci dark energy (RDE) traversable wormholes constrained by astrophysical observations. Particularly, we find from Fig. 5 of this work, when the effective equation of state parameter ω X < -1 (or z < 0.109), i.e., the null energy condition (NEC) is violated clearly, the wormholes will exist (open). Subsequently, six specific solutions of statically and spherically symmetric traversable wormhole supported by the RDE fluids are obtained. Except for the case of a constant redshift function, where the solution is not only asymptotically flat but also traversable, the five remaining solutions are all non-asymptotically flat, therefore, the exotic matter from the RDE fluids is spatially distributed in the vicinity of the throat. Furthermore, we analyze the physical characteristics and properties of the RDE traversable wormholes. It is worth noting that, using the astrophysical observations, we obtain the constraints on the parameters of the RDE model, explore the types of exotic RDE fluids in different stages of the universe, limit the number of available models for wormhole research, reduce theoretically the number of the wormholes corresponding to different parameters for the RDE model, and provide a clearer picture for wormhole investigations from the new perspective of observational cosmology. (orig.)

Design and expected performance of a novel hybrid detector for very-high-energy gamma-ray astrophysics

Science.gov (United States)

Assis, P.; Barres de Almeida, U.; Blanco, A.; Conceição, R.; D'Ettorre Piazzoli, B.; De Angelis, A.; Doro, M.; Fonte, P.; Lopes, L.; Matthiae, G.; Pimenta, M.; Shellard, R.; Tomé, B.

2018-05-01

Current detectors for Very-High-Energy γ-ray astrophysics are either pointing instruments with a small field of view (Cherenkov telescopes), or large field-of-view instruments with relatively large energy thresholds (extensive air shower detectors). In this article, we propose a new hybrid extensive air shower detector sensitive in an energy region starting from about 100 GeV. The detector combines a small water-Cherenkov detector, able to provide a calorimetric measurement of shower particles at ground, with resistive plate chambers which contribute significantly to the accurate shower geometry reconstruction. A full simulation of this detector concept shows that it is able to reach better sensitivity than any previous gamma-ray wide field-of-view experiment in the sub-TeV energy region. It is expected to detect with a 5σ significance a source fainter than the Crab Nebula in one year at 100 GeV and, above 1 TeV a source as faint as 10% of it. As such, this instrument is suited to detect transient phenomena making it a very powerful tool to trigger observations of variable sources and to detect transients coupled to gravitational waves and gamma-ray bursts.

Low energy neutrino astrophysics with the large liquid-scintillator detector LENA

International Nuclear Information System (INIS)

Wurm, M.; Feilitzsch, F. von; Goeger-Neff, M.; Undagoitia, T. Marrodan; Oberauer, L.; Potzel, W.; Winter, J.

2007-01-01

The large-volume liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) will cover a broad field of physics. Apart from the detection of terrestrial and artificial neutrinos, and the search for proton decay, important contributions can be made to the astrophysics of stars by high-precision spectroscopy of low-energetic solar neutrinos and by the observation of neutrinos emitted by a galactic supernova. Moreover, the detection of the diffuse supernova neutrino background in LENA will offer the opportunity of studying both supernova core-collapse models and the supernova rate on cosmological timescales (z e events in an almost background-free energy window from ∼10 to 25 MeV. The search for such rare low-energetic events takes advantage of the high energy resolution and excellent background rejection possible in the LENA detector

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

International Nuclear Information System (INIS)

Sgrò, C.

2016-01-01

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

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

Science.gov (United States)

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

Visible light photon counters (VLPCs) for high rate tracking medical imaging and particle astrophysics

International Nuclear Information System (INIS)

Atac, M.

1998-02-01

This paper is on the operation principles of the Visible Light Photon Counters (VLPCs), application to high luminosity-high multiplicity tracking for High Energy Charged Particle Physics, and application to Medical Imaging and Particle Astrophysics. The VLPCs as Solid State Photomultipliers (SSPMS) with high quantum efficiency can detect down to single photons very efficiently with excellent time resolution and high avalanche gains

Studying astrophysical reactions with low-energy RI beams at CRIB

Directory of Open Access Journals (Sweden)

Yamaguchi H.

2016-01-01

Full Text Available Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the radioactive-isotope (RI beams at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study (CNS, the University of Tokyo. A typical measurement performed at CRIB is the elastic resonant scattering with the inverse kinematics. One recent experiment was on the α resonant scattering with 7Li and 7Be beams. This study is related to the astrophysical 7Li/7Be(α,γ reactions, important at hot p-p chain and νp-process in supernovae. There have also been measurements based on other experimental methods. The first THM measurement using an RI beam has been performed at CRIB, to study the 18F(p, α15O reaction at astrophysical energies via the three body reaction 2H(18F, α15On. The 18F(p, α 15O reaction rate is crucial to understand the 511-keV γ-ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

Very high energy gamma ray astrophysics

International Nuclear Information System (INIS)

Lamb, R.C.; Lewis, D.A.

1991-01-01

The Whipple Observatory High Resolution Camera will be used in a vigorous program of observations to search for new sources of very-high-energy gamma rays. In addition, a search for antimatter using the moon-earth system as an ion spectrometer will be begun. The first phase of GRANITE, the new 37-element 11-m camera, will be concluded with first light scheduled for September, 1991. The two cameras will operate in support of the Gamma Ray Observatory mission in the winter of 1991/2

Unification and extension of the similarity scaling criteria and mixing transition for studying astrophysics using high energy density laboratory experiments or numerial simulations

Energy Technology Data Exchange (ETDEWEB)

Zhou, Y

2006-08-21

The Euler similarity criteria for laboratory experiments and time-dependent mixing transition are important concepts introduced recently for application to prediction and analysis of astrophysical phenomena. However Euler scaling by itself provides no information on the distinctive spectral range of high Reynolds number turbulent flows found in astrophysics situations. On the other hand, time-dependent mixing transition gives no indication on whether a flow that just passed the mixing transition is sufficient to capture all of the significant dynamics of the complete astrophysical spectral range. In this paper, a new approach, based on additional insight gained from review of Navier-Stokes turbulence theory, is developed. It allows for revelations about the distinctive spectral scale dynamics associated with high Reynolds number astrophysical flows. From this perspective, we caution that the energy containing range of the turbulent flow measured in a laboratory setting must not be unintentionally contaminated in such a way that the interactive influences of this spectral scale range in the corresponding astrophysical situation cannot be faithfully represented. In this paper we introduce the concept of a minimum state as the lowest Reynolds number turbulent flow that a time-dependent mixing transition must achieve to fulfill this objective. Later in the paper we show that the Reynolds number of the minimum state may be determined as 1.6 x 10{sup 5}. Our efforts here can be viewed as a unification and extension of the concepts of both similarity scaling and transient mixing transition concepts. At the last the implications of our approach in planning future intensive laser experiments or massively parallel numerical simulations are discussed. A systematic procedure is outlined so that as the capabilities of the laser interaction experiments and supporting results from detailed numerical simulations performed in recently advanced supercomputing facilities increase

Unification and extension of the similarity scaling criteria and mixing transition for studying astrophysics using high energy density laboratory experiments or numerical simulations

International Nuclear Information System (INIS)

Zhou Ye

2007-01-01

The Euler similarity criteria for laboratory experiments and time-dependent mixing transition are important concepts introduced recently for application to prediction and analysis of astrophysical phenomena. However, Euler scaling by itself provides no information on the distinctive spectral range of high Reynolds number turbulent flows found in astrophysics situations. On the other hand, time-dependent mixing transition gives no indication on whether a flow that just passed the mixing transition is sufficient to capture all of the significant dynamics of the complete astrophysical spectral range. In this paper, a new approach, based on additional insight gained from review of Navier-Stokes turbulence theory, is developed. It allows for revelations about the distinctive spectral scale dynamics associated with high Reynolds number astrophysical flows. From this perspective, the energy-containing range of the turbulent flow measured in a laboratory setting must not be unintentionally contaminated in such a way that the interactive influences of this spectral scale range in the corresponding astrophysical situation cannot be faithfully represented. In this paper, the concept of a minimum state is introduced as the lowest Reynolds number turbulent flow that a time-dependent mixing transition must achieve to fulfill this objective. Later in the paper, the Reynolds number of the minimum state is determined as 1.6x10 5 . The temporal criterion for the minimum state is also obtained. The efforts here can be viewed as a unification and extension of the concepts of both similarity scaling and transient mixing transition concepts. Finally, the implications of our approach in planning future intensive laser experiments or massively parallel numerical simulations are discussed. A systematic procedure is outlined so that as the capabilities of the laser interaction experiments and supporting results from detailed numerical simulations performed in recently advanced

12th Italian-Korean Symposium on Relativistic Astrophysics

International Nuclear Information System (INIS)

Won Lee, Hyung; Remo Riffini; Vereshchagin

2013-01-01

This series of biannual symposia, since 1987, has been boosting exchange of information and collaborations between Italian and Korean astrophysicists on new and hot issues in the field of Relativistic Astrophysics. These symposia cover relativistic field theories, astrophysics and cosmology, topics such as gamma-ray bursts and compact stars, high energy cosmic rays, dark energy and dark matter, general relativity, black holes, and new physics related to cosmology. The organizers are confident that this symposium could deepen the understanding of not only astrophysics and cosmology but also Eastern and Western cultures.

14th International School of Cosmic Ray Astrophysics

CERN Document Server

Stanev, Todor; Wefel, John P; Neutrinos and explosive events in the universe

2005-01-01

This volume contains the Lectures and selected participant contributions to the 14th Course of the International School of Cosmic Rays Astrophysics, a NATO Advanced Study Institute. Well known astrophysicists and astronomers discuss different aspects of the generation of high energy signals in powerful astrophysical objects concentrating on the production of neutrinos and gamma rays from high energy particle interactions. Recent results from new experiments and observatories are presented. Topics cover a wide range including the Spitzer infrared observatory, TeV gamma ray observations, dark matter, and neutrino telescopes. The combination of basic knowledge about the production of high energy signals with information about the data analysis of ongoing observations places the book between the usual levels of a textbook and a conference proceedings. It will give the reader a good introduction to the current field of astroparticle physics, and some of the fascinating astrophysics being addressed.

Origin of a maximum of the astrophysical S factor in heavy-ion fusion reactions at deep subbarrier energies

Science.gov (United States)

Hagino, K.; Balantekin, A. B.; Lwin, N. W.; Thein, Ei Shwe Zin

2018-03-01

The hindrance phenomenon of heavy-ion fusion cross sections at deep subbarrier energies often accompanies a maximum of an astrophysical S factor at a threshold energy for fusion hindrance. We argue that this phenomenon can naturally be explained when the fusion excitation function is fitted with two potentials, with a larger (smaller) logarithmic slope at energies lower (higher) than the threshold energy. This analysis clearly suggests that the astrophysical S factor provides a convenient tool to analyze the deep subbarrier hindrance phenomenon, even though the S factor may have a strong energy dependence for heavy-ion systems unlike that for astrophysical reactions.

High-energy solar flare observations at the Y2K maximum

Science.gov (United States)

Emslie, A. Gordon

2000-04-01

Solar flares afford an opportunity to observe processes associated with the acceleration and propagation of high-energy particles at a level of detail not accessible in any other astrophysical source. I will review some key results from previous high-energy solar flare observations, including those from the Compton Gamma-Ray Observatory, and the problems that they pose for our understanding of energy release and particle acceleration processes in the astrophysical environment. I will then discuss a program of high-energy observations to be carried out during the upcoming 2000-2001 solar maximum that is aimed at addressing and resolving these issues. A key element in this observational program is the High Energy Solar Spectroscopic Imager (HESSI) spacecraft, which will provide imaging spectroscopic observations with spatial, temporal, and energy resolutions commensurate with the physical processes believed to be operating, and will in addition provide the first true gamma-ray spectroscopy of an astrophysical source. .

Hydrodynamic instabilities in astrophysics and ICF

International Nuclear Information System (INIS)

Paul Drake, R.

2005-01-01

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

The new astrophysics

International Nuclear Information System (INIS)

Longair, M.

1989-01-01

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

Recent astrophysical applications of the Trojan Horse Method to nuclear astrophysics

International Nuclear Information System (INIS)

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

2008-01-01

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

Indirect techniques in nuclear astrophysics

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-04-04

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

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

International Nuclear Information System (INIS)

Arcones, Almudena; Bardayan, Dan W.

2016-01-01

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

INTEGRAL highlights in the high energy astrophysics panorama

Energy Technology Data Exchange (ETDEWEB)

Ubertini, P.; Bazzano, A.

2013-10-15

ESAs INTEGRAL Space Observatory has spent his first decade in orbit, and its scientific outcome has completely changed our view of the hard-X/soft γ-ray sky. The scientific result comprises, among other discoveries, the production of the all-sky high energy sources catalogue, confirming the time variability over all time scales of most of the soft γ-ray sources observed, the first detailed map of the Aluminium and 511 keV annihilation line in the Galaxy and the evidence of polarized γ-ray emission from the Crab Nebula and Cyg X-1. This paper will review the latest INTEGRAL discoveries in the framework of the high energy sky panorama.

Robotic telescopes for high energy astrophysics in Ondřejov

Czech Academy of Sciences Publication Activity Database

Nekola, Martin; Hudec, René; Jelínek, M.; Kocka, Matúš; Münz, F.; Kubánek, P.; Polášek, Cyril; Šimon, Vojtěch; Štrobl, Jan

2010-01-01

Roč. 28, č. 1 (2010), s. 79-85 ISSN 0922-6435. [400 Years of Astronomical Telescopes: A Review of History, Science and Technology. Noordwijk, 29.09.2008-02.10.2008] R&D Projects: GA ČR GA205/08/1207 Grant - others:ESA(XE) ESA-PECS project No. 98023 Institutional research plan: CEZ:AV0Z10030501 Keywords : robotic telescopes * BART * D50 Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.140, year: 2010

Nuclear astrophysics lessons from INTEGRAL.

Science.gov (United States)

Diehl, Roland

2013-02-01

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

Astrophysical hints of axion-like particles

Science.gov (United States)

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

2015-01-01

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

Neutrino particle astrophysics: status and outlook

CERN Multimedia

CERN. Geneva

2016-01-01

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

Nuclear Astrophysics Experiments at CIAE

International Nuclear Information System (INIS)

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

2005-01-01

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

Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

CERN Document Server

Carraminana, Alberto

2007-01-01

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

WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

Energy Technology Data Exchange (ETDEWEB)

Mendygral, P. J.; Radcliffe, N.; Kandalla, K. [Cray Inc., St. Paul, MN 55101 (United States); Porter, D. [Minnesota Supercomputing Institute for Advanced Computational Research, Minneapolis, MN USA (United States); O’Neill, B. J.; Nolting, C.; Donnert, J. M. F.; Jones, T. W. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Edmon, P., E-mail: pjm@cray.com, E-mail: nradclif@cray.com, E-mail: kkandalla@cray.com, E-mail: oneill@astro.umn.edu, E-mail: nolt0040@umn.edu, E-mail: donnert@ira.inaf.it, E-mail: twj@umn.edu, E-mail: dhp@umn.edu, E-mail: pedmon@cfa.harvard.edu [Institute for Theory and Computation, Center for Astrophysics, Harvard University, Cambridge, MA 02138 (United States)

2017-02-01

We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.

WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

International Nuclear Information System (INIS)

Mendygral, P. J.; Radcliffe, N.; Kandalla, K.; Porter, D.; O’Neill, B. J.; Nolting, C.; Donnert, J. M. F.; Jones, T. W.; Edmon, P.

2017-01-01

We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.

Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

NARCIS (Netherlands)

Ando, S.; Baret, B.; Bartos, I.; Bouhou, B.; Chassande-Mottin, E.; Corsi, A.; Di Palma, I.; Dietz, A.; Donzaud, C.; Eichler, D.; Finley, C.; Guetta, D.; Halzen, F.; Jones, G.; Kandhasamy, S.; Kotake, K.; Kouchner, A.; Mandic, V.; Márka, S.; Márka, Z.; Moscoso, L.; Papa, M.A.; Piran, T.; Pradier, T.; Romero, G.E.; Sutton, P.; Thrane, E.; van Elewyck, V.; Waxman, E.

2013-01-01

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic

The Astrophysical Multimessenger Observatory Network (AMON)

Science.gov (United States)

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

Magnetic Reconnection in Extreme Astrophysical Environments

Science.gov (United States)

Uzdensky, Dmitri

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

Proceedings of progress in high energy physics

International Nuclear Information System (INIS)

Pauchy Hwang, W.Y.; Lee, S.C.; Lee, C.E.; Ernst, D.J.

1991-01-01

This book contains the proceedings of progress in high energy physics. Topics covered include: Particle Phenomology; Particles and Fields; Physics in 2 and 1 Dimensions; Cosmology, Astrophysics, and Gravitation; Some Perspertives on the Future of Particle Physics

Explanation for the Low Flux of High Energy Astrophysical Muon Neutrinos

International Nuclear Information System (INIS)

Pakvasa, Sandip; Joshipura, Anjan; Mohanty, Subhendra

2014-01-01

There has been some concern about the unexpected paucity of cosmic high energy muon neutrinos in detectors probing the energy region beyond 1 PeV. As a possible solution we consider the possibility that some exotic neutrino property is responsible for reducing the muon neutrino flux at high energies from distant sources; specifically, we consider: (i) neutrino decay and (ii) neutrinos being pseudo-Dirac particles. This would provide a mechanism for the reduction of high energy muon events in the IceCube detector, for example

High-energy astrophysics and the search for sources of gravitational waves

Science.gov (United States)

O'Brien, P. T.; Evans, P.

2018-05-01

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources-gamma-ray bursts (GRBs)-have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star-black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era. This article is part of a discussion meeting issue `The promises of gravitational-wave astronomy'.

Atmospheric and astrophysical Neutrinos above 1 TeV Interacting in IceCube

DEFF Research Database (Denmark)

Aartsen, M.G.; Ackermann, M.; Adam, J.

2015-01-01

The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV-PeV) neutrinos produced in distant astrophysical objects. A search for ≳100  TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos...... the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to a deposited energy of 10 TeV. From these data we derive new constraints...... on the diffuse astrophysical neutrino spectrum, Φ_ν=2.06_{-0.3}^{+0.4}×10-18(E_ν/10^5  GeV)^{-2.46±0.12} GeV^-1 cm^−2 sr^−1 s^-1 for 25  TeV

Radiative capture of nucleons at astrophysical energies with single-particle states

International Nuclear Information System (INIS)

Huang, J.T.; Bertulani, C.A.; Guimaraes, V.

2010-01-01

Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.

One-point fluctuation analysis of the high-energy neutrino sky

DEFF Research Database (Denmark)

Feyereisen, Michael R.; Tamborra, Irene; Ando, Shin'ichiro

2017-01-01

We perform the first one-point fluctuation analysis of the high-energy neutrino sky. This method reveals itself to be especially suited to contemporary neutrino data, as it allows to study the properties of the astrophysical components of the high-energy flux detected by the IceCube telescope, even...

High-energy astrophysics and the search for sources of gravitational waves.

Science.gov (United States)

O'Brien, P T; Evans, P

2018-05-28

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources-gamma-ray bursts (GRBs)-have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star-black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'. © 2018 The Author(s).

Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

Science.gov (United States)

Takabe, Hideaki

2016-10-01

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

Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs

Energy Technology Data Exchange (ETDEWEB)

Hell, Natalie [Friedrich Alexander Univ., Erlangen (Germany)

2017-03-15

K-shell transitions in astrophysically abundant metals and L-shell transitions in Fe group elements show characteristic signatures in the soft X-ray spectrum in the energy range 0.1–10 keV. These signatures have great diagnostic value for plasma parameters such as electron and ion temperatures and densities, and can thus help understand the physics controlling the energetic processes in astrophysical sources. This diagnostic power increases with advances in spectral resolution and effective area of the employed X-ray observatories. However, to make optimal use of the diagnostic potential – whether through global spectral modeling or through diagnostics from local modeling of individual lines – the underlying atomic physics has to be complete and well known. With the next generation of soft X-ray observatories featuring micro-calorimeters such as the SXS on Astro- H/Hitomi and the X-IFU on Athena, broadband high-resolution spectroscopy with large effective area will become more commonly available in the next decade. With these spectrometers, the accuracy of the plasma parameters derived from spectral modeling will be limited by the uncertainty of the reference atomic data rather than by instrumental factors, as is sometimes already the case for the high-resolution grating observations with Chandra-HETG and XMM-Newton-RGS. To take full advantage of the measured spectra, assessment of the accuracy of and improvements to the available atomic reference data are therefore important. Dedicated measurements in the laboratory are essential to benchmark the theoretical calculations providing the bulk of the reference data used in astrophysics. Experiments at the Lawrence Livermore National Laboratory electron beam ion traps (EBIT-I and SuperEBIT) have a long history of providing this service. In this work, I present new measurements of transition energies and absolute electron impact excitation cross sections geared towards currently open atomic physics data needs.

Nuclear interactions of high energy heavy ions and applications in astrophysics. Final technical report

International Nuclear Information System (INIS)

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

1998-01-01

Projectile fragmentation experiments have been conducted at the LBL Bevalac accelerator, utilizing both the B40 and the HISS facilities, to produce a dataset of 36 beam/energy combinations covering projectiles from 4 He to 58 Ni and various energies from 170--2100 MeV/nucleon. While some runs were subject to beam instabilities, magnet problems or low statistics, there remains a large dataset which is still being analyzed. The results will be used to investigate the physics of the intermediate energy fragmentation process and will find application in the astrophysics of cosmic ray propagation in the galaxy. An overview of the science goals and rationale is followed by presentation of the experimental techniques and apparatus that has been employed. Data analysis, including both detector subsystem and accelerator calibration, is discussed with emphasis on the unique features of the dataset and the analysis problems being addressed. Results from the experiments are presented throughout to illustrate the status of the analysis, e.g., momentum distribution widths. Total, Elemental and Isotopic cross sections from various beam/energy combinations are presented, including the first data on 32 S fragmentation and the complete isotopic fragmentation cross sections for 28 Si interacting in both Carbon and Hydrogen targets. The new results are compared to any existing data and to formulae used to predict unmeasured cross sections. The size and complexity of the dataset and the required detail of the analysis precluded finishing the full analysis under the subject grant. Plans for additional analysis are presented, and these will be carried out in coming years as time and resources permit

Testing Special Relativity at High Energies with Astrophysical Sources

Science.gov (United States)

Stecker, F. W.

2007-01-01

Since the group of Lorentz boosts is unbounded, there is a question as to whether Lorentz invariance (LI) holds to infinitely short distances. However, special and general relativity may break down at the Planck scale. Various quantum gravity scenarios such as loop quantum gravity, as well as some forms of string theory and extra dimension models may imply Lorentz violation (LV) at ultrahigh energies. The Gamma-Ray Large Area Space Telescope (GLAST), to be launched in mid-December, will measure the spectra of distant extragalactic sources of high energy gamma-rays, particularly active galactic nuclei and gamma-ray bursts. GLAST can look for energy-dependent gamma-ray propagation effects from such sources as a signal of Lorentz invariance violation. These sources may also exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions with low energy photons having a flux level as determined by various astronomical observations. With LV the threshold for such interactions can be significantly raised, changing the predicted absorption turnover in the observed spectrum of the sources. Stecker and Glashow have shown that the existence such absorption features in the spectra of extragalactic sources puts constraints on LV. Such constraints have important implications for some quantum gravity and large extra dimension models. Future spaceborne detectors dedicated to measuring gamma-ray polarization can look for birefringence effects as a possible signal of loop quantum gravity. A very small LV may also result in the modification or elimination of the GZK effect, thus modifying the spectrum of ultrahigh energy cosmic rays. This possibility can be explored with ground-based arrays such as Auger or with a space based detector system such as the proposed OWL satellite mission.

Nuclear astrophysics at DRAGON

International Nuclear Information System (INIS)

Hager, U.

2014-01-01

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

Model-based Clustering of High-Dimensional Data in Astrophysics

Science.gov (United States)

Bouveyron, C.

2016-05-01

The nature of data in Astrophysics has changed, as in other scientific fields, in the past decades due to the increase of the measurement capabilities. As a consequence, data are nowadays frequently of high dimensionality and available in mass or stream. Model-based techniques for clustering are popular tools which are renowned for their probabilistic foundations and their flexibility. However, classical model-based techniques show a disappointing behavior in high-dimensional spaces which is mainly due to their dramatical over-parametrization. The recent developments in model-based classification overcome these drawbacks and allow to efficiently classify high-dimensional data, even in the "small n / large p" situation. This work presents a comprehensive review of these recent approaches, including regularization-based techniques, parsimonious modeling, subspace classification methods and classification methods based on variable selection. The use of these model-based methods is also illustrated on real-world classification problems in Astrophysics using R packages.

Nuclear astrophysics

International Nuclear Information System (INIS)

Lehoucq, Roland; Klotz, Gregory

2015-11-01

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

Astrophysics at nTOF facility

International Nuclear Information System (INIS)

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

2009-01-01

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

Experimental studies of nuclear astrophysics

International Nuclear Information System (INIS)

He Jianjun; Zhou Xiaohong; Zhang Yuhu

2013-01-01

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

The Future of Gamma Ray Astrophysics

CERN Multimedia

CERN. Geneva

2016-01-01

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

Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

International Nuclear Information System (INIS)

Sedrati, R.; Attallah, R.

2014-01-01

In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data

Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

Energy Technology Data Exchange (ETDEWEB)

Sedrati, R., E-mail: rafik.sedrati@univ-annaba.org; Attallah, R.

2014-04-01

In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data.

[High energy particle physics at Purdue, 1990--1991

International Nuclear Information System (INIS)

Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1991-05-01

Progress made in the experimental and theoretical high energy physics program is reviewed. The CLEO experiment, particle astrophysics, dynamical symmetry breaking in gauge theories, the Collider Detector at Fermilab, the TOPAZ Experiment, and elementary particle physics beyond the standard model are included

Very high energy gamma ray astrophysics: Progress report, May 1, 1987-February 1, 1988

International Nuclear Information System (INIS)

Lamb, R.G.; Lewis, D.A.

1988-02-01

The Whipple observatory Gamma Ray Collaboration has continued to make steady progress in its development of a highly sensitive stereoscopic imaging gamma-ray telescope (known as the HERCULES project). The milestones in this year's development include: the demonstration of the success of the imaging concept with a single camera by the detection of a very weak flux of gamma rays from the Crab Nebula at a high level of statistical significance (7 sigma), the confirmation of our detection of an anomalous pulsed flux from Hercules X-1 in the summer of 1986 by two other groups; this result has serious implications for the mechanism for gamma-ray emission in this binary source. The construction and installation of the new high resolution camera on the 10 m reflector; the realistic simulation of the sensitivity of this camera as well as that of the full HERCULES system was also undertaken. These, and other highlights of this year's program at the Iowa State University and the Smithsonian Astrophysical Observatory, are discussed in this paper. 6 figs

Status of Ultra-High Energy Cosmic Rays

CERN Multimedia

CERN. Geneva

2015-01-01

I will review the recent results on Ultra-High energy cosmic rays obtained by the Auger and Telescope Array Observatories, and discuss some of the Astrophysical scenarios that could account for them, a connection with LHC results  as well as the possible connections to neutrino and gamma ray observations.

‘Firewall’ phenomenology with astrophysical neutrinos

Science.gov (United States)

Afshordi, Niayesh; Yazdi, Yasaman K.

2016-12-01

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

‘Firewall’ phenomenology with astrophysical neutrinos

International Nuclear Information System (INIS)

Afshordi, Niayesh; Yazdi, Yasaman K

2016-01-01

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

Computational Laboratory Astrophysics to Enable Transport Modeling of Protons and Hydrogen in Stellar Winds, the ISM, and other Astrophysical Environments

Science.gov (United States)

Schultz, David

As recognized prominently by the APRA program, interpretation of NASA astrophysical mission observations requires significant products of laboratory astrophysics, for example, spectral lines and transition probabilities, electron-, proton-, or heavy-particle collision data. Availability of these data underpin robust and validated models of astrophysical emissions and absorptions, energy, momentum, and particle transport, dynamics, and reactions. Therefore, measured or computationally derived, analyzed, and readily available laboratory astrophysics data significantly enhances the scientific return on NASA missions such as HST, Spitzer, and JWST. In the present work a comprehensive set of data will be developed for the ubiquitous proton-hydrogen and hydrogen-hydrogen collisions in astrophysical environments including ISM shocks, supernova remnants and bubbles, HI clouds, young stellar objects, and winds within stellar spheres, covering the necessary wide range of energy- and charge-changing channels, collision energies, and most relevant scattering parameters. In addition, building on preliminary work, a transport and reaction simulation will be developed incorporating the elastic and inelastic collision data collected and produced. The work will build upon significant previous efforts of the principal investigators and collaborators, will result in a comprehensive data set required for modeling these environments and interpreting NASA astrophysical mission observations, and will benefit from feedback from collaborators who are active users of the work proposed.

Ultra-High Energy Cosmic Rays (2/3)

CERN Multimedia

CERN. Geneva

2012-01-01

The origin of the highest energy cosmic rays (UHECR) with energies above 1000 TeV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. In these lectures we present the recent observational results from HiRes, Telescope Array and Pierre Auger Observatory as well as (some of) the possible astrophysical origins of UHECR. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

Ultra-High Energy Cosmic Rays (1/3)

CERN Multimedia

CERN. Geneva

2012-01-01

The origin of the highest energy cosmic rays (UHECR) with energies above 1000 TeV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. In these lectures we present the recent observational results from HiRes, Telescope Array and Pierre Auger Observatory as well as (some of) the possible astrophysical origins of UHECR. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

Ultra-High Energy Cosmic Rays (3/3)

CERN Multimedia

CERN. Geneva

2012-01-01

The origin of the highest energy cosmic rays (UHECR) with energies above 1000 TeV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. In these lectures we present the recent observational results from HiRes, Telescope Array and Pierre Auger Observatory as well as (some of) the possible astrophysical origins of UHECR. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data

DEFF Research Database (Denmark)

Aartsen, M.G.; Ackermann, M.; Adams, J.

2014-01-01

Cube detector are consistent with the previously reported astrophysical flux in the 100 TeV–PeV range at the level of 10^-8  GeV cm^-2 s^-1 sr^-1 per flavor and reject a purely atmospheric explanation for the combined three-year data at 5.7σ. The data are consistent with expectations for equal fluxes of all...

Analyses of High-Energy Sources with ESA Gaia

Czech Academy of Sciences Publication Activity Database

Hudec, R.; Šimon, Vojtěch; Hudcová, Věra

2010-01-01

Roč. 1248, - (2010), s. 583-584 ISSN 1551-7616. [X-ray astronomy 2009. Bologna, 07.09.2009-11.09.2009] Institutional research plan: CEZ:AV0Z10030501 Keywords : high-energy sources * gamma-ray bursts * low-dispersion spectra Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Superradiance energy extraction, black-hole bombs and implications for astrophysics and particle physics

CERN Document Server

Brito, Richard; Pani, Paolo

2015-01-01

This volume gives a unified picture of the multifaceted subject of superradiance, with a focus on recent developments in the field, ranging from fundamental physics to astrophysics. Superradiance is a radiation enhancement process that involves dissipative systems. With a 60 year-old history, superradiance has played a prominent role in optics, quantum mechanics and especially in relativity and astrophysics. In Einstein's General Relativity, black-hole superradiance is permitted by dissipation at the event horizon, which allows energy extraction from the vacuum, even at the classical level. When confined, this amplified radiation can give rise to strong instabilities known as "blackhole bombs'', which have applications in searches for dark matter, in physics beyond the Standard Model and in analog models of gravity. This book discusses and draws together all these fascinating aspects of superradiance.

Alignment error of mirror modules of advanced telescope for high-energy astrophysics due to wavefront aberrations

Science.gov (United States)

Zocchi, Fabio E.

2017-10-01

One of the approaches that is being tested for the integration of the mirror modules of the advanced telescope for high-energy astrophysics x-ray mission of the European Space Agency consists in aligning each module on an optical bench operated at an ultraviolet wavelength. The mirror module is illuminated by a plane wave and, in order to overcome diffraction effects, the centroid of the image produced by the module is used as a reference to assess the accuracy of the optical alignment of the mirror module itself. Among other sources of uncertainty, the wave-front error of the plane wave also introduces an error in the position of the centroid, thus affecting the quality of the mirror module alignment. The power spectral density of the position of the point spread function centroid is here derived from the power spectral density of the wave-front error of the plane wave in the framework of the scalar theory of Fourier diffraction. This allows the defining of a specification on the collimator quality used for generating the plane wave starting from the contribution to the error budget allocated for the uncertainty of the centroid position. The theory generally applies whenever Fourier diffraction is a valid approximation, in which case the obtained result is identical to that derived by geometrical optics considerations.

Hot topics of X-ray Astrophysics from past and future missions

International Nuclear Information System (INIS)

Costa, Enrico

2013-01-01

50 years after the first discovery, X-ray Astrophysics is a well-established discipline, with a continuous development of detection/observation techniques. These can find application on both large observatories and thematic space missions. I will recall the main milestones of X-ray Astrophysics and review some of the hottest topics of High Energy Astrophysics, included some open problems of Fundamental Physics, that can be addressed with measurements in the X-ray band. I will show which proposed missions and which concepts of new missions could be more attractive for a future development of this discipline

Nuclear astrophysics

International Nuclear Information System (INIS)

Arnould, M.; Takahashi, K.

1999-01-01

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

Nuclear astrophysics with radioactive beams

International Nuclear Information System (INIS)

Bertulani, C.A.; Gade, A.

2010-01-01

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

Searches for astrophysical neutrinos with IceCube

International Nuclear Information System (INIS)

Williams, D.

2014-01-01

Powerful astrophysical objects such as active galactic nuclei (AGN), core collapse supernovae and gamma ray bursts (GRBs) are potential sources of the highest energy cosmic rays. Many models of cosmic ray proton acceleration predict a corresponding flux of neutrinos in the TeV-PeV energy range. The detection of astrophysical neutrinos requires the largest neutrino detector ever built: IceCube, a cubic-kilometer array located near the geographic South Pole. IceCube has been collecting data throughout its construction, which was complete in December 2010. Data from the partial IceCube detector have already set interesting limits on astrophysical neutrino fluxes, including stringent limits on neutrino production in GRBs. (authors)

New and old accelerators: what can they do for astrophysics

International Nuclear Information System (INIS)

Bjorken, J.D.

1985-07-01

The quantum numbers and energy spectrum of high energy accelerators and storage rings are described, along with some ways they may contribute to astrophysical issues. Some emphasis is given to the role of relativistic heavy-ion colliders in possibly providing laboratory samples of quark-gluon plasma. 6 refs., 3 figs

Frontiers for Discovery in High Energy Density Physics

Energy Technology Data Exchange (ETDEWEB)

Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

2004-07-20

The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

Applications of the Trojan Horse method in nuclear astrophysics

Energy Technology Data Exchange (ETDEWEB)

Spitaleri, Claudio, E-mail: spitaleri@lns.infn.it [Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy and Laboratori Nazionali del Sud-INFN, Catania (Italy)

2015-02-24

The study of the energy production in stars and related nucleosyntesis processes requires increasingly precise knowledge of the nuclear reaction cross section and reaction rates at interaction energy. In order to overcome the experimental difficulties, arising from small cross-sections involved in charge particle induced reactions at astrophysical energies, and from the presence of electron screening, it was necessary to introduce indirect methods. Trough these methods it is possible to measure cross sections at very small energies and retrieve information on electron screening effect when ultra-low energy direct measurements are available. The Trojan Horse Method (THM) represents the indirect technique to determine the bare nucleus astrophysical S-factor for reactions between charged particles at astrophysical energies. The basic theory of the THM is discussed in the case of non-resonant.

Focusing Telescopes in Nuclear Astrophysics

CERN Document Server

Ballmoos, Peter von

2007-01-01

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

Trojin horse method for indirect measurement of astrophysic S factor

International Nuclear Information System (INIS)

Fu Yuanyong; Zhou Shuhua; Li Chengbo; Wen Qungang

2014-01-01

The nuclear reaction rates in the astrophysical environment are indispensable input parameters in different astrophysics theories, and play important roles in understanding the astrophysical nuclear synthesis and the evolution of the universe. However, at the astrophysical temperature, the nuclear reactions proceed at very low energies. Due to the Coulomb barrier the reaction cross sections are very small, so that the direct measurement is almost impossible. The Trojin horse theory provides a useful method to measure indirectly the low energy two body cross sections by measuring the suitable three body reactions. Some approximations are applied in the theory to get convenient formula. This paper introduces the Trojin horse theory and its application in astrophysics nuclear reactions. (authors)

Underground nuclear astrophysics at the Dresden Felsenkeller

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Excitation of compound states in the subsystems as indirect tool in nuclear astrophysics

Directory of Open Access Journals (Sweden)

Tribble R.E.

2010-03-01

Full Text Available Astrophysical reactions proceeding through compound states represent one of the crucial part of nuclear astrophysics. However, due to the presence of the Coulomb barrier, it is often very difficult or even impossible to obtain the astrophysical S (E factor from measurements in the laboratory at astrophysically relevant energies. The Trojan Horse method (THM provides a unique tool to obtain the information about resonant astrophysical reactions at astrophysically relevant energies. Here the theory and application of the THM for the resonant reactions is addressed.

High energy physics research. Final technical report, 1957--1994

International Nuclear Information System (INIS)

Williams, H.H.

1995-01-01

This is the final technical report to the Department of Energy on High Energy Physics at the University of Pennsylvania. It discusses research conducted in the following areas: neutrino astrophysics and cosmology; string theory; electroweak and collider physics; supergravity; cp violation and baryogenesis; particle cosmology; collider detector at Fermilab; the sudbury neutrino observatory; B-physics; particle physics in nuclei; and advanced electronics and detector development

High energy physics research. Final technical report, 1957--1994

Energy Technology Data Exchange (ETDEWEB)

Williams, H.H.

1995-10-01

This is the final technical report to the Department of Energy on High Energy Physics at the University of Pennsylvania. It discusses research conducted in the following areas: neutrino astrophysics and cosmology; string theory; electroweak and collider physics; supergravity; cp violation and baryogenesis; particle cosmology; collider detector at Fermilab; the sudbury neutrino observatory; B-physics; particle physics in nuclei; and advanced electronics and detector development.

Nuclear reactions in astrophysics

International Nuclear Information System (INIS)

Cardenas, M.

1976-01-01

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

New Improved Indirect Measurement of the {sup 19}F( p , α ){sup 16}O Reaction at Energies of Astrophysical Relevance

Energy Technology Data Exchange (ETDEWEB)

Indelicato, I.; La Cognata, M.; Spitaleri, C.; Cherubini, S.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Tumino, A. [INFN, Laboratori Nazionali del Sud, Catania (Italy); Burjan, V.; Hons, Z.; Kroha, V.; Mrazek, J. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Hayakawa, S. [RIKEN, CNS, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Mazzocco, M.; Strano, E.; Torresi, D., E-mail: indelicato@lns.infn.it [INFN, Sezione di Padova, Padova (Italy)

2017-08-10

Fluorine abundance determination is of great importance in stellar physics to understand s-elements production and mixing processes in asymptotic giant branch (AGB) stars. Up to now, theoretical models overproduce F abundances in AGB stars with respect to the observed values, thus calling for further investigation of the reactions involving fluorine. In particular, the {sup 19}F( p , α ){sup 16}O reaction is the main destruction channel of fluorine at the bottom of the convective envelope in AGB stars, an H-rich environment where it can experience temperatures high enough to determine its destruction, owing to additional mixing processes. In this paper the Trojan horse method (THM) was used to extract the {sup 19}F( p , α {sub 0}){sup 16}O S-factor in the energy range of astrophysical interest ( E {sub cm} ≈ 0–1 MeV). This is the most relevant channel at the low temperatures (few 10{sup 7} K) characterizing the bottom of the convective envelope, according to current knowledge. A previous indirect experiment using the THM has observed three resonances in the energy regions below E {sub cm} ≈ 450 keV. These energies correspond to typical AGB temperatures, thus implying a significant increase in the reaction rate. Statistics are scarce for performing an accurate separation between resonances, preventing one from drawing a quantitative conclusion about their total widths and spin parities. Before THM measurement, only extrapolations were available below about 500 keV, showing a non-resonant behavior that sharply contradicts the trend of the astrophysical factor at higher energies. A new experiment has been performed to verify the measured TH astrophysical factor and to perform more accurate spectroscopy of the involved resonances.

Intermediate Energies for Nuclear Astrophysics and the Development of a Position Sensitive Microstrip Detector System

Energy Technology Data Exchange (ETDEWEB)

Sobotka, Lee G. [Washington Univ., St. Louis, MO (United States); Blackmon, J. [Louisiana State Univ., Baton Rouge, LA (United States); Bertulani, C. [Texas A & M Univ., College Station, TX (United States)

2015-12-30

The chemical elements are made at astrophysical sites through a sequence of nuclear reactions often involving unstable nuclei. The overarching aim of this project is to construct a system that allows for the inverse process of nucleosynthesis (i.e. breakup of heavier nuclei into lighter ones) to be studied in high efficiency. The specific problem to be overcome with this grant is inadequate dynamic range and (triggering) threshold to detect the products of the breakup which include both heavy ions (with large energy and large deposited energy in a detector system) and protons (with little energy and deposited energy.) Early on in the grant we provided both TAMU and RIKEN (the site of the eventual experiments) with working systems based on the existing technology. This technology could be used with either an external preamplifier that was to be designed and fabricated by our RIKEN collaborators or upgraded by replacing the existing chip with one we designed. The RIKEN external preamplifier project never can to completion but our revised chip was designed, fabricated, used in a test experiment and performs as required.

2nd Workshop on the Nature of the High-Energy Unidentified Sources

CERN Document Server

Cheng, K S; Multiwavelength Approach to Unidentified Gamma-Ray Sources

2005-01-01

Nearly one half of the point-like gamma-ray sources detected by EGRET instrument of the late Compton satellite are still defeating our attempts at identifying them. To establish the origin and nature of these enigmatic sources has become a major problem of current high-energy astrophysics. The second workshop on Multiwavelength Approach to Unidentified Gamma-ray Sources intends to shed new and fresh light on the problem of the nature of these mysterious sources and the objects behind them. The proceedings contain 46 contributed papers in this subject, which cover theoretical models on gamma-ray sources as well as the best multiwavelength strategies for the identification of the promising candidates. The topics of this conference also include energetic phenomena ocurring both in galactic and extragalactic scenarios, phenomena that might lead to the appearance of what we have called high-energy unidentified sources. The book will be of interest for all active researchers in the high-energy astrophysics and rela...

Advances in instrumentation for nuclear astrophysics

Directory of Open Access Journals (Sweden)

S. D. Pain

2014-04-01

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

''DIANA'' - A New, Deep-Underground Accelerator Facility for Astrophysics Experiments

International Nuclear Information System (INIS)

Leitner, M.; Leitner, D.; Lemut, A.; Vetter, P.; Wiescher, M.

2009-01-01

The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory to build a nuclear astrophysics accelerator facility 1.4 km below ground. DIANA is part of the US proposal DUSEL (Deep Underground Science and Engineering Laboratory) to establish a cross-disciplinary underground laboratory in the former gold mine of Homestake in South Dakota, USA. DIANA would consist of two high-current accelerators, a 30 to 400 kV variable, high-voltage platform, and a second, dynamitron accelerator with a voltage range of 350 kV to 3 MV. As a unique feature, both accelerators are planned to be equipped with either high-current microwave ion sources or multi-charged ECR ion sources producing ions from protons to oxygen. Electrostatic quadrupole transport elements will be incorporated in the dynamitron high voltage column. Compared to current astrophysics facilities, DIANA could increase the available beam densities on target by magnitudes: up to 100 mA on the low energy accelerator and several mA on the high energy accelerator. An integral part of the DIANA project is the development of a high-density super-sonic gas-jet target which can handle these anticipated beam powers. The paper will explain the main components of the DIANA accelerators and their beam transport lines and will discuss related technical challenges

Large-Scale Astrophysical Visualization on Smartphones

Science.gov (United States)

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

2011-07-01

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

Extreme Transients in the High Energy Universe

Science.gov (United States)

Kouveliotou, Chryssa

2013-01-01

The High Energy Universe is rich in diverse populations of objects spanning the entire cosmological (time)scale, from our own present-day Milky Way to the re-ionization epoch. Several of these are associated with extreme conditions irreproducible in laboratories on Earth. Their study thus sheds light on the behavior of matter under extreme conditions, such as super-strong magnetic fields (in excess of 10^14 G), high gravitational potentials (e.g., Super Massive Black Holes), very energetic collimated explosions resulting in relativistic jet flows (e.g., Gamma Ray Bursts, exceeding 10^53 ergs). In the last thirty years, my work has been mostly focused on two apparently different but potentially linked populations of such transients: magnetars (highly magnetized neutron stars) and Gamma Ray Bursts (strongly beamed emission from relativistic jets), two populations that constitute unique astrophysical laboratories, while also giving us the tools to probe matter conditions in the Universe to redshifts beyond z=10, when the first stars and galaxies were assembled. I did not make this journey alone I have either led or participated in several international collaborations studying these phenomena in multi-wavelength observations; solitary perfection is not sufficient anymore in the world of High Energy Astrophysics. I will describe this journey, present crucial observational breakthroughs, discuss key results and muse on the future of this field.

CELESTE: an atmospheric Cherenkov telescope for high energy gamma astrophysics

Czech Academy of Sciences Publication Activity Database

Paré, E.; Balauge, B.; Bazer-Bachi, R.; Bergeret, H.; Berny, F.; Briand, N.; Bruel, P.; Cerutti, M.; Collon, J.; Cordier, A.; Cornbise, P.; Debiais, G.; Dezalay, J. P.; Dumora, D.; Durand, E.; Eschstruth, P.; Espigat, P.; Fabre, B.; Fleury, P.; Gilly, J.; Gouillaud, J. C.; Gregory, C.; Hérault, N.; Holder, J.; Hrabovský, Miroslav; Incerti, S.; Jouenne, A.; Kalt, L.; LeGallou, R.; Lott, B.; Manigot, P.; Neveu, J.; Olive, J. F.; Palatka, Miroslav; Perez, A.; Rebii, A.; Rob, L.; Sans, J. L.; Schovánek, Petr; Villard, G.

2002-01-01

Roč. 490, - (2002), s. 71-89 ISSN 0168-9002 R&D Projects: GA MŠk LN00A006 Institutional research plan: CEZ:AV0Z1010920 Keywords : gamma-ray astronopy * atmospheric Cherenkov detector Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.167, year: 2002

Goddard's Astrophysics Science Divsion Annual Report 2014

Science.gov (United States)

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

2015-01-01

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

Multi-scale Dynamical Processes in Space and Astrophysical Plasmas

CERN Document Server

Vörös, Zoltán; IAFA 2011 - International Astrophysics Forum 2011 : Frontiers in Space Environment Research

2012-01-01

Magnetized plasmas in the universe exhibit complex dynamical behavior over a huge range of scales. The fundamental mechanisms of energy transport, redistribution and conversion occur at multiple scales. The driving mechanisms often include energy accumulation, free-energy-excited relaxation processes, dissipation and self-organization. The plasma processes associated with energy conversion, transport and self-organization, such as magnetic reconnection, instabilities, linear and nonlinear waves, wave-particle interactions, dynamo processes, turbulence, heating, diffusion and convection represent fundamental physical effects. They demonstrate similar dynamical behavior in near-Earth space, on the Sun, in the heliosphere and in astrophysical environments. 'Multi-scale Dynamical Processes in Space and Astrophysical Plasmas' presents the proceedings of the International Astrophysics Forum Alpbach 2011. The contributions discuss the latest advances in the exploration of dynamical behavior in space plasmas environm...

Promising lines of investigations in the realms of laboratory astrophysics with the aid of powerful lasers

International Nuclear Information System (INIS)

Belyaev, V. S.; Batishchev, P. A.; Bolshakov, V. V.; Elkin, K. S.; Karabadzhak, G. F.; Kovkov, D. V.; Matafonov, A. P.; Raykunov, G. G.; Yakhin, R. A.; Pikuz, S. A.; Skobelev, I. Yu.; Faenov, A. Ya.; Fortov, V. E.; Krainov, V. P.; Rozanov, V. B.

2013-01-01

The results of work on choosing and substantiating promising lines of research in the realms of laboratory astrophysics with the aid of powerful lasers are presented. These lines of research are determined by the possibility of simulating, under laboratory conditions, problematic processes of presentday astrophysics, such as (i) the generation and evolution of electromagnetic fields in cosmic space and the role of magnetic fields there at various spatial scales; (ii) the mechanisms of formation and evolution of cosmic gamma-ray bursts and relativistic jets; (iii) plasma instabilities in cosmic space and astrophysical objects, plasma jets, and shock waves; (iv) supernova explosions and mechanisms of the explosion of supernovae featuring a collapsing core; (v) nuclear processes in astrophysical objects; (vi) cosmic rays and mechanisms of their production and acceleration to high energies; and (vii) astrophysical sources of x-ray radiation. It is shown that the use of existing powerful lasers characterized by an intensity in the range of 10 18 –10 22 W/cm 2 and a pulse duration of 0.1 to 1 ps and high-energy lasers characterized by an energy in excess of 1 kJ and a pulse duration of 1 to 10 ns makes it possible to perform investigations in laboratory astrophysics along all of the chosen promising lines. The results obtained by experimentally investigating laser plasma with the aid of the laser facility created at Central Research Institute of Machine Building (TsNIIMash) and characterized by a power level of 10 TW demonstrate the potential of such facilities for performing a number of experiments in the realms of laboratory astrophysics.

Status reports of supercomputing astrophysics in Japan

International Nuclear Information System (INIS)

Nakamura, Takashi; Nagasawa, Mikio

1990-01-01

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

The Utilization of Classifications in High-Energy Astrophysics Experiments

Science.gov (United States)

Atwood, Bill

2012-03-01

The history of high-energy gamma observations stretches back several decades. But it was with the launch of the Energetic Gamma Ray Experiment Telescope (EGRET) in 1991 onboard the Compton Gamma Ray Observatory (CGRO) [1], that the field entered a new era of discovery. At the high-energy end of the electromagnetic spectrum, incoming particles of light, photons, interact with matter mainly by producing electron-positron pairs and this process dominates above an energy of 10-30MeV depending on the material. To a high degree the directionality of the incoming gamma ray is reflected in the e+ and e-, and hence the detection of the trajectories of the e+e- pair can be used to infer the direction of the originating photon. Measuring these high-energy charged particles is the domain of high-energy particle physics and so it should be of little surprise that particle physicists played a significant role in the design and construction of EGRET, as well as the design and implementation of analysis methods for the resulting data. Prior to EGRET, only a handful of sources in the sky were known as high-energy gamma-ray emitters. During EGRET's 9-years mission the final catalog included over 270 sources including new types such as Gamma Ray Bursts (GRBs). This set the stage for the next-generation mission, the Gamma ray Large Area Space Telescope (GLAST) [2]. Very early in the EGRET mission, the realization that the high-energy gamma-ray sky was extremely interesting led to a competition to develop the next-generation instruments. The technology used in EGRET was frozen in the late 1970s and by 1992, enormous advances had been made in experimental particle physics. In particular the effort to develop solid state detectors, targeted for use at the Super Conducting Super Collider (SSC), had made the technology of silicon strip detectors (SSDs) commercially viable for use in large area arrays. Given the limitations imposed by the space environment (e.g., operate in a vacuum, scarce

Journal of Astrophysics and Astronomy

Indian Academy of Sciences (India)

27

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

Study of aluminum emission spectra in astrophysical plasmas

International Nuclear Information System (INIS)

Jin Zhan; Zhang Jie

2001-01-01

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

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... The SSC+ERC model using the external seed photons from hot dust or Broad Line Region (BLR) emission is probably favourable avoiding the extreme ... Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, China.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy; Volume 39; Issue 1. Issue front cover thumbnail. Volume 39, Issue 1. February 2018. Article ID 1. Editorial · Samir Mandal Indranil Chattopadhyay Anuj Nandi Santabrata Das · More Details Abstract Fulltext PDF. Article ID 2 Review. High energy transients: The ...

Hera: High Energy Astronomical Data Analysis via the Internet

Science.gov (United States)

Valencic, Lynne A.; Chai, P.; Pence, W.; Snowden, S.

2011-09-01

The HEASARC at NASA Goddard Space Flight Center has developed Hera, a data processing facility for analyzing high energy astronomical data over the internet. Hera provides all the software packages, disk space, and computing resources needed to do general processing of and advanced research on publicly available data from High Energy Astrophysics missions. The data and data products are kept on a server at GSFC and can be downloaded to a user's local machine. This service is provided for free to students, educators, and researchers for educational and research purposes.

Astrophysical constraints on Planck scale dissipative phenomena.

Science.gov (United States)

Liberati, Stefano; Maccione, Luca

2014-04-18

The emergence of a classical spacetime from any quantum gravity model is still a subtle and only partially understood issue. If indeed spacetime is arising as some sort of large scale condensate of more fundamental objects, then it is natural to expect that matter, being a collective excitation of the spacetime constituents, will present modified kinematics at sufficiently high energies. We consider here the phenomenology of the dissipative effects necessarily arising in such a picture. Adopting dissipative hydrodynamics as a general framework for the description of the energy exchange between collective excitations and the spacetime fundamental degrees of freedom, we discuss how rates of energy loss for elementary particles can be derived from dispersion relations and used to provide strong constraints on the base of current astrophysical observations of high-energy particles.

High energy neutrino astronomy; past, present and future

International Nuclear Information System (INIS)

Learned, J.G.

1993-01-01

The nascent field of high energy neutrino astronomy seems to be near to blossoming in the next few years, after decades of speculation and preliminary experimental work. The motivation for the endeavor, anticipated types of sources, consideration of energy regime for first attempts, scale size needed, and techniques are qualitatively reviewed. A summary of relevant current projects is presented with emphasis on the new initiatives with detectors of the 10,000m 2 class. It seems that by the end of the decade there may be a few such new generation instruments in operation, and that with luck the business of high energy neutrino astrophysics will be underway by the turn of the century. (orig.)

Theoretically palatable flavor combinations of astrophysical neutrinos

International Nuclear Information System (INIS)

Bustamante, Mauricio

2015-07-01

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

The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

Energy Technology Data Exchange (ETDEWEB)

Cognata, M. La; Pizzone, R. G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Spitaleri, C.; Cherubini, S.; Romano, S. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Gulino, M.; Tumino, A. [Kore University, Enna, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

2014-05-09

Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

International Nuclear Information System (INIS)

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

2014-01-01

Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance

Probing the nuclear symmetry energy at high densities with nuclear reactions

Science.gov (United States)

Leifels, Y.

2017-11-01

The nuclear equation of state is a topic of highest current interest in nuclear structure and reactions as well as in astrophysics. The symmetry energy is the part of the equation of state which is connected to the asymmetry in the neutron/proton content. During recent years a multitude of experimental and theoretical efforts on different fields have been undertaken to constraint its density dependence at low densities but also above saturation density (ρ_0=0.16 fm ^{-3} . Conventionally the symmetry energy is described by its magnitude S_v and the slope parameter L , both at saturation density. Values of L = 44 -66MeV and S_v=31 -33MeV have been deduced in recent compilations of nuclear structure, heavy-ion reaction and astrophysics data. Apart from astrophysical data on mass and radii of neutron stars, heavy-ion reactions at incident energies of several 100MeV are the only means do access the high density behaviour of the symmetry energy. In particular, meson production and collective flows upto about 1 AGeV are predicted to be sensitive to the slope of the symmetry energy as a function of density. From the measurement of elliptic flow of neutrons with respect to charged particles at GSI, a more stringent constraint for the slope of the symmetry energy at supra-saturation densities has been deduced. Future options to reach even higher densities will be discussed.

A New ECR Ion Source for Nuclear Astrophysics Studies

Science.gov (United States)

Cesaratto, John M.

2008-10-01

The Laboratory for Experimental Nuclear Astrophysics (LENA) is a low energy facility designed to study nuclear reactions of astrophysical interest at energies which are important for nucleosysthesis. In general, these reactions have extremely small cross sections, requiring intense beams and efficient detection systems. Recently, a new, high intensity electron-cyclotron-resonance (ECR) ion source has been constructed (based on a design by Wills et al.[1]), which represents a substantial improvement in the capabilities of LENA. Beam is extracted from an ECR plasma excited at 2.45 GHz and confined by an array of permanent magnets. It has produced H^+ beams in excess of 1 mA on target over the energy range 100 - 200 keV, which greatly increases our ability to measure small cross sections. Initial measurements will focus on the ^23Na(p,γ)^24Mg reaction, which is of interest in a variety of astrophysical scenarios. The present uncertainty in the rate of this reaction is the result of an unobserved resonance expected at Elab =144 keV, which should be detectable using beams from the new ECR source. In collaboration with Arthur E. Champagne and Thomas B. Clegg, University of North Carolina, Chapel Hill and TUNL. [3pt] [1] J. S. C. Wills et al., Rev. Sci. Instrum. 69, 65 (1999).

Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory

Energy Technology Data Exchange (ETDEWEB)

Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

2009-06-01

These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for sidereal modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.

1996 European school of high-energy physics. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Ellis, N; Neubert, M [eds.

1997-07-02

The European School of High-Energy Physics is intended to give young experimental physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on Field Theory, Physics Beyond the Standard Model, Flavour Physics, Neutrino Physics, Collider Physics and Astrophysics, as well as reports on Heavy-Ion Physics, the Large Hadron Collider Project and Physics in JINR/Russia. (orig.)

1996 European school of high-energy physics. Proceedings

International Nuclear Information System (INIS)

Ellis, N.; Neubert, M.

1997-01-01

The European School of High-Energy Physics is intended to give young experimental physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on Field Theory, Physics Beyond the Standard Model, Flavour Physics, Neutrino Physics, Collider Physics and Astrophysics, as well as reports on Heavy-Ion Physics, the Large Hadron Collider Project and Physics in JINR/Russia. (orig.)

Global kinetic theory of astrophysical jets

International Nuclear Information System (INIS)

Chang, T.

1989-01-01

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

High density plasmas formation in Inertial Confinement Fusion and Astrophysics

International Nuclear Information System (INIS)

Martinez-Val, J. M.; Minguez, E.; Velarde, P.; Perlado, J. M.; Velarde, G.; Bravo, E.; Eliezer, S.; Florido, R.; Garcia Rubiano, J.; Garcia-Senz, D.; Gil de la Fe, J. M.; Leon, P. T.; Martel, P.; Ogando, F.; Piera, M.; Relano, A.; Rodriguez, R.; Garcia, C.; Gonzalez, E.; Lachaise, M.; Oliva, E.

2005-01-01

In inertially confined fusion (ICF), high densities are required to obtain high gains. In Fast Ignition, a high density, low temperature plasma can be obtained during the compression. If the final temperature reached is low enough, the electrons of the plasma can be degenerate. In degenerate plasmas. Bremsstrahlung emission is strongly suppressed an ignition temperature becomes lower than in classical plasmas, which offers a new design window for ICF. The main difficulty of degenerate plasmas in the compression energy needed for high densities. Besides that, the low specific heat of degenerate electrons (as compared to classical values) is also a problem because of the rapid heating of the plasma. Fluid dynamic evolution of supernovae remnants is a very interesting problem in order to predict the thermodynamical conditions achieved in their collision regions. Those conditions have a strong influence in the emission of light and therefore the detection of such events. A laboratory scale system has been designed reproducing the fluid dynamic field in high energy experiments. The evolution of the laboratory system has been calculated with ARWEN code, 2D Radiation CFD that works with Adaptive Mesh Refinement. Results are compared with simulations on the original system obtained with a 3D SPH astrophysical code. New phenomena at the collision plane and scaling of the laboratory magnitudes will be described. Atomic physics for high density plasmas has been studied with participation in experiments to obtain laser produced high density plasmas under NLTE conditions, carried out at LULI. A code, ATOM3R, has been developed which solves rate equations for optically thin plasmas as well as for homogeneous optically thick plasmas making use of escape factors. New improvements in ATOM3R are been done to calculate level populations and opacities for non homogeneous thick plasmas in NLTE, with emphasis in He and H lines for high density plasma diagnosis. Analytical expression

Traversable braneworld wormholes supported by astrophysical observations

Science.gov (United States)

Wang, Deng; Meng, Xin-He

2018-02-01

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

LAD Early Career Prize Talk:Laboratory astrophysics experiments investigating the effects of high energy fluxes on Rayleigh-Taylor instability growth relevant to young supernova remnants

Science.gov (United States)

Kuranz, Carolyn C.; Drake, R. Paul; Park, Hye Sook; Huntington, Channing; Miles, Aaron R.; Remington, Bruce A.; Plewa, Tomek; Trantham, Matt; Shvarts, Dov; Raman, Kumar; MacLaren, Steven; Wan, Wesley; Doss, Forrest; Kline, John; Flippos, Kirk; Malamud, Guy; Handy, Timothy; Prisbey, Shon; Grosskopf, Michael; Krauland, Christine; Klein, Sallee; Harding, Eric; Wallace, Russell; Marion, Donna; Kalantar, Dan

2017-06-01

Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh Taylor (RT) instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter (CSM), based on simple models and hydrodynamic simulations. When a blast wave emerges from an exploding star, it drives a forward shock into the CSM and a reverse shock forms in the expanding stellar ejecta, creating a young supernova remnant (SNR). As mass accumulates in the shocked layers, the interface between these two shocks decelerates, becoming unstable to the RT instability. Simulations predict that RT produces structures at this interface, having a range of spatial scales. When the CSM is dense enough, as in the case of SN 1993J, the hot shocked matter can produce significant radiative fluxes that affect the emission from the SNR. Here we report experimental results from the National Ignition Facility (NIF) to explore how large energy fluxes, which are present in supernovae such as SN 1993J, might affect this structure. The experiment used NIF to create a RT unstable interface subject to a high energy flux by the emergence of a blast wave into lower-density matter, in analogy to the SNR. We also preformed and with a low energy flux to compare the affect of the energy flux on the instability growth. We found that the RT growth was reduced in the experiments with a high energy flux. In analyzing the comparison with SN 1993J, we discovered that the energy fluxes produced by heat conduction appear to be larger than the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling SNRs.

Comments on pulses of characteristic energy produced in solar flare detonations and its possible application to other astrophysical plasmas

Energy Technology Data Exchange (ETDEWEB)

Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

1977-06-01

A qualitative discussion of physical conditions at neutral sheets was developed in an attempt to explain the repetitive pulsed energy-production mechanism, which has been suggested for solar flares. A characteristic energy per pulse appears to depend critically on the magnetic field strength and dipole length applied to a high temperature plasma, and seem to be regulated by discrete characteristic relative changes in the magnetic moment, following Syrovatskii's model. Discrete energy pulses are produced when neutral sheet thickness approaches to critical values, proportional to the characteristic relative changes in the magnetic moment. Repetition of pulses may occur in multi-sheet configurations as magnetically complex active centres, or at a single sheet where the total system energy change exceeds the critical conditions. The time-scale of the pulsed energy release may be explained by the tearing mode instability, and the repetition time-scale might be understood by the Sweet mechanism in limit conditions. The mechanism might have attractive applications in other high temperature astrophysical plasmas. An empirical relation is derived for pulses' energy prediction, in orders of magnitude, and some possible tests were suggested. An attempt was made to interpret soft ..gamma..-ray events of cosmic origin.

Comments on pulses of characteristic energy produced in solar flare detonations and its possible application to other astrophysical plasmas

International Nuclear Information System (INIS)

Kaufmann, P.

1977-01-01

A qualitative discussion of physical conditions at neutral sheets was developed in an attempt to explain the repetitive pulsed energy-production mechanism, which has been suggested for solar flares. A characteristic energy per pulse appears to depend critically on the magnetic field strength and dipole length applied to a high temperature plasma, and seem to be regulated by discrete characteristic relative changes in the magnetic moment, following Syrovatskii's model. Discrete energy pulses are produced when neutral sheet thickness approaches to critical values, proportional to the characteristic relative changes in the magnetic moment. Repetition of pulses may occur in multi-sheet configurations as magnetically complex active centres, or at a single sheet where the total system energy change exceeds the critical conditions. The time-scale of the pulsed energy release may be explained by the tearing mode instability, and the repetition time-scale might be understood by the Sweet mechanism in limit conditions. The mechanism might have attractive applications in other high temperature astrophysical plasmas. An empirical relation is derived for pulses' energy prediction, in orders of magnitude, and some possible tests were suggested. An attempt was made to interpret soft γ-ray events of cosmic origin. (Auth.)

Radiative properties of astrophysical matter: a quest to reproduce astrophysical conditions on earth

International Nuclear Information System (INIS)

Bailey, James E.

2010-01-01

Experiments in terrestrial laboratories can be used to evaluate the physical models that interpret astronomical observations. The properties of matter in astrophysical objects are essential components of these models, but terrestrial laboratories struggle to reproduce the extreme conditions that often exist. Megajoule-class DOE/NNSA facilities such as the National Ignition Facility and Z can create unprecedented amounts of matter at extreme conditions, providing new capabilities to test astrophysical models with high accuracy. Experiments at these large facilities are challenging, and access is very competitive. However, the cylindrically-symmetric Z source emits radiation in all directions, enabling multiple physics experiments to be driven with a single Z discharge. This helps ameliorate access limitations. This article describes research efforts under way at Sandia National Laboratories Z facility investigating radiation transport through stellar interior matter, population kinetics of atoms exposed to the intense radiation emitted by accretion powered objects, and spectral line formation in white dwarf (WD) photospheres. Opacity quantifies the absorption of radiation by matter and strongly influences stellar structure and evolution, since radiation dominates energy transport deep inside stars. Opacity models have become highly sophisticated, but laboratory tests at the conditions existing inside stars have not been possible - until now. Z research is presently focused on measuring iron absorption at conditions relevant to the base of the solar convection zone, where the electron temperature and density are 190 eV and 9 x 10 22 e/cc, respectively. Creating these conditions in a sample that is sufficiently large, long-lived, and uniform is extraordinarily challenging. A source of radiation that streams through the relatively-large samples can produce volumetric heating and thus, uniform conditions, but to achieve high temperatures a strong source is required. Z

MAX: Development of a Laue diffraction lens for nuclear astrophysics

International Nuclear Information System (INIS)

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

2006-01-01

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

Laser fusion and high energy density science

International Nuclear Information System (INIS)

Kodama, Ryosuke

2005-01-01

High-power laser technology is now opening a variety of new fields of science and technology using laser-produced plasmas. The laser plasma is now recognized as one of the important tools for the investigation and application of matter under extreme conditions, which is called high energy density science. This chapter shows a variety of applications of laser-produced plasmas as high energy density science. One of the more attractive industrial and science applications is the generation of intense pulse-radiation sources, such as the generation of electro-magnetic waves in the ranges of EUV (Extreme Ultra Violet) to gamma rays and laser acceleration of charged particles. The laser plasma is used as an energy converter in this regime. The fundamental science applications of high energy density physics are shown by introducing laboratory astrophysics, the equation of state of high pressure matter, including warm dense matter and nuclear science. Other applications are also presented, such as femto-second laser propulsion and light guiding. Finally, a new systematization is proposed to explore the possibility of the high energy density plasma application, which is called high energy plasma photonics''. This is also exploration of the boundary regions between laser technology and beam optics based on plasma physics. (author)

Potentially lethal effects of astrophysical high energy explosive events

International Nuclear Information System (INIS)

Zarauza, Dario; Martin, Osmel; Rolando Cardenas

2007-01-01

In this work we compare the biological extinction risks posed by different types of high energy explosive events, if they occur at distances close enough to inhabited planets. These events are several kinds of supernovae and gamma ray bursts. We mainly consider the ozone depletion, leaving other effects, as photon retransmission and muon showers, for future work. In order to estimate the damage on ozonosphere, we use a simple analytical model for ozone depletion. We also mention some hints to look for the signatures of these events on Earth biogeochemical record, and evaluate the possibility of applying these results to the astrobiologically interesting sample of stars gathered by Porto de Mello, del Peloso and Ghezzi. (Author)

Quark matter in astrophysics and cosmology

International Nuclear Information System (INIS)

Olinto, A.V.

1987-10-01

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

ESA Gaia & the multifrequency behavior of high-energy sources with ultra-low dispersion spectroscopy

Czech Academy of Sciences Publication Activity Database

Hudec, René; Šimon, Vojtěch; Hudec, L.; Hudcová, Věra

2012-01-01

Roč. 83, č. 1 (2012), s. 342-346 ISSN 0037-8720. [Workshop on multifrequency behaviour of high energy cosmic sources. Vulcano, 23.05.2011-28.05.2011] R&D Projects: GA ČR GA205/08/1207 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-rays * high-energy sources * satellites Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy. Stefano Ciroi. Articles written in Journal of Astrophysics and Astronomy. Volume 36 Issue 4 December 2015 pp 447-455 Review. Optical Counterparts of Undetermined Type -Ray Active Galactic Nuclei with Blazar-Like Spectral Energy Distributions.

Criteria for Scaled Laboratory Simulations of Astrophysical MHD Phenomena

International Nuclear Information System (INIS)

Ryutov, D. D.; Drake, R. P.; Remington, B. A.

2000-01-01

We demonstrate that two systems described by the equations of the ideal magnetohydrodynamics (MHD) evolve similarly, if the initial conditions are geometrically similar and certain scaling relations hold. The thermodynamic properties of the gas must be such that the internal energy density is proportional to the pressure. The presence of the shocks is allowed. We discuss the applicability conditions of the ideal MHD and demonstrate that they are satisfied with a large margin both in a number of astrophysical objects, and in properly designed simulation experiments with high-power lasers. This allows one to perform laboratory experiments whose results can be used for quantitative interpretation of various effects of astrophysical MHD. (c) 2000 The American Astronomical Society

Possibilities at LAMPF for studying nuclei of astrophysical interest

International Nuclear Information System (INIS)

Talbert, W.L. Jr.; Bunker, M.E.

1985-01-01

Nuclear data needs in astrophysics range from neutron capture cross sections of a number of stable or near-stable nuclei to decay and neutron binding-energy data for highly neutron-rich nuclei. LAMPF has the potential to contribute significantly to these needs. The new Los Alamos Neutron Scattering Center (LANSCE, aka WNR/PSR) offers world-class capabilities for neutron capture studies up to an MeV or so. The study of nuclei far from stability could be extended into some regions of astrophysical interest using a proposed He-jet coupled mass separator system with a target/production chamber in the LAMPF beam stop area. Specific examples of possible studies at each facility are presented

International Olympiad on Astronomy and Astrophysics

Science.gov (United States)

Soonthornthum, B.; Kunjaya, C.

2011-01-01

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

Physics and astrophysics a selection of key problems

CERN Document Server

Ginzburg, Vitalii Lazarevich

2013-01-01

Physics and Astrophysics discusses some major problems concerned with macrophysics. Such topics as the controlled thermonuclear fusion, high- temperature superconductivity, and metallic exciton liquid in semiconductors are covered. The definition and elements related to microphysics are discussed. This section focuses on mass spectrum, quarks and gluons, and the interaction of particles at high and super high energies. The book gives a brief overview of the general theory of relativity. The production and origin of gravitational waves are discussed in detail. Cosmology is the study of space an

Search for Astrophysical Sources of Neutrinos Using Cascade Events in IceCube

Energy Technology Data Exchange (ETDEWEB)

Aartsen, M. G. [Department of Physics, University of Adelaide, Adelaide, 5005 (Australia); Ackermann, M. [DESY, D-15735 Zeuthen (Germany); Adams, J.; Bagherpour, H. [Dept. of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Aguilar, J. A.; Ansseau, I. [Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Ahlers, M. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Ahrens, M. [Oskar Klein Centre and Dept. of Physics, Stockholm University, SE-10691 Stockholm (Sweden); Al Samarai, I. [Département de physique nucléaire et corpusculaire, Université de Genève, CH-1211 Genève (Switzerland); Altmann, D.; Anton, G. [Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Andeen, K. [Department of Physics, Marquette University, Milwaukee, WI, 53201 (United States); Anderson, T. [Dept. of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Argüelles, C.; Axani, S. [Dept. of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Auffenberg, J. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Bai, X. [Physics Department, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Barwick, S. W. [Dept. of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Baum, V. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany); Collaboration: IceCube Collaboration; and others

2017-09-10

The IceCube neutrino observatory has established the existence of a flux of high-energy astrophysical neutrinos, which is inconsistent with the expectation from atmospheric backgrounds at a significance greater than 5 σ . This flux has been observed in analyses of both track events from muon neutrino interactions and cascade events from interactions of all neutrino flavors. Searches for astrophysical neutrino sources have focused on track events due to the significantly better angular resolution of track reconstructions. To date, no such sources have been confirmed. Here we present the first search for astrophysical neutrino sources using cascades interacting in IceCube with deposited energies as small as 1 TeV. No significant clustering was observed in a selection of 263 cascades collected from 2010 May to 2012 May. We show that compared to the classic approach using tracks, this statistically independent search offers improved sensitivity to sources in the southern sky, especially if the emission is spatially extended or follows a soft energy spectrum. This enhancement is due to the low background from atmospheric neutrinos forming cascade events and the additional veto of atmospheric neutrinos at declinations ≲−30°.

Energy spectrum of tau leptons induced by the high energy Earth-skimming neutrinos

International Nuclear Information System (INIS)

Tseng, J.-J.; Yeh, T.-W.; Lee, F.-F.; Lin, G.-L.; Athar, H.; Huang, M.A.

2003-01-01

We present a semianalytic calculation of the tau-lepton flux emerging from the Earth induced by incident high energy neutrinos interacting inside the Earth for 10 5 ≤E ν /GeV≤10 10 . We obtain results for the energy dependence of the tau-lepton flux coming from the Earth-skimming neutrinos, because of the neutrino-nucleon charged-current scattering as well as the resonant ν(bar sign) e e - scattering. We illustrate our results for several anticipated high energy astrophysical neutrino sources such as the active galactic nuclei, the gamma-ray bursts, and the Greisen-Zatsepin-Kuzmin neutrino fluxes. The tau-lepton fluxes resulting from rock-skimming and ocean-skimming neutrinos are compared. Such comparisons can render useful information about the spectral indices of incident neutrino fluxes

ANTARES: A High Energy Neutrino Undersea Telescope

International Nuclear Information System (INIS)

Hernandez, J.J.

1999-01-01

Neutrinos can reveal a brand new Universe at high energies. The ANTARES collaboration, formed in 1996, works towards the building and deployment of a neutrino telescope. This detector could observe and study high energy astrophysical sources such as X-ray binary systems, young supernova remnants or Active Galactic Nuclei and help to discover or set exclusion limits on some of the elementary particles and objects that have been put forward as candidates to fill the Universe (WIMPS, neutralinos, topological defects, Q-balls, etc.). A neutrino telescope will certainly open a new observational window and can shed light on the most energetic phenomena of the Universe. A review of the progress made by the ANTARES collaboration to achieve this goal is presented. (author)

Studying the high energy cosmic radiation: contributions to its detection and to the exploration of its origin

International Nuclear Information System (INIS)

Lamanna, Giovanni

2009-01-01

The Astro-particle Physics is a discipline where scientists from both the astrophysics and the particle physics communities meets to investigate the Universe aiming to answer to fundamental questions in the field of physics, cosmology and astrophysics. The high energy astrophysics domain, which explores the extremes sources where the larger collective transfer of energy take place, studies the most energetic cosmic radiation as privileged messengers of the history of the Universe. My research path, summarized in this work, is made of personal contributions in the development of new detection technologies, in the data analysis, perspectives and phenomenological studies about the scientific purposes of large experiments: e.g. AMS, ANTARES, HESS, CTA, POLAR. My contributions are the results of research activities in coherence with two main scientific goals in the context of the astro-particle physics domain: - The implication of the high energy cosmic radiation measurement for the investigation on the nature and distribution of the dark matter; - The investigation of the origin of the galactic cosmic radiation for the understanding of the most energetic processes in the Universe. (author)

Nuclear astrophysics: An application of nuclear physics

International Nuclear Information System (INIS)

Fueloep, Z.

2005-01-01

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

Recent results in nuclear astrophysics

Energy Technology Data Exchange (ETDEWEB)

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

2015-03-01

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

Recent results in nuclear astrophysics

International Nuclear Information System (INIS)

Coc, Alain; Kiener, Juergen; Hammache, Fairouz

2015-01-01

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

Dynamics and evolution of galactic nuclei (princeton series in astrophysics)

CERN Document Server

Merritt, David

2013-01-01

Deep within galaxies like the Milky Way, astronomers have found a fascinating legacy of Einstein's general theory of relativity: supermassive black holes. Connected to the evolution of the galaxies that contain these black holes, galactic nuclei are the sites of uniquely energetic events, including quasars, stellar tidal disruptions, and the generation of gravitational waves. This textbook is the first comprehensive introduction to dynamical processes occurring in the vicinity of supermassive black holes in their galactic environment. Filling a critical gap, it is an authoritative resource for astrophysics and physics graduate students, and researchers focusing on galactic nuclei, the astrophysics of massive black holes, galactic dynamics, and gravitational wave detection. It is an ideal text for an advanced graduate-level course on galactic nuclei and as supplementary reading in graduate-level courses on high-energy astrophysics and galactic dynamics. David Merritt summarizes the theoretical work of the las...

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

International Nuclear Information System (INIS)

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

Results of search for the point superhigh-energy gamma ray sources carried out in the Crimean Astrophysical Observatory in the years 1969-1973

International Nuclear Information System (INIS)

Stepanyan, A.A.; Vladimirskij, B.M.; Neshpor, Yu.I.; Fomin, V.P.

1975-01-01

Astrophysical objects possessing high density of ultrahigh energy γ-particles are observed. The observations have been carried out in the Crimean astrophysical observatory of the AN SSSR for the period of 1969-1973. 43 celestial objects have been chosen for observation, among them are both the supposed and well-known sources of hard electromaanetic radiation (x-ray or γ-radiation with the energy of quanta up to 10 -8 eV). Regular observations of celestial bodies are followed by recording Cherenkov bursts by method of scanning with two groups of detectors, each consisting of two parallel-directed light detectors switched on to coincidences. Criteria for selecting the material are described. Paricular attention is paid to stability of the equipment parameters, permanent atmospheric transparency, presence of such atmospheric phenomena as meteors, summer lightings, and so on. As the objects under observation the authors involve x-ray sources, pulsars, supernovae, novae, supernovae remnants, radiogalaxies, point γ-sources. The data obtained and also those of other authors are summarized in a catalog including 72 objects from the Northern part of the celestial sphere

The fluorine destruction in stars: First experimental study of the 19F(p,α)16O reaction at astrophysical energies

International Nuclear Information System (INIS)

La Cognata, M.; Mukhamedzhanov, A.; Spitaleri, C.; Indelicato, I.; Aliotta, M.; Burjan, V.; Cherubini, S.; Coc, A.; Gulino, M.; Hons, Z.; Kiss, G. G.; Kroha, V.; Lamia, L.; Mrazek, J.; Palmerini, S.; Piskor, S.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.

2012-01-01

The 19 F(p,α) 16 O reaction is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars and it might also play a role in hydrogendeficient post-AGB star nucleosynthesis. So far, available direct measurements do not reach the energy region of astrophysical interest (E cm ∼ 300 keV), because of the hindrance effect of the Coulomb barrier. The Trojan Horse (TH) method was thus used to access this energy region, by extracting the quasi-free contribution to the 2 H( 19 F,α 16 O)n reaction. The TH measurement of the α 0 channel, which is the dominant one at such energies, shows the presence of resonant structures not observed before that cause an increase of the reaction rate at astrophysical temperatures up to a factor of 1.7, with potential important consequences for stellar nucleosynthesis.

Recent Progresses in Ab-Initio Studies of Low-Energy Few-Nucleon Reactions of Astrophysical Interest

Science.gov (United States)

Marcucci, Laura E.

2017-03-01

We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis. Related to this, we will discuss also the most recent calculation of tritium β -decay. Two frameworks will be considered, the conventional and the chiral effective field theory approach.

The Multi-Messenger Approach to High-Energy Gamma-Ray Sources

CERN Document Server

Paredes, Josep M; Torres, Diego F

2008-01-01

This book provides a theoretical and observational overview of the state of the art of gamma-ray astrophysics, and their impact and connection with the physics of cosmic rays and neutrinos. With the aim of shedding new and fresh light on the problem of the nature of the gamma-ray sources, particularly those yet unidentified, this book summarizes contributions to a workshop that continues with the series initiated by the meeting held at Tonantzintla in October 2000, and Hong-Kong in May 2004. This books will be of interest for all active researchers in the field of high energy astrophysics and astroparticle physics, as well as for graduate students entering into the subject.

Astrophysical Flows

Science.gov (United States)

Pringle, James E.; King, Andrew

2003-07-01

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

Exploring extreme plasma physics in the laboratory and in astrophysics

Science.gov (United States)

Silva, L. O.; Grismayer, T.; Fonseca, R. A.; Cruz, F.; Gaudio, F. D.; Martins, J. L.; Vieira, J.; Vranic, M.

2017-10-01

The interaction of ultra intense fields with plasmas is at the confluence of several sub-fields ranging from QED, and nuclear physics to high energy astrophysics, and fundamental plasma processes. It requires novel theoretical tools, highly optimised numerical codes and algorithms tailored to these complex scenarios, where physical mechanisms at very disparate temporal and spatial scales are self-consistently coupled in multidimensional geometries. The key developments implemented in Osiris will be presented along with some examples of problems, relevant for laboratory or astrophysical scenarios, that are being addressed resorting to the combination of massively parallel simulations with theoretical models. The relevance for near future experimental facilities such as ELI will also be presented. Work supported by the European Research Council (ERC-AdG-2015 InPairs Grant No. 695088).

An Experimental and Theoretical High Energy Physics Program

Energy Technology Data Exchange (ETDEWEB)

Shipsey, Ian

2012-07-31

The Purdue High Energy Physics Group conducts research in experimental and theoretical elementary particle physics and experimental high energy astrophysics. Our goals, which we share with high energy physics colleagues around the world, are to understand at the most fundamental level the nature of matter, energy, space and time, and in order to explain the birth, evolution and fate of the Universe. The experiments in which we are currently involved are: CDF, CLEO-c, CMS, LSST, and VERITAS. We have been instrumental in establishing two major in-house facilities: The Purdue Particle Physics Microstructure Detector Facility (P3MD) in 1995 and the CMS Tier-2 center in 2005. The research efforts of the theory group span phenomenological and theoretical aspects of the Standard Model as well as many of its possible extensions. Recent work includes phenomenological consequences of supersymmetric models, string theory and applications of gauge/gravity duality, the cosmological implications of massive gravitons, and the physics of extra dimensions.

Nuclear Astrophysics from View Point of Few-Body Problems

International Nuclear Information System (INIS)

Tumino, A.; Spitaleri, C.; Bertulani, C.; Mukhamedzhanov, A.M.

2013-01-01

Few-body systems provide very useful tools to solve different problems for nuclear astrophysics. This is the case of indirect techniques, developed to overcome some of the limits of direct measurements at astrophysical energies. Here the Coulomb dissociation, the asymptotic normalization coefficient and the Trojan Horse method are discussed. (author)

Search for a diffuse flux of astrophysical muon neutrinos with the IceCube 40-string detector

International Nuclear Information System (INIS)

Abbasi, R.; Aguilar, J. A.; Andeen, K.; Baker, M.; BenZvi, S.; Chirkin, D.; Desiati, P.; Diaz-Velez, J. C.; Dumm, J. P.; Eisch, J.; Feintzeig, J.; Gladstone, L.; Grullon, S.; Halzen, F.; Hill, G. C.; Hoshina, K.; Jacobsen, J.; Karle, A.; Krasberg, M.; Kurahashi, N.

2011-01-01

The IceCube Neutrino Observatory is a 1 km 3 detector currently taking data at the South Pole. One of the main strategies used to look for astrophysical neutrinos with IceCube is the search for a diffuse flux of high-energy neutrinos from unresolved sources. A hard energy spectrum of neutrinos from isotropically distributed astrophysical sources could manifest itself as a detectable signal that may be differentiated from the atmospheric neutrino background by spectral measurement. This analysis uses data from the IceCube detector collected in its half completed configuration which operated between April 2008 and May 2009 to search for a diffuse flux of astrophysical muon neutrinos. A total of 12 877 upward-going candidate neutrino events have been selected for this analysis. No evidence for a diffuse flux of astrophysical muon neutrinos was found in the data set leading to a 90% C.L. upper limit on the normalization of an E -2 astrophysical ν μ flux of 8.9x10 -9 GeV cm -2 s -1 sr -1 . The analysis is sensitive in the energy range between 35 TeV and 7 PeV. The 12 877 candidate neutrino events are consistent with atmospheric muon neutrinos measured from 332 GeV to 84 TeV and no evidence for a prompt component to the atmospheric neutrino spectrum is found.

Cosmological birefringence constraints from CMB and astrophysical polarization data

Energy Technology Data Exchange (ETDEWEB)

Galaverni, M. [Studio Teologico Interdiocesano, V.le Timavo 93, Reggio Emilia, 42121 Italy (Italy); Gubitosi, G. [Dipartimento di Fisica and sez. Roma1 INFN, Università di Roma ' La Sapienza' , P.le A. Moro 2, Rome, 00185 Italy (Italy); Paci, F. [SISSA, Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, Trieste, 34136 Italy (Italy); Finelli, F., E-mail: matteo.galaverni@gmail.com, E-mail: giulia.gubitosi@imperial.ac.uk, E-mail: fpaci@sissa.it, E-mail: finelli@iasfbo.inaf.it [INAF-IASF Bologna, via Gobetti 101, Bologna, I-40129 Italy (Italy)

2015-08-01

Cosmological birefringence is a rotation of the polarization plane of photons coming from sources of astrophysical and cosmological origin. The rotation can also depend on the energy of the photons and not only on the distance of the source and on the cosmological evolution of the underlying theoretical model. In this work, we constrain few selected models for cosmological birefringence, combining CMB and astrophysical data at radio, optical, X and γ wavelengths, taking into account the specific energy and distance dependences.

22nd DAE High Energy Physics Symposium

CERN Document Server

2018-01-01

These proceedings gather invited and contributed talks presented at the XXII DAE-BRNS High Energy Physics (HEP) Symposium, which was held at the University of Delhi, India, on 12–16 December 2016. The contributions cover a variety of topics in particle physics, astroparticle physics, cosmology and related areas from both experimental and theoretical perspectives, namely (1) Neutrino Physics, (2) Standard Model Physics (including Electroweak, Flavour Physics), (3) Beyond Standard Model Physics, (4) Heavy Ion Physics & QCD (Quantum Chromodynamics), (5) Particle Astrophysics & Cosmology, (6) Future Experiments and Detector Development, (7) Formal Theory, and (8) Societal Applications: Medical Physics, Imaging, etc. The DAE-BRNS High Energy Physics Symposium, widely considered to be one of the leading symposiums in the field of Elementary Particle Physics, is held every other year in India and supported by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE), India. As man...

Astrophysical observations: lensing and eclipsing Einstein's theories.

Science.gov (United States)

Bennett, Charles L

2005-02-11

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

QCD and high-energy nuclear collisions

CERN Multimedia

CERN. Geneva

2007-01-01

Six years ago, Relativistic Heavy Ion Collider at Brookhaven started colliding heavy nuclei at record center-of-mass energies of up to 200 GeV/nucleon. Very soon, the Large Hadron Collider at CERN will push the energy of the ions to an astounding 5 TeV/nucleon. What can be learnt from the experiments at these machines? What do we know about the physics of super--dense matter already? I will argue that heavy ion accelerators bring us to the new frontiers of physical knowledge by creating strong color fields and very high densities of partons, at which qualitatively new phenomena emerge. I will also discuss the cross-disciplinary implications for cosmology, astrophysics, and connections to condensed matter physics.

Investigation of high-energy sources in optical light by ESA Gaia

Czech Academy of Sciences Publication Activity Database

Hudec, R.; Šimon, Vojtěch; Hudec, L.; Hudcová, Věra

2010-01-01

Roč. 81, č. 1 (2010), s. 476-481 ISSN 0037-8720. [Multifrequency behaviour of high energy cosmic sources. Vulcano, 25.05.2009-30.05. 2009] R&D Projects: GA ČR GA205/08/1207 Grant - others:ESA(XE) ESA- PECS project No. 98058; GA ČR(CZ) GA102/09/0997; GA MŠk(CZ) ME09027; ESA(XE) ESA- PECS project No. 98023 Institutional research plan: CEZ:AV0Z10030501 Keywords : high-energy sources * cataclysmic variables * low-dispersion spectra Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Astrophysics and the exploration of the universe

International Nuclear Information System (INIS)

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

2009-01-01

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

Astrophysics a very short introduction

CERN Document Server

Binney, James

2016-01-01

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

Dark energy and equivalence principle constraints from astrophysical tests of the stability of the fine-structure constant

Energy Technology Data Exchange (ETDEWEB)

Martins, C.J.A.P.; Pinho, A.M.M.; Alves, R.F.C. [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Pino, M. [Institut Domènech i Montaner, C/Maspujols 21-23, 43206 Reus (Spain); Rocha, C.I.S.A. [Externato Ribadouro, Rua de Santa Catarina 1346, 4000-447 Porto (Portugal); Wietersheim, M. von, E-mail: Carlos.Martins@astro.up.pt, E-mail: Ana.Pinho@astro.up.pt, E-mail: up201106579@fc.up.pt, E-mail: mpc_97@yahoo.com, E-mail: cisar97@hotmail.com, E-mail: maxivonw@gmail.com [Institut Manuel Sales i Ferré, Avinguda de les Escoles 6, 43550 Ulldecona (Spain)

2015-08-01

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant α, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic clock tests and Type Ia supernova and Hubble parameter data, constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling, ζ, to the electromagnetic sector) the α variation. Specifically, current data tightly constrains a combination of ζ and the present dark energy equation of state w{sub 0}. Moreover, in these models the new degree of freedom inevitably couples to nucleons (through the α dependence of their masses) and leads to violations of the Weak Equivalence Principle. We obtain indirect bounds on the Eötvös parameter η that are typically stronger than the current direct ones. We discuss the model-dependence of our results and briefly comment on how the forthcoming generation of high-resolution ultra-stable spectrographs will enable significantly tighter constraints.

Dark energy and equivalence principle constraints from astrophysical tests of the stability of the fine-structure constant

International Nuclear Information System (INIS)

Martins, C.J.A.P.; Pinho, A.M.M.; Alves, R.F.C.; Pino, M.; Rocha, C.I.S.A.; Wietersheim, M. von

2015-01-01

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant α, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic clock tests and Type Ia supernova and Hubble parameter data, constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling, ζ, to the electromagnetic sector) the α variation. Specifically, current data tightly constrains a combination of ζ and the present dark energy equation of state w 0 . Moreover, in these models the new degree of freedom inevitably couples to nucleons (through the α dependence of their masses) and leads to violations of the Weak Equivalence Principle. We obtain indirect bounds on the Eötvös parameter η that are typically stronger than the current direct ones. We discuss the model-dependence of our results and briefly comment on how the forthcoming generation of high-resolution ultra-stable spectrographs will enable significantly tighter constraints

UNIVERSITY OF ARIZONA HIGH ENERGY PHYSICS PROGRAM

Energy Technology Data Exchange (ETDEWEB)

Rutherfoord, John P. [University of Arizona; Johns, Kenneth A. [University of Arizona; Shupe, Michael A. [University of Arizona; Cheu, Elliott C. [University of Arizona; Varnes, Erich W. [University of Arizona; Dienes, Keith [University of Arizona; Su, Shufang [University of Arizona; Toussaint, William Doug [University of Arizona; Sarcevic, Ina [University of Arizona

2013-07-29

The High Energy Physics Group at the University of Arizona has conducted forefront research in elementary particle physics. Our theorists have developed new ideas in lattice QCD, SUSY phenomenology, string theory phenomenology, extra spatial dimensions, dark matter, and neutrino astrophysics. The experimentalists produced significant physics results on the ATLAS experiment at CERN's Large Hadron Collider and on the D0 experiment at the Fermilab Tevatron. In addition, the experimentalists were leaders in detector development and construction, and on service roles in these experiments.

Research in nuclear astrophysics

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1989-01-01

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

Laboratory studies of photoionized plasma related to astrophysics

International Nuclear Information System (INIS)

Yang Peiqiang; Wang Feilu; Zhao Gang

2011-01-01

Photoionized plasma is universal in astronomy and has great importance on account of its close relation to compact astrophysical objects such as black holes. Recently, with the development of high energy density lasers and Z-pinch facilities, it has become possible to simulate astronomical photoionized plasma in the laboratory. These experiments help us to benchmark and modify the photoionization models, and to understand the photoionization processes to diagnose related astronomical plasma environments. (authors)

TPCs in high-energy astronomical polarimetry

International Nuclear Information System (INIS)

Black, J K

2007-01-01

High-energy astrophysics has yet to exploit the unique and important information that polarimetry could provide, largely due to the limited sensitivity of previously available polarimeters. In recent years, numerous efforts have been initiated to develop instruments with the sensitivity required for astronomical polarimetry over the 100 eV to 10 GeV band. Time projection chambers (TPCs), with their high-resolution event imaging capability, are an integral part of some of these efforts. After a brief overview of current astronomical polarimeter development efforts, the role of TPCs will be described in more detail. These include TPCs as photoelectric X-ray polarimeters and TPCs as components of polarizationsensitive Compton and pair-production telescopes

Alpha resonant scattering for astrophysical reaction studies

International Nuclear Information System (INIS)

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

2014-01-01

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

An introduction to nuclear astrophysics

International Nuclear Information System (INIS)

Norman, E.B.

1987-09-01

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

Laboratory astrophysics. Model experiments of astrophysics with large-scale lasers

International Nuclear Information System (INIS)

Takabe, Hideaki

2012-01-01

I would like to review the model experiment of astrophysics with high-power, large-scale lasers constructed mainly for laser nuclear fusion research. The four research directions of this new field named 'Laser Astrophysics' are described with four examples mainly promoted in our institute. The description is of magazine style so as to be easily understood by non-specialists. A new theory and its model experiment on the collisionless shock and particle acceleration observed in supernova remnants (SNRs) are explained in detail and its result and coming research direction are clarified. In addition, the vacuum breakdown experiment to be realized with the near future ultra-intense laser is also introduced. (author)

Final Technical Report: Magnetic Reconnection in High-Energy Laser-Produced Plasmas

Energy Technology Data Exchange (ETDEWEB)

Germaschewski, Kai [Univ. of New Hampshire, Durham, NH (United States); Fox, William [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bhattacharjee, Amitava [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2017-04-06

This report describes the final results from the DOE Grant DE-SC0007168, “Fast Magnetic Reconnection in HED Laser-Produced Plasmas.” The recent generation of laboratory high-energy-density physics facilities has opened significant physics opportunities for experimentally modeling astrophysical plasmas. The goal of this proposal is to use these new tools to study fundamental problems in plasma physics and plasma astrophysics. Fundamental topics in this area involve study of the generation, amplification, and fate of magnetic fields, which are observed to pervade the plasma universe and govern its evolution. This project combined experiments at DOE laser facilities with kinetic plasma simulation to study these processes. The primary original goal of the project was to study magnetic reconnection using a new experimental platform, colliding magnetized laser-produced plasmas. However through a series of fortuitous discoveries, the work broadened out to allow significant advancement on multiple topics in laboratory astrophysics, including magnetic reconnection, Weibel instability, and collisionless shocks.

Science on high-energy lasers: From today to the NIF

International Nuclear Information System (INIS)

Lee, R.W.; Petrasso, R.; Falcone, R.W.

1995-01-01

This document presents both a concise definition of the current capabilities of high energy lasers and a description of capabilities of the NIF (National Ignition Facility). Five scientific areas are discussed (Astrophysics, Hydrodynamics, Material Properties, Plasma Physics, Radiation Sources, and Radiative Properties). In these five areas we project a picture of the future based on investigations that are being carried on today. Even with this very conservative approach we find that the development of new higher energy lasers will make many extremely exciting areas accessible to us

Advanced Telescope for High Energy Nuclear Astrophysics (ATHENA)

National Research Council Canada - National Science Library

Johnson, W. N; Dermer, C; Kroeger, R. A; Kurfess, J. D; Gehrels, N; Grindlay, J; Leising, M. D; Prince, T; Purcell, W; Ryan, J; Tumer, T

1995-01-01

We present a space mission concept for a low energy gamma-ray telescope, ATHENA, which is under investigation as the next major advance in gamma-ray spectroscopy following the current COMPTON Gamma...

High energy-density science on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Campbell, E.M.; Cauble, R.; Remington, B.A.

1997-08-01

The National Ignition Facility, as well as its French counterpart Le Laser Megajoule, have been designed to confront one of the most difficult and compelling problem in shock physics - the creation of a hot, compassed DT plasma surrounded and confined by cold, nearly degenerate DT fuel. At the same time, these laser facilities will present the shock physics community with unique tools for the study of high energy density matter at states unreachable by any other laboratory technique. Here we describe how these lasers can contribute to investigations of high energy density in the area of material properties and equations of state, extend present laboratory shock techniques such as high-speed jets to new regimes, and allow study of extreme conditions found in astrophysical phenomena.

The future of high energy gamma ray astronomy and its potential astrophysical implications

Science.gov (United States)

Fichtel, C. E.

1982-01-01

Future satellites should carry instruments having over an order of magnitude greater sensitivity than those flown thus far as well as improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance knowledge of: the very energetic and nuclear processes associated with compact objects; the structure of our galaxy; the origin and dynamic pressure effects of the cosmic rays; the high energy particles and energetic processes in other galaxies; and the degree of matter-antimatter symmetry of the universe. The relevant aspects of extragalactic gamma ray phenomena are emphasized along with the instruments planned. The high energy gamma ray results of forthcoming programs such as GAMMA-1 and the Gamma Ray Observatory should justify even more sophisticated telescopes. These advanced instruments might be placed on the space station currently being considered by NASA.

γ astrophysics above 10-30 GeV with the MAGIC telescope

International Nuclear Information System (INIS)

Mirzoyan, Razmick

1999-01-01

The project on the 17 m oe telescope, dubbed MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescope), is dedicated for γ astrophysics in the energy range from 10-30 GeV till 50-100 TeV. MAGIC will for the first time allow to explore with very high sensitivity the energy range 10-300 GeV and to bridge the existing energy gap between satellite and ground-based air Cherenkov measurements. We believe MAGIC will serve as a prototype for future multi-telescope γ ray observatories

FIRST KODAI-TRIESTE WORKSHOP ON PLASMA ASTROPHYSICS

CERN Document Server

Hasan, S. S; Krishan, V; TURBULENCE, DYNAMOS, ACCRETION DISKS, PULSARS AND COLLECTIVE PLASMA PROCESSES

2008-01-01

It is well established and appreciated by now that more than 99% of the baryonic matter in the universe is in the plasma state. Most astrophysical systems could be approximated as conducting fluids in a gravitational field. It is the combined effect of these two that gives rise to the mind boggling variety of configurations in the form of filaments, loops , jets and arches. The plasma structures that cannot last for more than a second or less in a laboratory remain intact for astronomical time and spatial scales in an astrophysical setting. The case in point is the well known extragalactic jets whose collimation and stability has remained an enigma inspite of the efforts of many for many long years. The high energy radiation sources such as the active galactic nuclei again summon the coherent plasma radiation processes for their exceptionally large output from regions of relatively small physical sizes. The generation of magnetic field, anomalous transport of angular momentum with decisive bearing on star for...

Fundamental Questions in Astrophysics: Guidelines for Future UV Observatories

CERN Document Server

Gómez de Castro, Ana I

2006-01-01

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

First evidences for 19F(α, p)22Ne at astrophysical energies

International Nuclear Information System (INIS)

D’Agata, G.; Spitaleri, C.; Pizzone, R.G.; Figuera, P.; Guardo, G.L.; Gulino, M.; Indelicato, I.; La Cognata, M.; Lattuada, M.; Sergi, M.L.; Blagus, S.; Mijatović, T.; Milin, M.; Miljanic, D.; Prepolec, L.; Skukan, N.; Grassi, L.; Lamia, L.; Hayakawa, S.; Kshetri, R.

2016-01-01

19 F experimental abundances is overestimated in respect to the theoretical one: it is therefore clear that further investigations are needed. We focused on the 19 F(α, p) 22 Ne reaction, representing the main destruction channel in He-rich environments. The lowest energy at which this reaction has been studied with direct methods is E C.M. ≈ 0.91 MeV, while the Gamow region is between 0.39 ÷ 0.8 MeV, far below the Coulomb barrier (3.8 MeV). For this reason, an experiment at Rudjer Boskovic Institute (Zagreb) was performed, applying the Trojan Horse Method. Following this method we selected the quasi-free contribution coming from 6 Li( 19 F,p 22 Ne) 2 H at E beam =6 MeV at kinematically favourable angles, and the cross section at energies 0 < E C.M. < 1.4 MeV was extracted in arbitrary units, covering the astrophysical region of interest. (paper)

Search for point-like sources using the diffuse astrophysical muon-neutrino flux in IceCube

Energy Technology Data Exchange (ETDEWEB)

Reimann, Rene; Haack, Christian; Raedel, Leif; Schoenen, Sebastian; Schumacher, Lisa; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen (Germany); Collaboration: IceCube-Collaboration

2016-07-01

IceCube, a cubic-kilometer sized neutrino detector at the geographic South Pole, has recently confirmed a flux of high-energy astrophysical neutrinos in the track-like muon channel. Although this muon-neutrino flux has now been observed with high significance, no point sources or source classes could be identified yet with these well pointing events. We present a search for point-like sources based on a six year sample of upgoing muon-neutrinos with very low background contamination. To improve the sensitivity, the standard likelihood approach has been modified to focus on the properties of the measured astrophysical muon-neutrino flux.

Experimental physics 4. Nuclear, particle and astrophysics. 5. ed.; Experimentalphysik 4. Kern-, Teilchen- und Astrophysik

Energy Technology Data Exchange (ETDEWEB)

Demtroeder, Wolfgang

2017-09-01

The following topics are dealt with: Structure of atomic nuclei, unstable nuclei and radioactivity, experimental techniques in nuclear and high-energy physics, nuclear forces and nuclear models, nuclear reactions, physics of elementary particles, applications of nuclear and high-energy physics, foundations of experimental astronomy and astrophysics, our solar system, birth, life, and death of stars, the development and present structure of the universe. (HSI)

Very high energy gamma ray astrophysics

International Nuclear Information System (INIS)

Lamb, R.C.; Lewis, D.A.

1990-02-01

Our scientific goal is to discover and study by means of gamma-ray astronomy those regions of the universe where particles are accelerated to extreme energies. The atmospheric Cherenkov technique provides a unique and potentially sensitive window in the region of 10 11 to approximately 10 14 eV for this purpose. The Whipple Observatory Collaboration is currently engaged in the development of a Cherenkov camera which has the ultimate capability of distinguishing gamma-ray showers from the numerous cosmic-ray background showers by imaging the Cherenkov light from each shower. We have recently demonstrated the potential of the imaging technique with our 18 sigma detection of TeV photons from the Crab Nebula using a camera of 10 elements, pixel spacing 0.25 degrees. This detection represents a factor of 10 improvement in sensitivity compared to a non-imaging detector. The next step in the development of the detector is to obtain a second large reflector, similar to the present 10 meter instrument, for stereoscopic viewing of showers. This project, named GRANITE, is now approved by DOE. With GRANITE it should be possible to probe more deeply in space by a factor of 7, and to fully investigate the possibility of new physics which has been suggested by reports of anomalous radiation from Hercules X-1. 18 refs

Essential astrophysics

CERN Document Server

Lang, Kenneth R

2013-01-01

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

High-Energy Astrophysics with the High Altitude Water Cherenkov (HAWC) Observatory

Science.gov (United States)

Pretz, John; HAWC Collaboration

2013-04-01

The High Altitude Water Cherenkov (HAWC) observatory, under construction at Sierra Negra in the state of Puebla, Mexico, consists of a 22500 square meter area of water Cherenkov detectors: water tanks instrumented with light-sensitive photomultiplier tubes. The experiment is used to detect energetic secondary particles reaching the ground when a 50 GeV to 100 TeV cosmic ray or gamma ray interacts in the atmosphere above the experiment. By timing the arrival of particles on the ground, the direction of the original primary particle may be resolved with an error of between 1.0 (50 GeV) and 0.1 (10 TeV) degrees. Gamma-ray primaries may be distinguished from cosmic ray background by identifying the penetrating particles characteristic of a hadronic particle shower. The instrument is 10% complete and is performing as expected, with 30% of the channels anticipated by the summer of 2013. HAWC will complement existing Imaging Atmospheric Cherenkov Telescopes and space-based gamma-ray telescopes with its extreme high-energy sensitivity and its large field-of-view. The observatory will be used to study particle acceleration in Pulsar Wind Nebulae, Supernova Remnants, Active Galactic Nuclei and Gamma-ray Bursts. Additionally, the instrument can be used to probe dark matter annihilation in halo and sub-halos of the galaxy. We will present the sensitivity of the HAWC instrument in the context of the main science objectives. We will also present the status of the deployment including first data from the instrument and prospects for the future.

Ultra high energy gamma rays and observations with CYGNUS/MILAGRO

International Nuclear Information System (INIS)

Weeks, D.D.; Yodh, G.B.

1992-01-01

This talk discusses high-energy observations of the Crab pulsar/nebula and the pulsar in the X-ray binary, Hercules X-1, and makes the case for continued observations with ground-based γ-ray detectors. The CYGNUS Air Shower Array has a wide field of view on monitors several astrophysical γ-ray sources at the same time, many of which are prime objects observed by the Compton Gamma Ray Observatory (GRO) and air Cerenkov telescopes. This array and the future MILAGRO Water Cerenkov Detector can perform observations that are simultaneous with similar experiments to provide confirmation of emission, and can measure source spectra at a range of high energies previously unexplored

Laboratory Astrophysics Prize: Laboratory Astrophysics with Nuclei

Science.gov (United States)

Wiescher, Michael

2018-06-01

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

Nuclear astrophysics: Recent results on CNO-cycle reactions and AGB nucleosynthesis

International Nuclear Information System (INIS)

La Cognata, M.

2011-01-01

Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 100 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method and new experimental facilities such as deep underground laboratories have been devised yielding new cutting-edge results.

Studies in nuclear structure relevant to Astrophysics: theoretical and experimental efforts

International Nuclear Information System (INIS)

Saha Sarkar, Maitreyee

2016-01-01

Experimental and theoretical investigations in the region around doubly magic neutron rich 132 Sn nucleus have recently revealed many intriguing issues concerning some newer aspects of nuclear structure in such exotic environments. These nuclei lie on or close to the path of the astrophysical r-process flow. A glimpse of the implication of these studies on the r-process nucleosynthesis will be discussed. Presently, the Nuclear Physics group in Saha Institute of Nuclear Physics is working for installation of a high-current, low energy Accelerator as the primary component of the Facility for Research in low Energy Nuclear Astrophysics (FRENA), a national facility, at Kolkata. Planning for future experiments has been undertaken for successful utilization of this facility. Implantation technique has been found to be one of the most effective methods to produce isotopically pure targets. We have prepared a few isotopically pure targets using this technique. Being the slowest process of the CNO cycle, study of the 14 N(p, γ) 15 O(Q = 7297 keV) capture reaction is of high astrophysical interest. From an experiment utilizing one of the newly prepared 14 N implanted targets, a preliminary estimate of the lifetime of 6792 keV state in 15 O has been obtained, using Doppler shift attenuation method (DSAM). The sensitivity of the results with respect to the uncertainties in various input quantities has been tested. This endeavour will be helpful to design a better experiment to extract more precise lifetime for this important state

High energy neutrinos from astrophysical accelerators of cosmic ray nuclei

Science.gov (United States)

Anchordoqui, Luis A.; Hooper, Dan; Sarkar, Subir; Taylor, Andrew M.

2008-02-01

Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or photons. However, there will be a reduction in the predicted neutrino flux if cosmic ray sources accelerate not only protons but also significant numbers of heavier nuclei, as is indicated by recent air shower data. We consider plausible extragalactic sources such as active galactic nuclei, gamma ray bursts and starburst galaxies and demand consistency with the observed cosmic ray composition and energy spectrum at Earth after allowing for propagation through intergalactic radiation fields. This allows us to calculate the expected neutrino fluxes from the sources, normalized to the observed cosmic ray spectrum. We find that the likely signals are still within reach of next generation neutrino telescopes such as IceCube.PACS95.85.Ry98.70.Rz98.54.Cm98.54.EpReferencesFor a review, see:F.HalzenD.HooperRep. Prog. Phys.6520021025A.AchterbergIceCube CollaborationPhys. Rev. Lett.972006221101A.AchterbergIceCube CollaborationAstropart. Phys.262006282arXiv:astro-ph/0611063arXiv:astro-ph/0702265V.NiessANTARES CollaborationAIP Conf. Proc.8672006217I.KravchenkoPhys. Rev. D732006082002S.W.BarwickANITA CollaborationPhys. Rev. Lett.962006171101V.Van ElewyckPierre Auger CollaborationAIP Conf. Proc.8092006187For a survey of possible sources and event rates in km3 detectors see e.g.,W.BednarekG.F.BurgioT.MontaruliNew Astron. Rev.4920051M.D.KistlerJ.F.BeacomPhys. Rev. D742006063007A. Kappes, J. Hinton, C. Stegmann, F.A. Aharonian, arXiv:astro-ph/0607286.A.LevinsonE.WaxmanPhys. Rev. Lett.872001171101C.DistefanoD.GuettaE.WaxmanA.LevinsonAstrophys. J.5752002378F.A.AharonianL.A.AnchordoquiD.KhangulyanT.MontaruliJ. Phys. Conf. Ser.392006408J.Alvarez-MunizF.HalzenAstrophys. J.5762002L33F.VissaniAstropart. Phys.262006310F

Astrophysics days and MHD

International Nuclear Information System (INIS)

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

2001-05-01

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

Alpha resonant scattering for astrophysical reaction studies

Energy Technology Data Exchange (ETDEWEB)

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

2014-05-02

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

HIGH-ENERGY COSMIC-RAY DIFFUSION IN MOLECULAR CLOUDS: A NUMERICAL APPROACH

International Nuclear Information System (INIS)

Fatuzzo, M.; Melia, F.; Todd, E.; Adams, F. C.

2010-01-01

The propagation of high-energy cosmic rays (CRs) through giant molecular clouds constitutes a fundamental process in astronomy and astrophysics. The diffusion of CRs through these magnetically turbulent environments is often studied through the use of energy-dependent diffusion coefficients, although these are not always well motivated theoretically. Now, however, it is feasible to perform detailed numerical simulations of the diffusion process computationally. While the general problem depends upon both the field structure and particle energy, the analysis may be greatly simplified by dimensionless analysis. That is, for a specified purely turbulent field, the analysis depends almost exclusively on a single parameter-the ratio of the maximum wavelength of the turbulent field cells to the particle gyration radius. For turbulent magnetic fluctuations superimposed over an underlying uniform magnetic field, particle diffusion depends on a second dimensionless parameter that characterizes the ratio of the turbulent to uniform magnetic field energy densities. We consider both of these possibilities and parametrize our results to provide simple quantitative expressions that suitably characterize the diffusion process within molecular cloud environments. Doing so, we find that the simple scaling laws often invoked by the high-energy astrophysics community to model CR diffusion through such regions appear to be fairly robust for the case of a uniform magnetic field with a strong turbulent component, but are only valid up to ∼50 TeV particle energies for a purely turbulent field. These results have important consequences for the analysis of CR processes based on TeV emission spectra associated with dense molecular clouds.

Indirect techniques in nuclear astrophysics. Asymptotic normalization coefficient and trojan horse

International Nuclear Information System (INIS)

Mukhamedzhanov, A.M.; Gagliardi, C.A.; Pirlepesov, F.; Trache, L.; Tribble, R.E.; Blokhintsev, L.D.; Brown, B.A.; Nunes, F.M.; Burjan, V.; Kroha, V.; Cherubini, S.; Pizzone, R.G.; Romano, S.; Spitaleri, C.; Tumino, A.; Irgaziev, B.F.; Tang, X.D.

2006-01-01

Owing to the presence of the Coulomb barrier at astrophysically relevant kinetic energies it is very difficult, or sometimes impossible, to measure astrophysical reaction rates in the laboratory. That is why different indirect techniques are being used along with direct measurements. Here we address two important indirect techniques, the asymptotic normalization coefficient (ANC) and the Trojan Horse (TH) methods. We discuss the application of the ANC technique for calculation of the astrophysical processes in the presence of subthreshold bound states, in particular, two different mechanisms are discussed: direct capture to the subthreshold state and capture to the low-lying bound states through the subthreshold state, which plays the role of the subthreshold resonance. The ANC technique can also be used to determine the interference sign of the resonant and nonresonant (direct) terms of the reaction amplitude. The TH method is unique indirect technique allowing one to measure astrophysical rearrangement reactions down to astrophysically relevant energies. We explain why there is no Coulomb barrier in the sub-process amplitudes extracted from the TH reaction. The expressions for the TH amplitude for direct and resonant cases are presented. (orig.)

β-delayed α decay of {sup 16}N and the {sup 12}C(α,γ){sup 16}O cross section at astrophysical energies: A new experimental approach

Energy Technology Data Exchange (ETDEWEB)

Sanfilippo, S., E-mail: simone.sanfilippo@studium.unict.it [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S.Sofia 64, 95123 Catania (Italy); Cherubini, S.; Lattuada, M.; Spitaleri, C. [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S.Sofia 64, 95123 Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy); Hayakawa, S.; Di Pietro, A.; Figuera, P.; La Cognata, M. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Gulino, M. [INFN - Laboratori Nazionali del Sud, Catania, Italy and Università Kore, Enna (Italy); Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study, University of Tokyo, Wako Branch, Saitama (Japan); Kubono, S.; Wakabayashi, Y. [RIKEN Nishina Center, Wako, Saitama (Japan); Hashimoto, T. [RCNP, Osaka University, Osaka (Japan); Iwasa, N.; Okoda, Y.; Ushio, K. [Department of Physics, Tohoku University, Sendai (Japan); Teranishi, T. [Department of Physics, Kyushu University, Fukuoka (Japan); Mazzocco, M. [Dipartimento di Fisica e Astronomia, Università di Padova and INFN-Sez. Padova, Padova (Italy); and others

2015-02-24

The {sup 12}C(α,γ){sup 16}O reaction at energies corresponding to the quiescent helium burning in massive stars is regarded as one of the most important processes in nuclear astrophysics. Although this process has being studied for over four decades, our knowledge of its cross section at the energies of interest for astrophysics is still widely unsatisfactory. Indeed, no experimental data are available around 300 keV and in the energy region of astrophysical interest extrapolations are performed using some theoretical approaches, usually R-matrix calculations. Consequently, the published astrophysical factors range from 1 to 288 keVb for S{sub E1}(300) and 7 to 120 keVb for S{sub E2}(300), especially because of the unknown contribution coming from subthreshold resonances. To improve the reliability of these extrapolations, data from complementary experiments, such as elastic and quasi- elastic α scattering on {sup 12}C, α-transfer reactions to {sup 16}O, and {sup 16}N decay are usually included in the analysis. Here the β-delayed α decay of {sup 16}N is used to infer information on the {sup 12}C(α,γ){sup 16}O reaction and a new experimental technique is suggested.

Ongoing Space Physics - Astrophysics Connections

OpenAIRE

Eichler, David

2005-01-01

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

Experimental And Theoretical High Energy Physics Research At UCLA

Energy Technology Data Exchange (ETDEWEB)

Cousins, Robert D. [University of California Los Angeles

2013-07-22

This is the final report of the UCLA High Energy Physics DOE Grant No. DE-FG02- 91ER40662. This report covers the last grant project period, namely the three years beginning January 15, 2010, plus extensions through April 30, 2013. The report describes the broad range of our experimental research spanning direct dark matter detection searches using both liquid xenon (XENON) and liquid argon (DARKSIDE); present (ICARUS) and R&D for future (LBNE) neutrino physics; ultra-high-energy neutrino and cosmic ray detection (ANITA); and the highest-energy accelerator-based physics with the CMS experiment and CERN’s Large Hadron Collider. For our theory group, the report describes frontier activities including particle astrophysics and cosmology; neutrino physics; LHC interaction cross section calculations now feasible due to breakthroughs in theoretical techniques; and advances in the formal theory of supergravity.

The Trojan horse method in nuclear astrophysics

International Nuclear Information System (INIS)

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

2001-01-01

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

The fluorine destruction in stars: First experimental study of the {sup 19}F(p,{alpha}){sup 16}O reaction at astrophysical energies

Energy Technology Data Exchange (ETDEWEB)

La Cognata, M.; Mukhamedzhanov, A.; Spitaleri, C.; Indelicato, I.; Aliotta, M.; Burjan, V.; Cherubini, S.; Coc, A.; Gulino, M.; Hons, Z.; Kiss, G. G.; Kroha, V.; Lamia, L.; Mrazek, J.; Palmerini, S.; Piskor, S.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S. [INFN-LNS, Catania (Italy); Cyclotron Institute, Texas A and M University, College Station, Texas (United States); University of Catania and INFN-LNS, Catania (Italy); and others

2012-11-12

The {sup 19}F(p,{alpha}){sup 16}O reaction is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars and it might also play a role in hydrogendeficient post-AGB star nucleosynthesis. So far, available direct measurements do not reach the energy region of astrophysical interest (E{sub cm}{approx} 300 keV), because of the hindrance effect of the Coulomb barrier. The Trojan Horse (TH) method was thus used to access this energy region, by extracting the quasi-free contribution to the {sup 2}H({sup 19}F,{alpha}{sup 16}O)n reaction. The TH measurement of the {alpha}{sub 0} channel, which is the dominant one at such energies, shows the presence of resonant structures not observed before that cause an increase of the reaction rate at astrophysical temperatures up to a factor of 1.7, with potential important consequences for stellar nucleosynthesis.

75 FR 1087 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

Science.gov (United States)

2010-01-08

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting... Administration (NASA) and the U.S. Department of Energy (DOE) on issues within the field of astronomy and [[Page...

75 FR 22863 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

Science.gov (United States)

2010-04-30

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee... Administration (NASA) and the U.S. Department of Energy (DOE) on issues within the field of astronomy and...

77 FR 2095 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

Science.gov (United States)

2012-01-13

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting... Administration (NASA) and the U.S. Department of Energy (DOE) on issues within the field of astronomy and...

76 FR 58049 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

Science.gov (United States)

2011-09-19

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting... Administration (NASA) and the U.S. Department of Energy (DOE) on issues within the field of astronomy and...

[Experimental and theoretical high energy physics program

Energy Technology Data Exchange (ETDEWEB)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac{endash}Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e{sup +}e{sup {minus}} collisions at CERN; {bar p}{endash}p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab. (RWR)

[Experimental and theoretical high energy physics program

International Nuclear Information System (INIS)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac endash Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e + e - collisions at CERN; bar p endash p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab

[High energy particle physics at Purdue, 1989--1990

International Nuclear Information System (INIS)

Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1990-05-01

The theoretical and experimental high energy physics program is reviewed, including developments on particle detectors. Among the topics addressed are the following: the CLEO experiment; gamma ray astrophysics; highest-weight representations of affine Kac-Moody algebras; supersymmetric field theories; parity- violating effects and superconductivity in 2 + 1 dimensional supersymmetric QED; neutrino oscillations with applications to solar and supernova neutrinos; a search for the quark-gluon plasma using the Fermilab collider; the Solenoid Detector Collaboration at SSC; the high-resolution vertex chamber at TRISTAN; CP violation in e + e - →φ→K L K S ; deviations from Coulomb's Law; and the electric charge and equations of state of neutron stars

Progress report of a research program in experimental and theoretical high energy physics, 1 November 1993--31 October 1994

International Nuclear Information System (INIS)

Brandenberger, R.; Cutts, D.; Fried, H.M.

1994-01-01

This paper reports on the following tasks: theoretical high-energy physics; computational physics; interactions of leptons and hadrons from accelerator and astrophysical sources; and hadron collider and neutrino physics

Neutrinos at the forefront of elementary physics and astrophysics - Slides and abstracts

International Nuclear Information System (INIS)

Wark, D.; Cabrera, A.; Clark, K.; Cribier, M.; Rubbia, A.; Schwetz, T.; Hagedorn, C.; Bajc, B.; Thomas, J.; Nakahata, M.; Bravar, S.; Raffelt, G.; Mirizzi, A.; Serpico, P.; Drappeau, S.; Turk-Chieze, S.; Vignaud, D.; Kouchner, A.; Gay, P.; Baerwald, P.; Van Elewyck, V.; Branco, G.; Arbey, A.; Saviano, N.; Cirelli, M.; Verde, L.; Courtois, H.; Mauger, F.; Giunti, C.; Smadja, G.; Gascon, J.; Katsanevas, S.; Autiero, D.

2014-01-01

The conference has focused on neutrinos as a bridge between the two words of particle physics and astrophysics/cosmology with 3 main topics: -) the fundamental properties of neutrinos (neutrino masses and oscillations, mass hierarchy, neutrinoless double beta decay, neutrinos as Majorana particles, the search for CP violation in the leptonic sector, hints of physics beyond the standard model, the present experimental scenario and future large size experiments for neutrino oscillations and astro particle physics...); -) Neutrinos in astrophysics (neutrinos from the sun, neutrinos from Supernovae, high energy neutrinos... ); -) Neutrinos in cosmology (measurements of large scale structures, cosmological parameters, nucleosynthesis, dark matter, sterile neutrinos,...). This document is made up of the slides of the presentations and a few abstracts.

Highlights from e-EPS: the 2015 EPS High Energy Physics Prize winners

CERN Multimedia

Thomas Lohse, e-EPS News

2015-01-01

The EPS High Energy Physics Division announces the winners of its 2015 prizes, which will be awarded at the Europhysics Conference on High-Energy Physics (EPS-HEP 2015), Vienna (Austria) 22−29 July. Many people from CERN were among the winners.   The 2015 High Energy and Particle Physics Prize, for an outstanding contribution to High Energy Physics, is awarded to James D. Bjorken “for his prediction of scaling behaviour in the structure of the proton that led to a new understanding of the b interaction”, and to Guido Altarelli, Yuri L. Dokshitzer, Lev Lipatov, and Giorgio Parisi “for developing a probabilistic field theory framework for the dynamics of quarks and gluons, enabling a quantitative understanding of high-energy collisions involving hadrons”. The 2015 Giuseppe and Vanna Cocconi Prize, for an outstanding contribution to Particle Astrophysics and Cosmology in the past 15 years, is awarded to Francis Halzen “for his visiona...

Topics in Nuclear Astrophysics

International Nuclear Information System (INIS)

Chung, K.C.

1982-01-01

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

THE SZ EFFECT IN THE PLANCK ERA: ASTROPHYSICAL AND COSMOLOGICAL IMPACT

Directory of Open Access Journals (Sweden)

Sergio Colafrancesco

2013-12-01

Full Text Available The Sunyaev–Zel’dovich effect (SZE is a relevant probe for cosmology and particle astrophysics. The Planck Era marks a definite step forward in the use of this probe for astrophysics and cosmology. Astrophysical applications to galaxy clusters, galaxies, radiogalaxies and large-scale structures are discussed. Cosmological relevance for the Dark Energy equation of state, modified Gravity scenarios, Dark Matter search, cosmic magnetism and other cosmological applications is also reviewed. Future directions for the study of the SZE and its polarization are finally outlined.

Exploration of Plasma Jets Approach to High Energy Density Physics. Final report

Energy Technology Data Exchange (ETDEWEB)

Chen, Chiping [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2013-08-26

High-energy-density laboratory plasma (HEDLP) physics is an emerging, important area of research in plasma physics, nuclear physics, astrophysics, and particle acceleration. While the HEDLP regime occurs at extreme conditions which are often found naturally in space but not on the earth, it may be accessible by colliding high intensity plasmas such as high-energy-density plasma jets, plasmoids or compact toroids from plasma guns. The physics of plasma jets is investigated in the context of high energy density laboratory plasma research. This report summarizes results of theoretical and computational investigation of a plasma jet undergoing adiabatic compression and adiabatic expansion. A root-mean-squared (rms) envelope theory of plasma jets is developed. Comparison between theory and experiment is made. Good agreement between theory and experiment is found.

Investigating High Field Gravity using Astrophysical Techniques

International Nuclear Information System (INIS)

Bloom, Elliott D.

2008-01-01

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

Investigating High Field Gravity using Astrophysical Techniques

Energy Technology Data Exchange (ETDEWEB)

Bloom, Elliott D.; /SLAC

2008-02-01

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

Heavy ion irradiation of astrophysical ice analogs

International Nuclear Information System (INIS)

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

2009-01-01

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

Axion-like particles: possible hints and constraints from the high-energy Universe

International Nuclear Information System (INIS)

Brun, Pierre

2013-01-01

The high-energy Universe is potentially a great laboratory for searching new light bosons such as axion-like particles (ALPs). Cosmic sources are indeed the scene of violent phenomena that involve strong magnetic field and/or very long baselines, where the effects of the mixing of photons with ALPs could lead to observable effects. Two examples are archetypal of this fact, that are the Universe opacity to gamma-rays and the imprints of astrophysical magnetic turbulence in the energy spectra of high-energy sources. In the first case, hints for the existence of ALPs can be proposed whereas the second one is used to put constraints on the ALP mass and coupling to photons

Ultra-high energy signals from Hercules X-1

International Nuclear Information System (INIS)

Haines, T.J.; Alexandreas, D.E.; Allen, R.C.

1988-01-01

The expectation that high-energy neutrinos are emitted from astrophysical objects depends strongly on the observation of those objects in gamma-rays, especially at TeV and PeV energies. A search for bursts of gamma-ray events from Hercules X-1 at energies above 50 TeV yielded two significant bursts, both occurring on UT 24 July 1986. The events were pulsed with a period of 1.23568 s, significantly different from estimates of the pulsar period at that time. The probability that the signal is a random background fluctuation is about 2 /times/ 10/sup /minus/5/, not including the fact that there were two other independent observations of the source at nearly the same time. The muon content of the burst events is anomalous when compared with expectations of gamma-ray showers, perhaps signalling the onset of new physics at these energies. 9 refs., 4 figs., 1 tab

Model independent spectroscopic information from an analysis of peripheral direct radiative capture reaction and its application for an extrapolation of an astrophysical S-factor to stellar energies

International Nuclear Information System (INIS)

Igamov, S.B.; Tursunmuratov, T.M.; Yarmukhamedov, R.

2003-01-01

In this work, within the framework of the cluster potential approach we develop a method which can be used an independent source of getting information on the value of the nuclear vertex constant (NVC) (or respective asymptotical normalization coefficient (ANC)) from the analysis of the direct radiative capture cross section σ(E)(or the astrophysical S-factor S(E)) at extremely low energies by a model independent way as possible. The main idea of the proposed method is that at stellar energies peripheral direct radiative capture reaction of astrophysical interest proceeds mainly through the tail of the overlap integral, which is completely determined by the binding energy and the respective ANC (or NVC). The main advantage of the proposed method is that it allows us to determine both the absolute value of NVC (or ANC) and the astrophysical S-factor S(E) at solar energies (0-50 keV) by means of the analysis of the same experimental astrophysical S-factor S exp (E) in a correct self consistent way using the same potential both for the bound state and for scattering state. The method has been applied for an investigation of the direct radiative capture t(α, γ) 7 Li and 3 He(α, γ) 7 Be reactions at extremely low energies. At first, this method was used for analysis of the S exp (E) to determine values of the modulus squared of the NVC's (or the respective ANC's). The values of NVC's are presented. Then, the obtained NVC's are used by us for extrapolation of the S(E) of the reactions considered to stellar energies (E=0-50 keV) for the 3 He(α, γ) 7 Be reaction and for the t(α, γ) 7 Li reaction. The obtained results are compared with those other authors

High energy physics and cosmology

International Nuclear Information System (INIS)

Silk, J.I.

1991-01-01

This research will focus on the implications of recent theories and experiments in high energy physics of the evolution of the early universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including studies of the nature of dark matter and the signature of annihilations in the galactic halo, where the resulting γ-ray fluxes are potentially observable, and in stars, where stellar evolution may be affects. We will develop constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon, examining the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in both flat and curved cosmological models, and implications for observations of large-scale galaxy clustering and structure formation theories. We will also study spectral distortions in the microwave background radiation that are produced by exotic particle decays in the very early universe. We expect such astrophysical considerations to provide fruitful insights both into high-energy particle physics and into possible cosmological for the early universe

Color-color analysis of the optical counterparts of high energy sources

Czech Academy of Sciences Publication Activity Database

Šimon, Vojtěch; Hudec, René; Pizzichini, G.

2010-01-01

Roč. 81, č. 1 (2010), s. 356-361 ISSN 0037-8720. [Multifrequency behaviour of high energy cosmic sources. Vulcano, 25.05.2009-30.05. 2009] R&D Projects: GA ČR GA205/08/1207 Grant - others:ESA(XE) ESA- PECS project No. 98058 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-rays binaries * gamma rays * accretion, accretion disks Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Interpretation of astrophysical neutrinos observed by IceCube experiment by setting Galactic and extra-Galactic spectral components

CERN Document Server

Marinelli, Antonio; Grasso, Dario; Urbano, Alfredo; Valli, Mauro

2016-01-01

The last IceCube catalog of High Energy Starting Events (HESE) obtained with a livetime of 1347 days comprises 54 neutrino events equally-distributed between the three families with energies between 25 TeV and few PeVs. Considering the homogeneous flavors distribution (1:1:1) and the spectral features of these neutrinos the IceCube collaboration claims the astrophysical origin of these events with more than $5\\sigma$. The spatial distribution of cited events does not show a clear correlation with known astrophysical accelerators leaving opened both the Galactic and the extra-Galactic origin interpretations. Here, we compute the neutrino diffuse emission of our Galaxy on the basis of a recently proposed phenomenological model characterized by radially-dependent cosmic-ray (CR) transport properties. We show that the astrophysical spectrum measured by IceCube experiment can be well explained adding to the diffuse Galactic neutrino flux (obtained with this new model) a extra-Galactic component derived from the as...

Perspectives on High-Energy-Density Physics

Science.gov (United States)

Drake, R. Paul

2008-11-01

Much of 21st century plasma physics will involve work to produce, understand, control, and exploit very non-traditional plasmas. High-energy density (HED) plasmas are often examples, variously involving strong Coulomb interactions and few particles per Debeye sphere, dominant radiation effects, strongly relativistic effects, or strongly quantum-mechanical behavior. Indeed, these and other modern plasma systems often fall outside the early standard theoretical definitions of ``plasma''. This presentation will focus on two types of HED plasmas that exhibit non-traditional behavior. Our first example will be the plasmas produced by extremely strong shock waves. Shock waves are present across the entire realm of plasma densities, often in space or astrophysical contexts. HED shock waves (at pressures > 1 Mbar) enable studies in many areas, from equations of state to hydrodynamics to radiation hydrodynamics. We will specifically consider strongly radiative shocks, in which the radiative energy fluxes are comparable to the mechanical energy fluxes that drive the shocks. Modern HED facilities can produce such shocks, which are also present in dense, energetic, astrophysical systems such as supernovae. These shocks are also excellent targets for advanced simulations due to their range of spatial scales and complex radiation transport. Our second example will be relativistic plasmas. In general, these vary from plasmas containing relativistic particle beams, produced for some decades in the laboratory, to the relativistic thermal plasmas present for example in pulsar winds. Laboratory HED relativistic plasmas to date have been those produced by laser beams of irradiance ˜ 10^18 to 10^22 W/cm^2 or by accelerator-produced HED electron beams. These have applications ranging from generation of intense x-rays to production of proton beams for radiation therapy to acceleration of electrons. Here we will focus on electron acceleration, a spectacular recent success and a rare

Theoretical Research at the High Energy Frontier: Cosmology, Neutrinos, and Beyond

Energy Technology Data Exchange (ETDEWEB)

Krauss, Lawrence M; Vachaspati, Tanmay; Parikh, Maulik

2013-03-06

The DOE theory group grew from 2009-2012 from a single investigator, Lawrence Krauss, the PI on the grant, to include 3 faculty (with the addition of Maulik Parikh and Tanmay Vachaspati), and a postdoc covered by the grant, as well as partial support for a graduate student. The group has explored issues ranging from gravity and quantum field theory to topological defects, energy conditions in general relativity, primordial magnetic fields, neutrino astrophysics, quantum phases, gravitational waves from the early universe, dark matter detection schemes, signatures for dark matter at the LHC, and indirect astrophysical signatures for dark matter. In addition, we have run active international workshops each year, as well as a regular visitor program. As well, the PI's outreach activities, including popular books and articles, and columns for newspapers and magazines, as well as television and radio appearances have helped raise the profile of high energy physics internationally. The postdocs supported by the grant, James Dent and Roman Buniy have moved on successfully to a faculty positions in Louisiana and California.

Relativistic Astrophysics

International Nuclear Information System (INIS)

Font, J. A.

2015-01-01

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

Methods for Probing New Physics at High Energies

Science.gov (United States)

Denton, Peter B.

This dissertation covers two broad topics. The title, " Methods for Probing New Physics at High Energies," hopefully encompasses both of them. The first topic is located in part I of this work and is about integral dispersion relations. This is a technique to probe for new physics at energy scales near to the machine energy of a collider. For example, a hadron collider taking data at a given energy is typically only sensitive to new physics occurring at energy scales about a factor of five to ten beneath the actual machine energy due to parton distribution functions. This technique is sensitive to physics happening directly beneath the machine energy in addition to the even more interesting case: directly above. Precisely where this technique is sensitive is one of the main topics of this area of research. The other topic is located in part II and is about cosmic ray anisotropy at the highest energies. The unanswered questions about cosmic rays at the highest energies are numerous and interconnected in complicated ways. What may be the first piece of the puzzle to fall into place is determining their sources. This work looks to determine if and when the use of spherical harmonics becomes sensitive enough to determine these sources. The completed papers for this work can be found online. For part I on integral dispersion relations see reference published in Physical Review D. For part II on cosmic ray anisotropy, there are conference proceedings published in the Journal of Physics: Conference Series. The analysis of the location of an experiment on anisotropy reconstruction is, and the comparison of different experiments' abilities to reconstruct anisotropies is published in The Astrophysical Journal and the Journal of High Energy Astrophysics respectively. While this dissertation is focused on three papers completed with Tom Weiler at Vanderbilt University, other papers were completed at the same time. The first was with Nicusor Arsene, Lauretiu Caramete, and

Nuclear astrophysics of the sun

International Nuclear Information System (INIS)

Kocharov, G.E.

1980-01-01

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

The gluon condensation at high energy hadron collisions

Energy Technology Data Exchange (ETDEWEB)

Zhu, Wei, E-mail: weizhu@mail.ecnu.edu.cn [Department of Physics, East China Normal University, Shanghai 200241 (China); Lan, Jiangshan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2017-03-15

We report that the saturation/CGC model of gluon distribution is unstable under action of the chaotic solution in a nonlinear QCD evolution equation, and it evolves to the distribution with a sharp peak at the critical momentum. We find that this gluon condensation is caused by a new kind of shadowing–antishadowing effects, and it leads to a series of unexpected effects in high energy hadron collisions including astrophysical events. For example, the extremely intense fluctuations in the transverse-momentum and rapidity distributions of the gluon jets present the gluon-jet bursts; a sudden increase of the proton–proton cross sections may fill the GZK suppression; the blocking QCD evolution will restrict the maximum available energy of the hadron–hadron colliders.

The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

International Nuclear Information System (INIS)

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

2014-01-01

The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally

The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

Energy Technology Data Exchange (ETDEWEB)

Tumino, A.; Gulino, M. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Università degli Studi di Enna Kore, Enna (Italy); Spitaleri, C.; Cherubini, S.; Romano, S. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Cognata, M. La; Pizzone, R. G.; Rapisarda, G. G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

2014-05-09

The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.

The light element formation: a signature of high energy nuclear astrophysics

International Nuclear Information System (INIS)

Audouze, J.; Meneguzzi, M.; Reeves, H.

1976-01-01

Light elements D, 6 Li, 9 Be, 10 B and 11 B (and possibly also 7 Li) are not produced by the general nucleosynthetic processes occurring in stars. They appear to be synthesized by high energy processes occuring either during the interaction of galactic cosmic rays with the interstellar medium or in supernovae envelopes. These formation processes are discussed. It is emphasized that the most coherent scenario regarding the formation of the light elements is obtained by taking also into account the nuclear processes which may have occurred during hot phases of the early Universe (Big Bang). Implications on chemical evolution of galaxies and on cosmology are briefly recalled. (Auth.)

High Energy Astronomical Data Processing and Analysis via the Internet

Science.gov (United States)

Valencic, Lynne A.; Snowden, S.; Pence, W.

2012-01-01

The HEASARC at NASA Goddard Space Flight Center and the US XMM-Newton GOF has developed Hera, a data processing facility for analyzing high energy astronomical data over the internet. Hera provides all the disk space and computing resources needed to do general processing of and advanced research on publicly available data from High Energy Astrophysics missions. The data and data products are kept on a server at GSFC and can be downloaded to a user's local machine. Further, the XMM-GOF has developed scripts to streamline XMM data reduction. These are available through Hera, and can also be downloaded to a user's local machine. These are free services provided to students, educators, and researchers for educational and research purposes.

[Experimental and theoretical high energy physics program]. [Purdue Univ. , West Lafayette, Indiana

Energy Technology Data Exchange (ETDEWEB)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac[endash]Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e[sup +]e[sup [minus

Photoneutron Reaction Data for Nuclear Physics and Astrophysics

Science.gov (United States)

Utsunomiya, Hiroaki; Renstrøm, Therese; Tveten, Gry Merete; Gheorghe, Ioana; Filipescu, Dan Mihai; Belyshev, Sergey; Stopani, Konstantin; Wang, Hongwei; Fan, Gongtao; Lui, Yiu-Wing; Symochko, Dmytro; Goriely, Stephane; Larsen, Ann-Cecilie; Siem, Sunniva; Varlamov, Vladimir; Ishkhanov, Boris; Glodariu, Tudor; Krzysiek, Mateusz; Takenaka, Daiki; Ari-izumi, Takashi; Amano, Sho; Miyamoto, Shuji

2018-05-01

We discuss the role of photoneutron reaction data in nuclear physics and astrophysics in conjunction with the Coordinated Research Project of the International Atomic Energy Agency with the code F41032 (IAEA-CRP F41032).

Special relativity in general frames from particles to astrophysics

CERN Document Server

Gourgoulhon, Éric

2013-01-01

Special relativity is the basis of many fields in modern physics: particle physics, quantum field theory, high-energy astrophysics, etc. This theory is presented here by adopting a four-dimensional point of view from the start. An outstanding feature of the book is that it doesn’t restrict itself to inertial frames but considers accelerated and rotating observers. It is thus possible to treat physical effects such as the Thomas precession or the Sagnac effect in a simple yet precise manner. In the final chapters, more advanced topics like tensorial fields in spacetime, exterior calculus and relativistic hydrodynamics are addressed. In the last, brief chapter the author gives a preview of gravity and shows where it becomes incompatible with Minkowsky spacetime. Well illustrated and enriched by many historical notes, this book also presents many applications of special relativity, ranging from particle physics (accelerators, particle collisions, quark-gluon plasma) to astrophysics (relativistic jets, active g...

On the saturation of astrophysical dynamos

DEFF Research Database (Denmark)

Dorch, Bertil; Archontis, Vasilis

2004-01-01

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

Physics and astrophysics with gamma-ray telescopes

Energy Technology Data Exchange (ETDEWEB)

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

2012-08-15

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

Cosmic Ray Astrophysics using The High Altitude Water Cherenkov (HAWC Observatory in México

Directory of Open Access Journals (Sweden)

de la Fuente Eduardo

2017-01-01

Full Text Available The High-Altitude Water Cherenkov (HAWC TeV gamma–ray Observatory in México is ready to search and study gamma-ray emission regions, extremely high-energy cosmic-ray sources, and to identify transient phenomena. With a better Gamma/Hadron rejection method than other similar experiments, it will play a key role in triggering multi–wavelength and multi–messenger studies of active galaxies (AGN, gamma-ray bursts (GRB, supernova remnants (SNR, pulsar wind nebulae (PWN, Galactic Plane Sources, and Cosmic Ray Anisotropies. It has an instantaneous field-of-view of ∼2 str, equivalent to 15% of the whole sky and continuous operation (24 hours per day. The results obtained by HAWC–111 (111 detectors in operation were presented on the proceedings of the International Cosmic Ray Conference 2015 and in [1]. The results obtained by HAWC–300 (full operation are now under analysis and will be published in forthcoming papers starting in 2017 (see preliminary results on http://www.hawc-observatory.org/news/. Here we present the HAWC contributions on cosmic ray astrophysics via anisotropies studies, summarizing the HAWC detector and its upgrading by the installation of “outriggers”.

Indirect Techniques in Nuclear Astrophysics. Asymptotic Normalization Coefficient and Trojan Horse

International Nuclear Information System (INIS)

Mukhamedzhanov, A.M.; Blokhintsev, L.D.; Brown, S.

2007-01-01

We address two important indirect techniques, the asymptotic normalization coefficient (ANC) and the Trojan Horse (TH) methods. We discuss the application of the ANC technique to determine the astrophysical factor for the 13 C(α, n) 16 O reaction which is one of the neutron generators for the s processes in AGB stars. The TH method is a unique indirect technique allowing one to measure astrophysical S factors for rearrangement reactions down to astrophysically relevant energies. We derive equations connecting the cross sections for the binary direct and resonant reactions determined from the indirect TH reactions to direct cross sections measurements

AN UPDATED 6Li(p, α)3He REACTION RATE AT ASTROPHYSICAL ENERGIES WITH THE TROJAN HORSE METHOD

International Nuclear Information System (INIS)

Lamia, L.; Spitaleri, C.; Sergi, M. L.; Pizzone, R. G.; Tumino, A.; La Cognata, M.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.; Pappalardo, L.

2013-01-01

The lithium problem influencing primordial and stellar nucleosynthesis is one of the most interesting unsolved issues in astrophysics. 6 Li is the most fragile of lithium's stable isotopes and is largely destroyed in most stars during the pre-main-sequence (PMS) phase. For these stars, the convective envelope easily reaches, at least at its bottom, the relatively low 6 Li ignition temperature. Thus, gaining an understanding of 6 Li depletion also gives hints about the extent of convective regions. For this reason, charged-particle-induced reactions in lithium have been the subject of several studies. Low-energy extrapolations of these studies provide information about both the zero-energy astrophysical S(E) factor and the electron screening potential, U e . Thanks to recent direct measurements, new estimates of the 6 Li(p, α) 3 He bare-nucleus S(E) factor and the corresponding U e value have been obtained by applying the Trojan Horse method to the 2 H( 6 Li, α 3 He)n reaction in quasi-free kinematics. The calculated reaction rate covers the temperature window 0.01 to 2T 9 and its impact on the surface lithium depletion in PMS models with different masses and metallicities has been evaluated in detail by adopting an updated version of the FRANEC evolutionary code.

The galactic contribution to IceCube's astrophysical neutrino flux

Energy Technology Data Exchange (ETDEWEB)

Denton, Peter B. [Niels Bohr International Academy, University of Copenhagen, The Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen (Denmark); Marfatia, Danny [Department of Physics and Astronomy, University of Hawaii at Manoa, 2505 Correa Rd., Honolulu, HI 96822 (United States); Weiler, Thomas J., E-mail: peterbd1@gmail.com, E-mail: dmarf8@hawaii.edu, E-mail: tom.weiler@vanderbilt.edu [Department of Physics and Astronomy, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37235 (United States)

2017-08-01

High energy neutrinos have been detected by IceCube, but their origin remains a mystery. Determining the sources of this flux is a crucial first step towards multi-messenger studies. In this work we systematically compare two classes of sources with the data: galactic and extragalactic. We assume that the neutrino sources are distributed according to a class of Galactic models. We build a likelihood function on an event by event basis including energy, event topology, absorption, and direction information. We present the probability that each high energy event with deposited energy E {sub dep}>60 TeV in the HESE sample is Galactic, extragalactic, or background. For Galactic models considered the Galactic fraction of the astrophysical flux has a best fit value of 1.3% and is <9.5% at 90% CL. A zero Galactic flux is allowed at <1σ.

NASA Astrophysics Funds Strategic Technology Development

Science.gov (United States)

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

2016-01-01

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

Physical-chemical processes of astrophysical interest: nitrogen chemistry

International Nuclear Information System (INIS)

Loison, Jean-Christophe; Hickson, Kevin; Hily-Blant, Pierre; Faure, Alexandre; Vuitton, Veronique; Bacmann, A.; Maret, Sebastien; Legal, Romane; Rist, Claire; Roncero, Octavio; Larregaray, Pascal; Hochlaf, Majdi; Senent, M. L.; Capron, Michael; Biennier, Ludovic; Carles, Sophie; Bourgalais, Jeremy; Le Picard, Sebastien; Cordier, Daniel; Guillemin, Jean-Claude; Trolez, Yann; Bertin, M.; Poderoso, H.A.M.; Michaut, X.; Jeseck, P.; Philippe, L.; Fillion, J.H.; Fayolle, E.C.; Linnartz, H.; Romanzin, C.; Oeberg, K.I.; Roueff, Evelyne; Pagani, Laurent; Padovani, Marco; Wakelam, Veronique; Honvault, Beatrice; Zvereva-Loete, Natalia; Ouk, Chanda-Malis; Scribano, Yohann; Hartmann, J.M.; Pineau des Forets, Guillaume; Hernandez, Mario; Lique, Francois; Kalugina, Yulia N.; Stoecklin, T.; Hochlaf, M.; Crespos, C.; Larregaray, P.; Martin-Gondre, L.; Petuya, R.; Quintas Sanchez, E.L.; Zanchet, Alexandre; Rodriguez-Lazcano, Yamilet; Mate, Belen

2013-06-01

This document contains the programme and abstracts of contributions to a workshop on nitrogen chemistry within an astrophysical perspective. These contributions have been presented in sessions: Introduction (opening lecture, experimental approaches to molecular astrophysics, theoretical approaches to astrophysics, observations in molecular astrophysics), Physical-chemical theory of the gas phase (time-dependent approach in elementary activity, statistic approach in elementary activity in the case of the N+H_2 reaction, potential energy surfaces for inelastic and reactive collisions, collision rate for N_2H"+, ortho/para selection rules in the chemistry of nitrogen hydrides, cyanides/iso-cyanides excitation in the ISM, CN excitation, radiative association with N_2H as new interstellar anion, ro-vibratory excitation of HCN) Laboratory astrophysics (measurement of reaction products in the CRESUSOL project, reactivity of the CN- anion, N_2 photo-desorption in ices, CRESU study of nitrogen chemistry, chemistry of nitrogen complex molecules), Observations and chemistry of astrophysical media (the problem of interstellar nitrogen fractioning, abundance of N_2 in proto-stellar cores, HNC in Titan atmosphere and nitrogen-related mechanisms in hot Jupiters, HCN and HNC in dark clouds or how theoretical modelling helps in interpreting observations, nitrogen chemistry in cold clouds, deuteration of nitrogen hydrides, nitrogen in interstellar ices, biochemical molecules on Titan, coupling between excitation and chemistry, radiative transfer of nitrogen hydrides, ortho/para chemistry of nitrogen hydrides), Physical-chemical theory of gas-grain interactions (nitrogen reactivity on surfaces, IR spectra of ices of NH_3 and NH_3/N_2 mixtures)

Laboratory Astrophysics Division of The AAS (LAD)

Science.gov (United States)

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

2012-10-01

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

Laboratory Astrophysics Division of the AAS (LAD)

Science.gov (United States)

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

2012-01-01

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

The collective emission of electromagnetic waves from astrophysical jets - Luminosity gaps, BL Lacertae objects, and efficient energy transport

Science.gov (United States)

Baker, D. N.; Borovsky, Joseph E.; Benford, Gregory; Eilek, Jean A.

1988-01-01

A model of the inner portions of astrophysical jets is constructed in which a relativistic electron beam is injected from the central engine into the jet plasma. This beam drives electrostatic plasma wave turbulence, which leads to the collective emission of electromagnetic waves. The emitted waves are beamed in the direction of the jet axis, so that end-on viewing of the jet yields an extremely bright source (BL Lacertae object). The relativistic electron beam may also drive long-wavelength electromagnetic plasma instabilities (firehose and Kelvin-Helmholtz) that jumble the jet magnetic field lines. After a sufficient distance from the core source, these instabilities will cause the beamed emission to point in random directions and the jet emission can then be observed from any direction relative to the jet axis. This combination of effects may lead to the gap turn-on of astrophysical jets. The collective emission model leads to different estimates for energy transport and the interpretation of radio spectra than the conventional incoherent synchrotron theory.

Minicourses in Astrophysics, Modular Approach, Vol. II.

Science.gov (United States)

Illinois Univ., Chicago.

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

Photoneutron Reaction Data for Nuclear Physics and Astrophysics

Directory of Open Access Journals (Sweden)

Utsunomiya Hiroaki

2018-01-01

Full Text Available We discuss the role of photoneutron reaction data in nuclear physics and astrophysics in conjunction with the Coordinated Research Project of the International Atomic Energy Agency with the code F41032 (IAEA-CRP F41032.

CRKSPH: A new meshfree hydrodynamics method with applications to astrophysics

Science.gov (United States)

Owen, John Michael; Raskin, Cody; Frontiere, Nicholas

2018-01-01

The study of astrophysical phenomena such as supernovae, accretion disks, galaxy formation, and large-scale structure formation requires computational modeling of, at a minimum, hydrodynamics and gravity. Developing numerical methods appropriate for these kinds of problems requires a number of properties: shock-capturing hydrodynamics benefits from rigorous conservation of invariants such as total energy, linear momentum, and mass; lack of obvious symmetries or a simplified spatial geometry to exploit necessitate 3D methods that ideally are Galilean invariant; the dynamic range of mass and spatial scales that need to be resolved can span many orders of magnitude, requiring methods that are highly adaptable in their space and time resolution. We have developed a new Lagrangian meshfree hydrodynamics method called Conservative Reproducing Kernel Smoothed Particle Hydrodynamics, or CRKSPH, in order to meet these goals. CRKSPH is a conservative generalization of the meshfree reproducing kernel method, combining the high-order accuracy of reproducing kernels with the explicit conservation of mass, linear momentum, and energy necessary to study shock-driven hydrodynamics in compressible fluids. CRKSPH's Lagrangian, particle-like nature makes it simple to combine with well-known N-body methods for modeling gravitation, similar to the older Smoothed Particle Hydrodynamics (SPH) method. Indeed, CRKSPH can be substituted for SPH in existing SPH codes due to these similarities. In comparison to SPH, CRKSPH is able to achieve substantially higher accuracy for a given number of points due to the explicitly consistent (and higher-order) interpolation theory of reproducing kernels, while maintaining the same conservation principles (and therefore applicability) as SPH. There are currently two coded implementations of CRKSPH available: one in the open-source research code Spheral, and the other in the high-performance cosmological code HACC. Using these codes we have applied

Foundations of high-energy-density physics physical processes of matter at extreme conditions

CERN Document Server

Larsen, Jon

2017-01-01

High-energy-density physics explores the dynamics of matter at extreme conditions. This encompasses temperatures and densities far greater than we experience on Earth. It applies to normal stars, exploding stars, active galaxies, and planetary interiors. High-energy-density matter is found on Earth in the explosion of nuclear weapons and in laboratories with high-powered lasers or pulsed-power machines. The physics explored in this book is the basis for large-scale simulation codes needed to interpret experimental results whether from astrophysical observations or laboratory-scale experiments. The key elements of high-energy-density physics covered are gas dynamics, ionization, thermal energy transport, and radiation transfer, intense electromagnetic waves, and their dynamical coupling. Implicit in this is a fundamental understanding of hydrodynamics, plasma physics, atomic physics, quantum mechanics, and electromagnetic theory. Beginning with a summary of the topics and exploring the major ones in depth, thi...

Research in high energy physics. Annual technical progress report, December 1, 1993--November 30, 1998

International Nuclear Information System (INIS)

Olsen, S.L.; Tata, X.

1996-01-01

The high energy physics research program at the University of Hawaii is directed toward the study of the properties of the elementary particles and the application of the results of these studies to the understanding of the physical world. Experiments using high energy accelerators are aimed at searching for new particles, testing current theories, and measuring properties of the known particles. Experiments using cosmic rays address particle physics and astrophysical issues. Theoretical physics research evaluates experimental results in the context of existing theories and projects the experimental consequences of proposed new theories

Polar Balloon Experiment for Astrophysics Research (Polar BEAR)

Science.gov (United States)

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

16th Workshop on High Energy Spin Physics

CERN Document Server

2016-01-01

The Workshop will cover a wide range of spin phenomena at high and intermediate energies such as: recent experimental data on spin physics the nucleon spin structure and GPD's spin physics and QCD spin physics in the Standard Model and beyond T-odd spin effects polarization and heavy ion physics spin in gravity and astrophysics the future spin physics facilities spin physics at NICA polarimeters for high energy polarized beams acceleration and storage of polarized beams the new polarization technology related subjects The Workshop will be held in the Bogoliubov Laboratory of Theoretical Physics of the Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia. The program of the workshop will include plenary and parallel (if necessary) sessions. Plenary sessions will be held in the Conference Hall. Parallel sections will take place in the same building. There will be invited talks (up to 40 min) and original reports (20 min). The invited speakers will present new experimental and theoretical re...

Probing neutrino dark energy with extremely high-energy cosmic neutrinos

International Nuclear Information System (INIS)

Ringwald, A.; Schrempp, L.

2006-06-01

Recently, a new non-Standard Model neutrino interaction mediated by a light scalar field was proposed, which renders the big-bang relic neutrinos of the cosmic neutrino background a natural dark energy candidate, the so-called Neutrino Dark Energy. As a further consequence of this interaction, the neutrino masses become functions of the neutrino energy densities and are thus promoted to dynamical, time/redshift dependent quantities. Such a possible neutrino mass variation introduces a redshift dependence into the resonance energies associated with the annihilation of extremely high-energy cosmic neutrinos on relic anti-neutrinos and vice versa into Z-bosons. In general, this annihilation process is expected to lead to sizeable absorption dips in the spectra to be observed on earth by neutrino observatories operating in the relevant energy region above 10 13 GeV. In our analysis, we contrast the characteristic absorption features produced by constant and varying neutrino masses, including all thermal background effects caused by the relic neutrino motion. We firstly consider neutrinos from astrophysical sources and secondly neutrinos originating from the decomposition of topological defects using the appropriate fragmentation functions. On the one hand, independent of the nature of neutrino masses, our results illustrate the discovery potential for the cosmic neutrino background by means of relic neutrino absorption spectroscopy. On the other hand, they allow to estimate the prospects for testing its possible interpretation as source of Neutrino Dark Energy within the next decade by the neutrino observatories ANITA and LOFAR. (Orig.)

Experimental simulation of lightning, interacting explosions and astrophysical jets with pulsed lasers

International Nuclear Information System (INIS)

Villagran-Muniz, M; Sobral, H; Navarro-Gonzalez, R; Velazquez, P F; Raga, A C

2003-01-01

Tabletop laboratory experiments have been used to simulate natural lightning, interacting explosions and astrophysical jets. When a high-energy laser pulse is focused in air, a laser-induced plasma (LIP) is produced, that generates a shock wave and an adiabatic expansion of the gas. In our work we have used LIPs in order to simulate lightning, for the study of chemical reactions relevant to atmospheric science. Several diagnostics have been applied to our LIPs, such as deflectometry, shadowgraphy and interferometry, which yield full spatial information of the process (electron density and temperature, the position of the shock wave fronts and the expansion of the hot gas), with a time resolution that ranges from nanoseconds to milliseconds. A new diagnostic alternative was implemented for shadowgraphy, which uses either continuous lasers or conventional light sources. The experimental results have been reproduced by hydrodynamic codes that we have developed. With astrophysical applications in mind, we have simulated and diagnosed the interaction of two explosions, with the aforementioned techniques. For this purpose, two LIPs are synchronized and diagnosed spatially and temporarily. Also, by producing the LIP in a glass sphere with a nozzle that ejects a shock wave and hot gas, we are able to simulate astrophysical jets. With such experiments, astrophysical models developed by us have been validated, showing excellent agreement between experiments and numerical simulations

Astrophysical fluid dynamics

Science.gov (United States)

Ogilvie, Gordon I.

2016-06-01

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

A modified likelihood-method to search for point-sources in the diffuse astrophysical neutrino-flux in IceCube

Energy Technology Data Exchange (ETDEWEB)

Reimann, Rene; Haack, Christian; Leuermann, Martin; Raedel, Leif; Schoenen, Sebastian; Schimp, Michael; Wiebusch, Christopher [III. Physikalisches Institut, RWTH Aachen (Germany); Collaboration: IceCube-Collaboration

2015-07-01

IceCube, a cubic-kilometer sized neutrino detector at the geographical South Pole, has recently measured a flux of high-energy astrophysical neutrinos. Although this flux has now been observed in multiple analyses, no point sources or source classes could be identified yet. Standard point source searches test many points in the sky for a point source of astrophysical neutrinos individually and therefore produce many trials. Our approach is to additionally use the measured diffuse spectrum to constrain the number of possible point sources and their properties. Initial studies of the method performance are shown.

Solar astrophysics: ghettosis from, or symbiosis with, stellar and galactic astrophysics

Energy Technology Data Exchange (ETDEWEB)

Pecker, J C; Thomas, R N [Centre National de la Recherche Scientifique, 75 - Paris (France). Inst. d' Astrophysique

1976-07-01

The authors summarize how the solar-stellar symbiotic approach, an astrophysical research method, has led to the modeling of a star as a concentration of matter and energy. The observational aspect of the method is to discover an 'anomalous' feature, in either the Sun, where the feature is small, or in an unusual or exceptional star, where the feature is large. The theoretical aspect of the method is to discover some physical inconsistency in theoretical models of some phenomenon or in theoretical basis for some diagnostic method, and attempt to develop a better approach, guided by the observational application.

Challenges and opportunities in laboratory plasma astrophysics

Science.gov (United States)

Drake, R. Paul

2017-06-01

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

Astrophysics of Red Supergiants

Science.gov (United States)

Levesque, Emily M.

2017-12-01

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

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. N. Kameswara Rao. Articles written in Journal of Astrophysics and Astronomy. Volume 26 Issue 2-3 June-September 2005 pp 331-338. High Resolution Stellar Spectroscopy with VBT Echelle Spectrometer · N. Kameswara Rao S. Sriram K. Jayakumar F. Gabriel.

Point source search techniques in ultra high energy gamma ray astronomy

International Nuclear Information System (INIS)

Alexandreas, D.E.; Biller, S.; Dion, G.M.; Lu, X.Q.; Yodh, G.B.; Berley, D.; Goodman, J.A.; Haines, T.J.; Hoffman, C.M.; Horch, E.; Sinnis, C.; Zhang, W.

1993-01-01

Searches for point astrophysical sources of ultra high energy (UHE) gamma rays are plagued by large numbers of background events from isotropic cosmic rays. Some of the methods that have been used to estimate the expected number of background events coming from the direction of a possible source are found to contain biases. Search techniques that avoid this problem are described. There is also a discussion of how to optimize the sensitivity of a search to emission from a point source. (orig.)

Astrophysical Hydrodynamics An Introduction

CERN Document Server

Shore, Steven N

2007-01-01

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

Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

Science.gov (United States)

Ando, Shin'ichiro; Baret, Bruny; Bartos, Imre; Bouhou, Boutayeb; Chassande-Mottin, Eric; Corsi, Alessandra; Di Palma, Irene; Dietz, Alexander; Donzaud, Corinne; Eichler, David; Finley, Chad; Guetta, Dafne; Halzen, Francis; Jones, Gareth; Kandhasamy, Shivaraj; Kotake, Kei; Kouchner, Antoine; Mandic, Vuk; Márka, Szabolcs; Márka, Zsuzsa; Moscoso, Luciano; Papa, Maria Alessandra; Piran, Tsvi; Pradier, Thierry; Romero, Gustavo E.; Sutton, Patrick; Thrane, Eric; Van Elewyck, Véronique; Waxman, Eli

2013-10-01

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from the inner regions of the astrophysical engines from which they are emitted (and from which photons and charged cosmic rays cannot reach us). For the same reasons, such messengers could also reveal new, hidden sources that have not been observed by conventional photon-based astronomy. Coincident observation of GWs and HENs may thus play a critical role in multimessenger astronomy. This is particularly true at the present time owing to the advent of a new generation of dedicated detectors: the neutrino telescopes IceCube at the South Pole and ANTARES in the Mediterranean Sea, as well as the GW interferometers Virgo in Italy and LIGO in the United States. Starting from 2007, several periods of concomitant data taking involving these detectors have been conducted. More joint data sets are expected with the next generation of advanced detectors that are to be operational by 2015, with other detectors, such as KAGRA in Japan, joining in the future. Combining information from these independent detectors can provide original ways of constraining the physical processes driving the sources and also help confirm the astrophysical origin of a GW or HEN signal in case of coincident observation. Given the complexity of the instruments, a successful joint analysis of this combined GW and HEN observational data set will be possible only if the expertise and knowledge of the data is shared between the two communities. This Colloquium aims at providing an overview of both theoretical and experimental state of the art and perspectives for GW and HEN

High Energy Astronomy Observatory (HEAO)-2

Science.gov (United States)

1982-01-01

This artist's concept depicts the High Energy Astronomy Observatory (HEAO)-2 in orbit. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

Scaling law in laboratory astrophysics

International Nuclear Information System (INIS)

Xia Jiangfan; Zhang Jie

2001-01-01

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

Determination of the S18 astrophysical factor for 8B(p,γ)9C from the breakup of 9C at intermediate energies

International Nuclear Information System (INIS)

Trache, L.; Mukhamedzhanov, A.M.; Tribble, R.E.; Carstoiu, F.

2002-06-01

We have used existing data on the one-proton-removal cross section of 9 C at 285 MeV/u and Glauber model calculations to extract the asymptotic normalization coefficient for the wave function of the last proton in the ground state of 9 C. The calculations are done first using folded potentials starting from two different effective nucleon-nucleon interactions and second in the optical limit using three nucleon-nucleon interactions, and the results are found to be consistent, with no new parameters adjusted. We find C 2 (p 3/2 ) + C 2 (p 1/2 ) = 1.22±0.13 fm -1 . From this result we obtain the astrophysical factor for the proton radiative capture reaction 8 B(p,γ) 9 C as S 18 (0) = 46 ± 6 eV.b. The calculated energy dependence of the astrophysical S-factor for the energy region E cm = 0 - 0.8 MeV and the reaction rates for T 9 = 0 - 1 are included. (authors)

Nuclear astrophysics

International Nuclear Information System (INIS)

Haxton, W.C.

1992-01-01

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

Critical ionisation velocity effects in astrophysical plasmas

International Nuclear Information System (INIS)

Raadu, M.A.

1979-08-01

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

Research on high energy density plasmas and applications

International Nuclear Information System (INIS)

1999-01-01

Recently, technologies on lasers, accelerators, and pulse power machines have been significantly advanced and input power density covers the intensity range from 10 10 W/cm 2 to higher than 10 20 W/cm 2 . As the results, high pressure gas and solid targets can be heated up to very high temperature to create hot dense plasmas which have never appeared on the earth. The high energy density plasmas opened up new research fields such as inertial confinement fusion, high brightness X-ray radiation sources, interiors of galactic nucleus,supernova, stars and planets, ultra high pressure condensed matter physics, plasma particle accelerator, X-ray laser, and so on. Furthermore, since these fields are intimately connected with various industrial sciences and technologies, the high energy density plasma is now studied in industries, government institutions, and so on. This special issue of the Journal of Plasma Physics and Nuclear Fusion Research reviews the high energy density plasma science for the comprehensive understanding of such new fields. In May, 1998, the review committee for investigating the present status and the future prospects of high energy density plasma science was established in the Japan Society of Plasma Science and Nuclear Fusion Research. We held three committee meetings to discuss present status and critical issues of research items related to high energy density plasmas. This special issue summarizes the understandings of the committee. This special issue consists of four chapters: They are Chapter 1: Physics important in the high energy density plasmas, Chapter 2: Technologies related to the plasma generation; drivers such as lasers, pulse power machines, particle beams and fabrication of various targets, Chapter 3: Plasma diagnostics important in high energy density plasma experiments, Chapter 4: A variety of applications of high energy density plasmas; X-ray radiation, particle acceleration, inertial confinement fusion, laboratory astrophysics

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. P. Kharb. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 34 Review. From Nearby Low Luminosity AGN to High Redshift Radio Galaxies: Science Interests with Square Kilometre Array · P. Kharb D. V. Lal V. Singh J.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. G. Srinivasan. Articles written in Journal of Astrophysics and Astronomy. Volume 25 Issue 3-4 September-December 2004 pp 143-183. A High Galactic Latitude HI 21 cm-line Absorption Survey using the GMRT: I. Observations and Spectra · Rekhesh Mohan K. S. ...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 29; Issue 1-2 ... emission and the thermal conduction belowto the transition region. ... s provide the required heating rate to balance the energy losses in the ...

AstroMail: Electronic mail for the astrophysics community

Science.gov (United States)

Scherrer, Phillip H.; Bogart, Richard S.

1993-01-01

As part of the NASA Science Internet User Support Services program, NASA Goddard was interested in R&D which could extend the SolarMail system developed by members of the Wilcox Space Observatory at Stanford University to support a larger astrophysics user community. Specific objectives of the R&D effort were to include: a clone of the existing SolarMail system with additional documentation, enabling a parallel mail system to be established by populating the database; a cloned version of SolarMail functioning with a user database similar to that of the High Energy Astrophysics Division (HEAD) of the American Astronomical Society; a report on the status and surveyed usage of SolarMail and its clones into an extendable distributed mail system to serve as the basis for AstroMail, including a draft declaration of policy; a prototype AstroMail system based on the above specifications and including at least SolarMail and one of its clones supporting a set of astronomy user databases as subsets; and a report on the status of the prototype AstroMail with recommendations for future modifications to AstroMail.

C{sub 60} AS A PROBE FOR ASTROPHYSICAL ENVIRONMENTS

Energy Technology Data Exchange (ETDEWEB)

Brieva, A. C.; Jäger, C.; Huisken, F. [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Gredel, R.; Henning, T., E-mail: aab01@alumni.aber.ac.uk [Max Planck Institute for Astronomy (MPIA), Königstuhl 17, D-69117 Heidelberg (Germany)

2016-08-01

The C{sub 60} molecule has been recently detected in a wide range of astrophysical environments through its four active intramolecular vibrational modes ( T {sub 1u}) near 18.9, 17.4, 8.5, and 7.0 μ m. The strengths of the mid-infrared emission bands have been used to infer astrophysical conditions in the fullerene-rich regions. Widely varying values of the relative intrinsic strengths (RIS) of these four bands are reported in laboratory and theoretical papers, which impedes the derivation of the excitation mechanism of C{sub 60} in the astrophysical sources. The spectroscopic analysis of the C{sub 60} samples produced with our method delivers highly reproducible RIS values of 100, 25 ± 1, 26 ± 1 and 40 ± 4. A comparison of the inferred C{sub 60} emission band strengths with the astrophysical data shows that the observed strengths cannot be explained in terms of fluorescent or thermal emission alone. The large range in the observed 17.4 μ m/18.9 μ m emission ratios indicates that either the emission bands contain significant contributions from emitters other than C{sub 60}, or that the population distribution among the C{sub 60} vibrational modes is affected by physical processes other than thermal or UV excitation, such as chemo-luminescence from nascent C{sub 60} or possibly Poincaré fluorescence resulting from an inverse internal energy conversion. We have carefully analyzed the effect of the weakly active fundamental modes and second order modes in the mid-infrared spectrum of C{sub 60}, and propose that neutral C{sub 60} is the carrier of the unidentified emission band at 6.49 μ m which has been observed in fullerene-rich environments.

Important plasma problems in astrophysics

International Nuclear Information System (INIS)

Kulsrud, R.M.

1995-01-01

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

Relativistic astrophysics

CERN Document Server

Demianski, Marek

2013-01-01

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

Relativistic astrophysics and theory of gravity

International Nuclear Information System (INIS)

Zel'dovich, Ya.B.

1982-01-01

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

Trojan horse particle invariance: The impact on nuclear astrophysics

International Nuclear Information System (INIS)

Pizzone, R. G.; La Cognata, M.; Spitaleri, C.; Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Lamia, L.; Spartá, R.; Tumino, A.

2014-01-01

In the current picture of nuclear astrophysics indirect methods and, in particular, the Trojan Horse Method cover a crucial role for the measurement of charged particle induced reactions cross sections of astrophysical interest, in the energy range required by the astrophysical scenarios. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The key to the method is the quasi-free break-up and some of its properties will be investigated in the present work. In particular, the Trojan Horse nucleus invariance will be studied and previous studies will be extended to the cases of the binary d(d, p)t and 6 Li(d,α) 4 He reactions, which were tested using different quasi-free break-up's, namely 6 Li and 3 He. The astrophysical S(E)-factor were then extracted with the Trojan Horse formalism applied to the two different break-up schemes and compared with direct data as well as with previous indirect investigations. The very good agreement confirms the independence of binary indirect cross section on the chosen spectator particle also for these reactions

Trojan horse particle invariance: The impact on nuclear astrophysics

Energy Technology Data Exchange (ETDEWEB)

Pizzone, R. G.; La Cognata, M. [Laboratori Nazionali del Sud - INFN, Catania (Italy); Spitaleri, C. [Universitá di Catania and Laboratori Nazionali del Sud - INFN (Italy); Bertulani, C. A. [Texas A and M University, Commerce (United States); Mukhamedzhanov, A. M. [Texas A and M University, College Station, Texas (United States); Blokhintsev, L. D. [Moscow State University, Moscow (Russian Federation); Lamia, L.; Spartá, R. [Universitá di Catania and Laboratori Nazionali del Sud - INFN, Catania (Italy); Tumino, A. [Universitá Kore, Enna (Italy)

2014-05-02

In the current picture of nuclear astrophysics indirect methods and, in particular, the Trojan Horse Method cover a crucial role for the measurement of charged particle induced reactions cross sections of astrophysical interest, in the energy range required by the astrophysical scenarios. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The key to the method is the quasi-free break-up and some of its properties will be investigated in the present work. In particular, the Trojan Horse nucleus invariance will be studied and previous studies will be extended to the cases of the binary d(d, p)t and {sup 6}Li(d,α){sup 4}He reactions, which were tested using different quasi-free break-up's, namely {sup 6}Li and {sup 3}He. The astrophysical S(E)-factor were then extracted with the Trojan Horse formalism applied to the two different break-up schemes and compared with direct data as well as with previous indirect investigations. The very good agreement confirms the independence of binary indirect cross section on the chosen spectator particle also for these reactions.

Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics

Science.gov (United States)

Bemmerer, D.; Cowan, T. E.; Gohl, S.; Ilgner, C.; Junghans, A. R.; Reinhardt, T. P.; Rimarzig, B.; Reinicke, S.; Röder, M.; Schmidt, K.; Schwengner, R.; Stöckel, K.; Szücs, T.; Takács, M.; Wagner, A.; Wagner, L.; Zuber, K.

2015-05-01

Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, proteced from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise has been carried out using the same HPGe detector in a typical nuclear astrophysics setup at several sites, including the Dresden Felsenkeller underground laboratory. It was found that its rock overburden of 45m rock, together with an active veto against the remaining muon flux, reduces the background to a level that is similar to the deep underground scenario. Based on this finding, a used 5 MV pelletron tandem with 250 μA upcharge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is underway. The project is now fully funded. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the planned access possibilities for external users will be reported.

Progress of Jinping Underground laboratory for Nuclear Astrophysics (JUNA

Directory of Open Access Journals (Sweden)

Liu WeiPing

2016-01-01

Full Text Available Jinping Underground lab for Nuclear Astrophysics (JUNA will take the advantage of the ultralow background in Jinping underground lab, high current accelerator based on an ECR source and highly sensitive detector to study directly a number of crucial reactions to the hydrostatic stellar evolution for the first time at their relevant stellar energies. In its first phase, JUNA aims at the direct measurements of 25Mg(p,γ26Al, 19F(p,α16O, 13C(α,n16O and 12C(α,γ16O. The experimental setup, which include the accelerator system with high stability and high intensity, the detector system, and the shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

The Trojan Horse method as an indirect approach for nuclear astrophysics studies

Energy Technology Data Exchange (ETDEWEB)

Tumino, A; Spitaleri, C; Cherubini, S; Cognata, M La; Lamia, L; Pizzone, R G; Puglia, S M R; Rapisarda, G G; Romano, S; Sergi, M L, E-mail: tumino@lns.infn.i [Laboratori Nazionali del Sud - INFN, Catania (Italy)

2010-01-01

The Trojan Horse method (THM) is a powerful indirect technique that provides a successful alternative path to determine the bare nucleus astrophysical S(E) factor for rearrangement reactions down to astrophysical energies. This is done by measuring the cross section for a suitable three body process in the quasi-free kinematics regime. Prescriptions and basic features will be presented together with some applications to demonstrate how THM works.

Astrophysics Decoding the cosmos

CERN Document Server

Irwin, Judith A

2007-01-01

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

[Experimental and theoretical high energy physics

International Nuclear Information System (INIS)

Boulware, D.

1988-01-01

We are carrying out a research program in high energy experimental particle physics. Studies of high energy hadronic interactions and leptoproduction processes continue using several experimental techniques. Progress has been made on the study of multiparticle production processes in nuclei. Ultra-high energy cosmic ray nucleus-nucleus interactions have been investigated by the Japanese American Cosmic Emulsion Experiment (JACEE) using balloon-borne emulsion chamber detectors. In the area of particle astrophysics, our studies of cosmic ray nuclear interactions have enabled us to make the world's most accurate determination of the composition of the cosmic rays above 10 13 eV. We have the only detector that can observe interaction vertices and identify particles at energies up to 10--15 eV. Our observations are getting close to placing limits on the acceleration mechanisms postulated for pulsars in which the spin and magnetic moment axes are at different angles. In June, 1989 approval was given by NASA for our participation in the Space Station program. The SCINATT experiment will make use of emulsion chamber detectors, similar to the planned JACEE hybrid balloon flight detectors. These detectors will permit precise determination of secondary particle charges, momenta and rapidities, and the accumulation of data will be at least a factor of 10 to 100 greater than in balloon experiments. Emulsion chamber techniques are also employed in an experiment using accelerator heavy ion beams at CERN and Brookhaven National Laboratory to investigate particle production processes in central collisions of nuclei in the energy range 15--200A GeV. Our study of hadroproduction in lepton interactions is continuing with approval of another 8 months run for deep inelastic muon scattering experiment E665 at Fermilab

Gravity, particles and astrophysics

International Nuclear Information System (INIS)

Wesson, P.S.

1980-01-01

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

Time-symmetric integration in astrophysics

Science.gov (United States)

Hernandez, David M.; Bertschinger, Edmund

2018-04-01

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

Astrophysical Concepts

CERN Document Server

Harwit, Martin

2006-01-01

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

Applications for X-ray detectors in astrophysics

International Nuclear Information System (INIS)

Remillard, R.A.

2003-01-01

Full text: Position-sensitive X-Ray detectors continue to playa central role in high-energy astrophysics. The current science goals are reviewed with emphasis on requirements in terms of camera performance. Wide-field imaging techniques, including coded mask cameras, are an essential part of space programs because of the transient nature of high-priority targets, e.g. eruptions from black-hole binaries and cosmic explosions such as gamma ray bursts. Pointing X-ray telescopes are being planned with a wide range of photon energies and with collection designs that include both mirrors and coded masks. Requirements for high spectral resolution and high time resolution are driven by diverse types of X-ray sources such as msec pulsars, quasars with emission-line profiles shaped by general relativity, and X-ray binaries that exhibit quasi-periodic oscillations in the range of 40-1300 Hz. Many laboratories and universities are involved in space-qualification of new detector technologies, e.g. CZT cameras, X-ray calorimeters, new types of CCDs, and GEM detectors. Even X-ray interferometry is on the horizon of NASA's science roadmap. The difficulties in advancing new technologies for space science applications require careful coordinations between industry and science groups in order to solve science problems while minimizing risk

Encyclopedia of Astronomy and Astrophysics

CERN Document Server

2002-01-01

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

Plasma in astrophysics

International Nuclear Information System (INIS)

Kulsrud, R.M.

1982-10-01

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

P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

Directory of Open Access Journals (Sweden)

S. Weber

2017-07-01

Full Text Available ELI-Beamlines (ELI-BL, one of the three pillars of the Extreme Light Infrastructure endeavour, will be in a unique position to perform research in high-energy-density-physics (HEDP, plasma physics and ultra-high intensity (UHI (>1022W/cm2 laser–plasma interaction. Recently the need for HED laboratory physics was identified and the P3 (plasma physics platform installation under construction in ELI-BL will be an answer. The ELI-BL 10 PW laser makes possible fundamental research topics from high-field physics to new extreme states of matter such as radiation-dominated ones, high-pressure quantum ones, warm dense matter (WDM and ultra-relativistic plasmas. HEDP is of fundamental importance for research in the field of laboratory astrophysics and inertial confinement fusion (ICF. Reaching such extreme states of matter now and in the future will depend on the use of plasma optics for amplifying and focusing laser pulses. This article will present the relevant technological infrastructure being built in ELI-BL for HEDP and UHI, and gives a brief overview of some research under way in the field of UHI, laboratory astrophysics, ICF, WDM, and plasma optics.

2006-2007 Academic training programme: QCD and high energy nuclear collision

CERN Multimedia

HR Department

2007-01-01

LECTURE SERIES 7, 8, 9 May QCD and high energy nuclear collisions D. Kharzeev, Brookhaven National Laboratory, USA 11:00 to 12:00 - Main Auditorium, Bldg. 500 on 7 and 8 May, Council Chamber on 9 May Six years ago, Relativistic Heavy Ion Collider at Brookhaven started colliding heavy nuclei at record center-of-mass energies of up to 200 GeV/nucleon. Very soon, the Large Hadron Collider at CERN will push the energy of the ions to an astounding 5 TeV/nucleon. What can be learnt from the experiments at these machines? What do we know about the physics of super--dense matter already? I will argue that heavy ion accelerators bring us to the new frontiers of physical knowledge by creating strong color fields and very high densities of partons, at which qualitatively new phenomena emerge. I will also discuss the cross-disciplinary implications for cosmology, astrophysics, and connections to condensed matter physics.

2006-2007 Academic training programme: QCD and high energy nuclear collisions

CERN Multimedia

HR Department

2007-01-01

LECTURE SERIES 7, 8, 9 May 2007 11:00 to 12:00 - Main Auditorium, Bldg. 500 on 7 and 8 May, Council Chamber on 9 May QCD and high energy nuclear collisions D. Kharzeev, Brookhaven National Laboratory, USA Six years ago, the Relativistic Heavy Ion Collider at Brookhaven started colliding heavy nuclei at record center-of-mass energies of up to 200 GeV/nucleon. Very soon, the Large Hadron Collider at CERN will push the energy of the ions to an astounding 5 TeV/nucleon. What can be learnt from the experiments at these machines? What do we know about the physics of super--dense matter already? I will argue that heavy ion accelerators bring us to the new frontiers of physical knowledge by creating strong color fields and very high densities of partons, at which qualitatively new phenomena emerge. I will also discuss the cross-disciplinary implications for cosmology, astrophysics, and connections to condensed matter physics.

Astrophysics in a nutshell

CERN Document Server

Maoz, Dan

2007-01-01

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

A plasma deflagration accelerator as a platform for laboratory astrophysics

Science.gov (United States)

Underwood, Thomas C.; Loebner, Keith T. K.; Cappelli, Mark A.

2017-06-01

The replication of astrophysical flows in the laboratory is critical for isolating particular phenomena and dynamics that appear in complex, highly-coupled natural systems. In particular, plasma jets are observed in astrophysical contexts at a variety of scales, typically at high magnetic Reynolds number and driven by internal currents. In this paper, we present detailed measurements of the plasma parameters within deflagration-produced plasma jets, the scaling of these parameters against both machine operating conditions and the corresponding astrophysical phenomena. Using optical and spectroscopic diagnostics, including Schlieren cinematography, we demonstrate the production of current-driven plasma jets of ∼100 km/s and magnetic Reynolds numbers of ∼100, and discuss the dynamics of their acceleration into vacuum. The results of this study will contribute to the reproduction of various types of astrophysical jets in the laboratory and indicate the ability to further probe active research areas such as jet collimation, stability, and interaction.

Nuclear energy and astrophysics applications of ENDF/B-VII.1 evaluated nuclear library

International Nuclear Information System (INIS)

Pritychenko, B.

2012-01-01

Recently released ENDF/B-VII.1 evaluated nuclear library contains the most up-to-date evaluated neutron cross section and covariance data. These data provide new opportunities for nuclear science and astrophysics application development. The improvements in neutron cross section evaluations and more extensive utilization of covariance files, by the Cross Section Evaluation Working Group (CSEWG) collaboration, allowed users to produce neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates, and provide additional insights on the currently available neutron-induced reaction data. Nuclear reaction calculations using the ENDF/B-VII.1 library and current computer technologies will be discussed and new results will be presented

Support for the 38th International Conference on High Energy Physics, 3-10 August 2016

Energy Technology Data Exchange (ETDEWEB)

Kim, Young-Kee [Univ. of Chicago, IL (United States)

2017-06-19

The 38th International Conference on High Energy Physics (ICHEP) held in Chicago from August 3 to 10, 2016 was for physicists from around the world to gather to share the latest advancements in particle physics, astrophysics/cosmology, and accelerator science and to discuss plans for major future facilities. DOE funding provided partial support for space rental audio-visual services for scientific presentations at the conference.

Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

Science.gov (United States)

Chaplin, Vernon H; Bellan, Paul M

2015-07-01

An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

Astrophysical Institute, Potsdam

Science.gov (United States)

Murdin, P.

2000-11-01

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

Black hole astrophysics

International Nuclear Information System (INIS)

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

1979-01-01

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

Propagation of ultra-high-energy cosmic rays and their secondaries with CRPropa

International Nuclear Information System (INIS)

Vliet, Arjen Rene van

2015-04-01

Due to experiments like the Pierre Auger Observatory (Auger) and the Telescope Array (TA), high-statistics data is becoming available on the energy spectrum, the composition and the arrival directions of ultra-high-energy cosmic rays (UHECRs, cosmic rays with energies above ∝ 10 17 eV). To interpret this data in terms of actual astrophysical parameters, or to test astrophysical models against the measured data, dedicated simulations of the propagation of UHECRs from their sources to Earth are needed. To this end, the UHECR propagation code called CRPropa has been developed. It can take into account all relevant interactions with ambient photon backgrounds (pair production, photodisintegration and photopion production) as well as nuclear decay, cosmological evolution effects and deflections in extragalactic and galactic magnetic fields. CRPropa, including its newest features, is described in this thesis. When considering the propagation of ultra-high-energy nuclei, the dominant interaction for most isotopes and energies is photodisintegration. Photodisintegration has been implemented in CRPropa for all relevant isotopes (up to iron) and all relevant photodisintegration channels using cross-section calculations with the publicly-available code called TALYS, including extensions for the low mass numbers. This photodisintegration setup is compared here extensively with the photodisintegration scheme developed by Puget, Stecker and Bredekamp, leading to several improvements on the cross sections implemented in CRPropa. In the interactions of UHECRs with background photon fields, secondary neutrinos and photons, so-called cosmogenic neutrinos and photons, can be created. CRPropa can simulate the production and propagation of these secondary particles as well. The IceCube Neutrino Observatory (IceCube) has recently reported the first observation of extraterrestrial neutrinos in the PeV energy range. In this work is investigated whether these neutrinos could have

Plasma astrophysics

CERN Document Server

Kaplan, S A; ter Haar, D

2013-01-01

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

An invitation to astrophysics

CERN Document Server

Padmanabhan, Thanu

2006-01-01

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

Rounding Up the Astrophysical Weeds

Science.gov (United States)

McMillan, James P.

2016-09-01

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

VI School on Cosmic Rays and Astrophysics

International Nuclear Information System (INIS)

2017-01-01

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

Bibliometric indicators of young authors in astrophysics

DEFF Research Database (Denmark)

Havemann, Frank; Larsen, Birger

2015-01-01

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

Shukla-Spatschek diffusion effects on surface plasma waves in astrophysical turbulent plasmas

Science.gov (United States)

Lee, Myoung-Jae; Jung, Young-Dae

2017-02-01

The effects of Shukla-Spatschek turbulent diffusion on a temporal mode of surface waves propagating at the interface of an astrophysical turbulent plasma are investigated. The damping rates for high and low modes of surface wave are kinetically derived by employing the Vlasov-Poisson equation and the specular reflection boundary condition. We found that the diffusion caused by the fluctuating electric fields leads to damping for both high and low modes of surface waves. The high-mode damping is enhanced with an increase of the wavenumber and the diffusion coefficient, but suppressed by an increase of electron thermal energy. By contrast, the low-mode damping is suppressed as the wavenumber and the thermal energy increase although it is enhanced as the diffusion increases. The variation of the damping rate due to the Shukla-Spatschek turbulent diffusion is also discussed.

Dynamic high energy density plasma environments at the National Ignition Facility for nuclear science research

Science.gov (United States)

Cerjan, Ch J.; Bernstein, L.; Berzak Hopkins, L.; Bionta, R. M.; Bleuel, D. L.; Caggiano, J. A.; Cassata, W. S.; Brune, C. R.; Frenje, J.; Gatu-Johnson, M.; Gharibyan, N.; Grim, G.; Hagmann, Chr; Hamza, A.; Hatarik, R.; Hartouni, E. P.; Henry, E. A.; Herrmann, H.; Izumi, N.; Kalantar, D. H.; Khater, H. Y.; Kim, Y.; Kritcher, A.; Litvinov, Yu A.; Merrill, F.; Moody, K.; Neumayer, P.; Ratkiewicz, A.; Rinderknecht, H. G.; Sayre, D.; Shaughnessy, D.; Spears, B.; Stoeffl, W.; Tommasini, R.; Yeamans, Ch; Velsko, C.; Wiescher, M.; Couder, M.; Zylstra, A.; Schneider, D.

2018-03-01

The generation of dynamic high energy density plasmas in the pico- to nano-second time domain at high-energy laser facilities affords unprecedented nuclear science research possibilities. At the National Ignition Facility (NIF), the primary goal of inertial confinement fusion research has led to the synergistic development of a unique high brightness neutron source, sophisticated nuclear diagnostic instrumentation, and versatile experimental platforms. These novel experimental capabilities provide a new path to investigate nuclear processes and structural effects in the time, mass and energy density domains relevant to astrophysical phenomena in a unique terrestrial environment. Some immediate applications include neutron capture cross-section evaluation, fission fragment production, and ion energy loss measurement in electron-degenerate plasmas. More generally, the NIF conditions provide a singular environment to investigate the interplay of atomic and nuclear processes such as plasma screening effects upon thermonuclear reactivity. Achieving enhanced understanding of many of these effects will also significantly advance fusion energy research and challenge existing theoretical models.

Concurrent Application of ANC and THM to assess the 13C(α, n)16O Absolute Cross Section at Astrophysical Energies and Possible Consequences for Neutron Production in Low-mass AGB Stars

Science.gov (United States)

Trippella, O.; La Cognata, M.

2017-03-01

The {}13{{C}}{(α ,n)}16{{O}} reaction is considered to be the main neutron source responsible for the production of heavy nuclides (from {Sr} to {Bi}) through slow n-capture nucleosynthesis (s-process) at low temperatures during the asymptotic giant branch phase of low-mass stars (≲ 3{--}4 {M}⊙ , or LMSs). In recent years, several direct and indirect measurements have been carried out to determine the cross section at the energies of astrophysical interest (around 190+/- 40 {keV}). However, they yield inconsistent results that cause a highly uncertain reaction rate and affect the neutron release in LMSs. In this work we have combined two indirect approaches, the asymptotic normalization coefficient and the Trojan horse method, to unambiguously determine the absolute value of the {}13{{C}}{(α ,n)}16{{O}} astrophysical factor. With these, we have determined a very accurate reaction rate to be introduced into astrophysical models of s-process nucleosynthesis in LMSs. Calculations using this recommended rate have shown limited variations in the production of those neutron-rich nuclei (with 86≤slant A≤slant 209) that receive contribution only by slow neutron captures.

Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

International Nuclear Information System (INIS)

Smith, M.S.

1994-01-01

The potential for understanding spectacular stellar explosions such as novae, supernovae, and X-ray bursts will be greatly enhanced by the availability of the low-energy, high-intensity, accelerated beams of proton-rich radioactive nuclei currently being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. These beams will be utilized in absolute cross section measurements of crucial (p, γ) capture reactions in efforts to resolve the substantial qualitative uncertainties in current models of explosive stellar hydrogen burning outbursts. Details of the nuclear astrophysics research program with the unique HRIBF radioactive beams and a dedicated experimental endstation--centered on the Daresbury Recoil Separator--will be presented

Monopole, astrophysics and cosmic ray observatory at Gran Sasso

International Nuclear Information System (INIS)

Demarzo, C.; Enriquez, O.; Giglietto, N.

1985-01-01

A new large area detector, MACRO was approved for installation at the Gran Sasso Laboratory in Italy. The detector will be dedicated to the study of naturally penetrating radiation deep underground. It is designed with the general philosophy of covering the largest possible area with a detector having both sufficient built-in redundancy and use of complementary techniques to study very rare phenomena. The detector capabilities will include monopole investigations significantly below the Parker bound; astrophysics studies of very high energy gamma ray and neutrino point sources; cosmic ray measurements of single and multimuons; and the general observation of rare new forms of matter in the cosmic rays

Monopole, astrophysics and cosmic ray observatory at Gran Sasso

Science.gov (United States)

Demarzo, C.; Enriquez, O.; Giglietto, N.; Posa, F.; Attolini, M.; Baldetti, F.; Giacomelli, G.; Grianti, F.; Margiotta, A.; Serra, P.

1985-01-01

A new large area detector, MACRO was approved for installation at the Gran Sasso Laboratory in Italy. The detector will be dedicated to the study of naturally penetrating radiation deep underground. It is designed with the general philosophy of covering the largest possible area with a detector having both sufficient built-in redundancy and use of complementary techniques to study very rare phenomena. The detector capabilities will include monopole investigations significantly below the Parker bound; astrophysics studies of very high energy gamma ray and neutrino point sources; cosmic ray measurements of single and multimuons; and the general observation of rare new forms of matter in the cosmic rays.

Minicourses in Astrophysics, Modular Approach, Vol. I.

Science.gov (United States)

Illinois Univ., Chicago.

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

Neutrino astrophysics

International Nuclear Information System (INIS)

Roulet, E.

2001-01-01

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

AN UPDATED {sup 6}Li(p, {alpha}){sup 3}He REACTION RATE AT ASTROPHYSICAL ENERGIES WITH THE TROJAN HORSE METHOD

Energy Technology Data Exchange (ETDEWEB)

Lamia, L.; Spitaleri, C.; Sergi, M. L. [Dipartimento di Fisica e Astronomia, Universita di Catania, I-95123 Catania (Italy); Pizzone, R. G.; Tumino, A.; La Cognata, M. [INFN-Laboratori Nazionali del Sud, I-95125 Catania (Italy); Tognelli, E.; Degl' Innocenti, S.; Prada Moroni, P. G. [Dipartimento di Fisica, Universita di Pisa, I-56127 Pisa (Italy); Pappalardo, L. [Dipartimento di Fisica e Scienze della Terra, Universita di Ferrara, I-44100 Ferrara (Italy)

2013-05-01

The lithium problem influencing primordial and stellar nucleosynthesis is one of the most interesting unsolved issues in astrophysics. {sup 6}Li is the most fragile of lithium's stable isotopes and is largely destroyed in most stars during the pre-main-sequence (PMS) phase. For these stars, the convective envelope easily reaches, at least at its bottom, the relatively low {sup 6}Li ignition temperature. Thus, gaining an understanding of {sup 6}Li depletion also gives hints about the extent of convective regions. For this reason, charged-particle-induced reactions in lithium have been the subject of several studies. Low-energy extrapolations of these studies provide information about both the zero-energy astrophysical S(E) factor and the electron screening potential, U{sub e} . Thanks to recent direct measurements, new estimates of the {sup 6}Li(p, {alpha}){sup 3}He bare-nucleus S(E) factor and the corresponding U{sub e} value have been obtained by applying the Trojan Horse method to the {sup 2}H({sup 6}Li, {alpha} {sup 3}He)n reaction in quasi-free kinematics. The calculated reaction rate covers the temperature window 0.01 to 2T{sub 9} and its impact on the surface lithium depletion in PMS models with different masses and metallicities has been evaluated in detail by adopting an updated version of the FRANEC evolutionary code.

The fundamentals of stellar astrophysics

International Nuclear Information System (INIS)

Collins, G.W. II.

1989-01-01

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

Nuclear astrophysics with indirect methods

International Nuclear Information System (INIS)

Shubhchintak

2016-01-01

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

Astrophysical cosmology

Science.gov (United States)

Bardeen, J. M.

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

Astrophysical cosmology

International Nuclear Information System (INIS)

Bardeen, J.M.

1986-01-01

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

Remarks about the thermodynamics of astrophysical systems in mutual interaction and related notions

International Nuclear Information System (INIS)

Velazquez, L

2016-01-01

ensembles in this scenario. To clarify how some of conventional notions and theoretical frameworks could be extended to open astrophysical systems, an exploratory study of a paradigmatic situation is presented: a binary astrophysical system. This analysis is carried out in the framework of the quadrupole approximation, which represents the lowest coupling among internal and collective degrees of freedom. Apparently, collective motions are responsible for a non-linear energy interchange among the astrophysical systems. This mechanism introduces some modifications in stationary and stability conditions for the thermodynamic equilibrium such as a generalization of Thirring’s stability condition for systems with negative heat capacities (1970 Z. Phys. 235 339). Additionally, the stability of collective motions of this binary astrophysical system is also discussed, which is related to the low energy thermodynamic behavior of the model discussed by Votyakov and colleagues (2002 Phys. Rev. Lett. 89 031101). The thermodynamic limit for self-gravitating gas of identical non-relativistic point particles is then derived and compared with other different proposals. The astrophysical counterpart of the Gibbs–Duhem relation is obtained and compared with the recent proposal of Latella and colleagues (2015 Phys. Rev. Lett. 114 230601). Finally, the incidence of non-extensivity during the merger of two identical astrophysical systems is analyzed. Contrary to the situation considered in the Gibbs paradox, the merger is an irreversible process that crucially depends on the existence (or non-existence) of the external gravitational influence of other systems. (paper: quantum statistical physics, condensed matter, integrable systems)

Distance correlation methods for discovering associations in large astrophysical databases

International Nuclear Information System (INIS)

Martínez-Gómez, Elizabeth; Richards, Mercedes T.; Richards, Donald St. P.

2014-01-01

High-dimensional, large-sample astrophysical databases of galaxy clusters, such as the Chandra Deep Field South COMBO-17 database, provide measurements on many variables for thousands of galaxies and a range of redshifts. Current understanding of galaxy formation and evolution rests sensitively on relationships between different astrophysical variables; hence an ability to detect and verify associations or correlations between variables is important in astrophysical research. In this paper, we apply a recently defined statistical measure called the distance correlation coefficient, which can be used to identify new associations and correlations between astrophysical variables. The distance correlation coefficient applies to variables of any dimension, can be used to determine smaller sets of variables that provide equivalent astrophysical information, is zero only when variables are independent, and is capable of detecting nonlinear associations that are undetectable by the classical Pearson correlation coefficient. Hence, the distance correlation coefficient provides more information than the Pearson coefficient. We analyze numerous pairs of variables in the COMBO-17 database with the distance correlation method and with the maximal information coefficient. We show that the Pearson coefficient can be estimated with higher accuracy from the corresponding distance correlation coefficient than from the maximal information coefficient. For given values of the Pearson coefficient, the distance correlation method has a greater ability than the maximal information coefficient to resolve astrophysical data into highly concentrated horseshoe- or V-shapes, which enhances classification and pattern identification. These results are observed over a range of redshifts beyond the local universe and for galaxies from elliptical to spiral.

Astrophysics and particle physics in space with the Alpha Magnetic Spectrometer

CERN Document Server

Lamanna, G

2003-01-01

The Alpha Magnetic Spectrometer is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (>1 GeV) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic- ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the antimatter and the dark matter searches. (53 refs).

Astrophysics on the Lab Bench

Science.gov (United States)

Hughes, Stephen W.

2010-01-01

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

Origin of the High-energy Neutrino Flux at IceCube

Science.gov (United States)

Carceller, J. M.; Illana, J. I.; Masip, M.; Meloni, D.

2018-01-01

We discuss the spectrum of the different components in the astrophysical neutrino flux reaching the Earth, and the possible contribution of each component to the high-energy IceCube data. We show that the diffuse flux from cosmic ray (CR) interactions with gas in our galaxy implies just two events among the 54-event sample. We argue that the neutrino flux from CR interactions in the intergalactic (intracluster) space depends critically on the transport parameter δ describing the energy dependence in the diffusion coefficient of galactic CRs. Our analysis motivates a {E}-2.1 neutrino spectrum with a drop at PeV energies that fits the data well, including the non-observation of the Glashow resonance at 6.3 PeV. We also show that a CR flux described by an unbroken power law may produce a neutrino flux with interesting spectral features (bumps and breaks) related to changes in the CR composition.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 29; Issue 1-2. Energy Dependence of Near-relativistic Electron Spectrum at Geostationary Orbit during the SEP Events of 2005. A. Chandrasekhar Reddy Jatin Rathod Girija Rajaram Radharani Alyana D. S. Misra C. G. Patil M. Y. S. Prasad ...

astrophysical significance

Directory of Open Access Journals (Sweden)

Dartois E.

2014-02-01

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

Scaling laws in high-energy inverse compton scattering. II. Effect of bulk motions

International Nuclear Information System (INIS)

Nozawa, Satoshi; Kohyama, Yasuharu; Itoh, Naoki

2010-01-01

We study the inverse Compton scattering of the CMB photons off high-energy nonthermal electrons. We extend the formalism obtained by the previous paper to the case where the electrons have nonzero bulk motions with respect to the CMB frame. Assuming the power-law electron distribution, we find the same scaling law for the probability distribution function P 1,K (s) as P 1 (s) which corresponds to the zero bulk motions, where the peak height and peak position depend only on the power-index parameter. We solved the rate equation analytically. It is found that the spectral intensity function also has the same scaling law. The effect of the bulk motions to the spectral intensity function is found to be small. The present study will be applicable to the analysis of the x-ray and gamma-ray emission models from various astrophysical objects with nonzero bulk motions such as radio galaxies and astrophysical jets.

Space astronomy and astrophysics program by NASA

Science.gov (United States)

Hertz, Paul L.

2014-07-01

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

New Improved Indirect Measurement of the F-19(p, alpha)O-16 Reaction at Energies of Astrophysical Relevance

Czech Academy of Sciences Publication Activity Database

Indelicato, I.; La Cognata, M.; Spitaleri, C.; Burjan, Václav; Cherubini, S.; Gulino, M.; Hayakawa, S.; Hons, Zdeněk; Kroha, Václav; Lamia, L.; Mazzocco, M.; Mrázek, Jaromír; Pizzone, R. G.; Romano, S.; Strano, E.; Torresi, D.; Tumino, A.

2017-01-01

Roč. 845, č. 1 (2017), č. článku 19. ISSN 0004-637X Institutional support: RVO:61389005 Keywords : nuclear reactions * nucleosynthesis * abundances Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

Measurements of the Coulomb dissociation cross section of 156 MeV 6Li projectiles at extremely low relative fragment energies of astrophysical interest

International Nuclear Information System (INIS)

Kiener, J.; Gils, H.J.; Rebel, H.; Zagromski, S.; Gsottschneider, G.; Heide, N.; Jelitto, H.; Wentz, J.; Baur, G.

1991-04-01

Coulomb dissociation of light nuclear projectiles in the electric field of heavy target nuclei has been experimentally investigated as an alternative access to radiative capture cross sections at low relative energies of the fragments, which are of astrophysical interest. As a pilot experiment the breakup of 156 MeV 6 Li-projectiles at 208 Pb with small emission angles of the a particle and deuteron fragments has been studied. Both fragments were coincidentally detected in the focal plane of a magnetic spectrograph at several reaction angles well below the grazing angle and with relative angles between the fragments of 0deg-2deg. The experimental cross sections have been analyzed on the basis of the Coulomb breakup theory. The results for the resonant breakup give evidence for the strong dominance of the Coulomb dissociation mechanism and the absence of nuclear distortions, while the cross section for the nonresonant breakup follow theoretical predictions of the astrophysical S-factor and extrapolations of corresponding radiative capture reaction cross section to very low c. m. energies of the a particle and deuterons. Various implications of the approach are discussed. (orig.) [de

BigData as a Driver for Capacity Building in Astrophysics

Science.gov (United States)

Shastri, Prajval

2015-08-01

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

Collision excitation studies useful for plasma diagnostics in astrophysics and fusion research

International Nuclear Information System (INIS)

Man Mohan; Aggarwal, Sunny

2015-01-01

The urgent research for energy sources has led many countries to collaborate on demonstrating the scientific and technological feasibility of magnetic fusion through the construction of International Thermonuclear Experimental Reactor in France. Data on highly charged ions with high Z will be important in this quest. Atomic data such as energy levels, radiative rates and collision excitation plays an important role in fusion research and extensive knowledge of atomic parameters is needed for plasma diagnostics. There is a very limited knowledge so far about the heavy atoms due to involvement of strong relativistic effects. For heavy atoms, electron correlation effects and relativistic effects are strongly coupled making it necessary to use a relativistic theory which also incorporates 'electron correlations effects on the same footing. For treating heavy atoms there have been new developments and many codes in the relativistic domain have been developed by various authors. Among them, multi-configuration Hartree (Dirac) Fock (MCDF) model based codes have been found very useful in ab-initio investigations. We have calculated the energy levels, radiative rates and lifetimes for heavy charged F, Na and Mg like tungsten ions using MCDF and FAC and compared our results with the other available theoretical and experimental results. Also, we have performed collision excitation calculations for F, Na and Mg like tungsten ions which will be useful for astrophysical and fusion, plasma. Also, we have compared our collision excitation results with distorted wave calculations and they are found to be in good agreement. The main goal of this paper is to provide useful atomic physics data for use in fusion research and in astrophysical and industrial plasmas. (author)

Interaction of low-energy highly charged ions with matter

International Nuclear Information System (INIS)

Ginzel, Rainer

2010-01-01

The thesis presented herein deals with experimental studies of the interaction between highly charged ions and neutral matter at low collision energies. The energy range investigated is of great interest for the understanding of both charge exchange reactions between ions comprising the solar wind and various astrophysical gases, as well as the creation of near-surface nanostructures. Over the course of this thesis an experimental setup was constructed, capable of reducing the kinetic energy of incoming ions by two orders of magnitude and finally focussing the decelerated ion beam onto a solid or gaseous target. A coincidence method was employed for the simultaneous detection of photons emitted during the charge exchange process together with the corresponding projectile ions. In this manner, it was possible to separate reaction channels, whose superposition presumably propagated large uncertainties and systematic errors in previous measurements. This work has unveiled unexpectedly strong contributions of slow radiative decay channels and clear evidence of previously only postulated decay processes in charge exchange-induced X-ray spectra. (orig.)

From dripline to dripline: Nuclear astrophysics in the laboratory

International Nuclear Information System (INIS)

Meisel, Zach

2016-01-01

For the better part of a century the field of nuclear astrophysics has aimed to answer fundamental questions about nature, such as the origin of the elements and the behavior of high-density, low-temperature matter. Sustained and concerted efforts in nuclear experiment have been key to achieving progress in these areas and will continue to be so. Here I will briefly review recent accomplishments and open questions in experimental nuclear astrophysics. (paper)

The role of Chandra in ten years from now and for the next few decades of astrophysical research

Science.gov (United States)

D'Abrusco, Raffaele; Becker, Glenn E.; McCollough, Michael L.; Rots, Arnold H.; Thong, Sinh A.; Van Stone, David; Winkelman, Sherry

2018-06-01

For almost twenty years, Chandra has advanced our understanding of the X-ray Universe by allowing astronomers to peer into a previously unexplored region of the high-energy observational parameters space. Thanks to its longevity,the mission has accumulated a large, unique body of observations whose legacy value, already tangible at this point, will only increase with time, and whose long-lasting influence extends well beyond the energy interval probed by Chandra. The Chandra archive, through the extensive characterization of the links between observations and literature, has measured the impact of Chandra on the astrophysical literature at a high level of granularity, providing striking evidence of how deeply and widely Chandra has impacted the advancement of both high-energy astrophysics and astronomical research from a multi-wavelength perspective. In this talk, based on the missions that have been submitted for recommendation at the next decadal survey and the possible outcomes of the evaluation process, I will discuss how Chandra archival data can be used to anticipate the projected scientific success and long-lasting effects of a X-ray mission like Lynx or, differently, how they will become instrumental to maximize the scientific output of a new generation of facilities that will observe in different energies. I will argue that, in either scenario, the centrality of Chandra will extend well after the final demise of the mission, and its data will continue serving the community in many different ways for the foreseeable future.

General Astrophysics with the HabEx Workhorse Camera

Science.gov (United States)

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

2018-01-01

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

Simulations of Laboratory Astrophysics Experiments using the CRASH code

Science.gov (United States)

Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

2015-11-01

Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

Plasma Photonic Devices for High Energy Density Science

International Nuclear Information System (INIS)

Kodama, R.

2005-01-01

High power laser technologies are opening a variety of attractive fields of science and technology using high energy density plasmas such as plasma physics, laboratory astrophysics, material science, nuclear science including medical applications and laser fusion. The critical issues in the applications are attributed to the control of intense light and enormous density of charged particles including efficient generation of the particles such as MeV electrons and protons with a current density of TA/cm2. Now these application possibilities are limited only by the laser technology. These applications have been limited in the control of the high power laser technologies and their optics. However, if we have another device consisted of the 4th material, i.e. plasma, we will obtain a higher energy density condition and explore the application possibilities, which could be called high energy plasma device. One of the most attractive devices has been demonstrated in the fast ignition scheme of the laser fusion, which is cone-guiding of ultra-intense laser light in to high density regions1. This is one of the applications of the plasma device to control the ultra-intense laser light. The other role of the devices consisted of transient plasmas is control of enormous energy-density particles in a fashion analogous to light control with a conventional optical device. A plasma fibre (5?m/1mm), as one example of the devices, has guided and deflected the high-density MeV electrons generated by ultra-intense laser light 2. The electrons have been well collimated with either a lens-like plasma device or a fibre-like plasma, resulting in isochoric heating and creation of ultra-high pressures such as Giga bar with an order of 100J. Plasmas would be uniquely a device to easily control the higher energy density particles like a conventional optical device as well as the ultra-intense laser light, which could be called plasma photonic device. (Author)

When neutrinos attack - the impact of agressive neutrinos in astrophysics.

Science.gov (United States)

Kneller, James

2004-11-01

Of all the constituents within the standard model of particle physics our understanding of the neutrino has benefited the most from the interaction of astrophysics and `terraphysics'. Much has been learned about the properties of the neutrino from each: experiments here on Earth temper our appreciation of the role that neutrinos play in the cosmos while astrophysics can provide the densities and temperatures in which the neutrinos do more than simply flee. But their reluctance to interact means that it is not until we venture into the most extreme environments of astrophysics that we observe neutrinos pushing back' as hard as they are being pushed'. We review two sites where this occurs: the early Universe and the accretion disk, engines' of gamma ray bursts. Neutrinos play an important role in the evolution of the early Universe with a particular focus upon the electron neutrino in determining the primordial elemental composition via its participation in the most important reaction at that time. Within gamma ray burst accretion disks we again see the electron neutrinos at work in the nuclear reactions and through their function as the coolant' for the disk. Removal of the disk energy, and its deposition into the remnants of the massive star surrounding the disk, may lead to the formation of highly relativistic jets that will later be observed as the burst. We show what has been learned so far about the neutrino and its properties from the study of such environments and discuss where future research is heading.

Progress report of a research program in experimental and theoretical high energy physics, 1 January 1992--31 May 1992

International Nuclear Information System (INIS)

Brandenberger, R.; Cutts, D.; Fried, H.M.; Guralnik, G.; Jevicki, A.; King, K.; Lanou, R.E.; Partridge, R.; Tan, C.I.; Widgoff, M.

1992-01-01

This report discusses research at Brown University in experimental and theoretical high energy physics. Some of the research programs conducted are: interactions of leptons and hadrons form accelerator and astrophysical sources; hadron interactions with hydrogen and heavier nuclei; large volume detector at the Gran Sasso Laboratory; GEM collaboration at SSC; and hadron colliders and neutrino physics

Penning-trap mass spectrometry of radioactive, highly charged ions. Measurements of neutron-rich Rb and Sr nuclides for nuclear astrophysics and development of a novel Penning trap for cooling highly charged ions

International Nuclear Information System (INIS)

Simon, Vanessa Veronique

2012-01-01

High-precision atomic mass measurements are vital for the description of nuclear structure, investigations of nuclear astrophysical processes, and tests of fundamental symmetries. The neutron-rich A ∼ 100 region presents challenges for modeling the astrophysical r-process because of sudden nuclear shape transitions. This thesis reports on high-precision masses of short-lived neutron-rich 94,97,98 Rb and 94,97-99 Sr isotopes using the TITAN Penning-trap mass spectrometer at TRIUMF. The isotopes were charge-bred to q = 15+; uncertainties of less than 4 keV were achieved. Results deviate by up to 11σ compared to earlier measurements and extend the region of nuclear deformation observed in the A∼100 region. A parameterized r-process model network calculation shows that mass uncertainties for the elemental abundances in this region are now negligible. Although beneficial for the measurement precision, the charge breeding process leads to an increased energy spread of the ions on the order of tens of eV/q. To eliminate this drawback, a Cooler Penning Trap (CPET) has been developed as part of this thesis. The novel multi-electrode trap structure of CPET forms nested potentials to cool HCI sympathetically using either electrons or protons to increase the overall efficiency and precision of the mass measurement. The status of the off-line setup and initial commissioning experiments are presented.

MHD instabilities in astrophysical plasmas: very different from MHD instabilities in tokamaks!

Science.gov (United States)

Goedbloed, J. P.

2018-01-01

The extensive studies of MHD instabilities in thermonuclear magnetic confinement experiments, in particular of the tokamak as the most promising candidate for a future energy producing machine, have led to an ‘intuitive’ description based on the energy principle that is very misleading for most astrophysical plasmas. The ‘intuitive’ picture almost directly singles out the dominant stabilizing field line bending energy of the Alfvén waves and, consequently, concentrates on expansion schemes that minimize that contribution. This happens when the wave vector {{k}}0 of the perturbations, on average, is perpendicular to the magnetic field {B}. Hence, all macroscopic instabilities of tokamaks (kinks, interchanges, ballooning modes, ELMs, neoclassical tearing modes, etc) are characterized by satisfying the condition {{k}}0 \\perp {B}, or nearly so. In contrast, some of the major macroscopic instabilities of astrophysical plasmas (the Parker instability and the magneto-rotational instability) occur when precisely the opposite condition is satisfied: {{k}}0 \\parallel {B}. How do those instabilities escape from the dominance of the stabilizing Alfvén wave? The answer to that question involves, foremost, the recognition that MHD spectral theory of waves and instabilities of laboratory plasmas could be developed to such great depth since those plasmas are assumed to be in static equilibrium. This assumption is invalid for astrophysical plasmas where rotational and gravitational accelerations produce equilibria that are at best stationary, and the associated spectral theory is widely, and incorrectly, believed to be non-self adjoint. These complications are addressed, and cured, in the theory of the Spectral Web, recently developed by the author. Using this method, an extensive survey of instabilities of astrophysical plasmas demonstrates how the Alfvén wave is pushed into insignificance under these conditions to give rise to a host of instabilities that do not

Cosmology and particle astrophysics. 2. ed.

International Nuclear Information System (INIS)

Bergstroem, L.; Goobar, A.

2006-01-01

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

Topics in High-Energy Astrophysics: X-ray Time Lags and Gamma-ray Flares

Science.gov (United States)

Kroon, John J.

2016-03-01

The Universe is host to a wide variety of high-energy processes that convert gravitational potential energy or rest-mass energy into non-thermal radiation such as bremsstrahlung and synchrotron. Prevailing models of X-ray emission from accreting Black Hole Binaries (BHBs) struggle to simultaneously fit the quiescent X-ray spectrum and the transients which result in the phenomenon known as X-ray time lags. And similarly, classical models of diffusive shock acceleration in pulsar wind nebulae fail to explain the extreme particle acceleration in very short timescales as is inferred from recent gamma-ray flares from the Crab nebula. In this dissertation, I develop new exact analytic models to shed light on these intriguing processes. I take a fresh look at the formation of X-ray time lags in compact sources using a new mathematical approach in which I obtain the exact Green's function solution. The resulting Green's function allows one to explore a variety of injection scenarios, including both monochromatic and broadband (bremsstrahlung) seed photon injection. I obtain the exact solution for the dependence of the time lags on the Fourier frequency, for both homogeneous and inhomogeneous clouds. The model can successfully reproduce both the observed time lags and the quiescent X-ray spectrum using a single set of coronal parameters. I show that the implied coronal radii in the new model are significantly smaller than those obtained in the Monte Carlo simulations, hence greatly reducing the coronal heating problem. Recent bright gamma-ray flares from the Crab nebula observed by AGILE and Fermi reaching GeV energies and lasting several days challenge the contemporary model for particle acceleration in pulsar wind nebulae, specifically the diffusive shock acceleration model. Simulations indicate electron/positron pairs in the Crab nebula pulsar wind must be accelerated up to PeV energies in the presence of ambient magnetic fields with strength B ~100 microG. No

The search for a main cause of uncertainty of the calculated astrophysical S factor for the direct radiative capture d(α, γ)6Li reaction at stellar energies

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Igamov, S.B.; Nishonov, M.M.; Yarmukhamedov, R.

2004-01-01

Full text: It is well known that the d( α,γ ) 6 Li reaction is one of the sources of the 6 Li production in the Big Bang nucleosynthesis. At the present time rather large uncertainties exist in the prediction of the rate of this reaction, which are mainly due to the absence both of the reliable experimental cross section (or the astrophysical S factor, S(E)) and of the theoretical calculations at extremely low energies E (E ≤ 600 keV) (see [1] and references therein). The aim of our work is to find out the principal cause of the existing large spread of the calculated values of S(E) at extremely low energies obtained by different authors, including the results of the present work. The basic idea of our consideration is that the d( α, γ) 6 Li reaction at such energies is predominantly peripheral [2]-[4]. Therefore the values of S(E) at extremely low energies are mainly determined by the nuclear vertex constant (NVC) (or by the asymptotic normalization constant (ANC)) for the virtual decay 6 Li→α+ d. Taking this circumstance into account, we calculated the NVC for the virtual decay 6 Li→α + d in the framework of three- body ( np) Faddeev equations in the momentum space. The Malfliet-Tjon and Graz potentials for NN interaction and the Sack-Biedenharn-Breit and Yamaguchi type potentials for αN interaction were used. The results of our calculations show that the obtained values of the NVC (or the ANC) are sensitive to the form of NN and αN potentials. This result is also corroborated by the values of the NVC calculated within the microscopic model using the Minnesota and Volkov potentials for NN- interaction [5]. The values of the NVC obtained in the present work were used to determine the values of the astrophysical S factor for the direct radiative capture d( α,γ ) 6 Li reaction at extremely low energies. It is shown that the values of the NVC corresponding to the different forms of NN and αN potentials lead to the different values of the

Carbon dioxide and climate: an astrophysical perspective

Energy Technology Data Exchange (ETDEWEB)

Kandel, R S

1979-01-01

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

Kinetic Modeling of Radiative Turbulence in Relativistic Astrophysical Plasmas: Particle Acceleration and High-Energy Flares

Science.gov (United States)

Wise, John

In the near future, next-generation telescopes, covering most of the electromagnetic spectrum, will provide a view into the very earliest stages of galaxy formation. To accurately interpret these future observations, accurate and high-resolution simulations of the first stars and galaxies are vital. This proposal is centered on the formation of the first galaxies in the Universe and their observational signatures in preparation for these future observatories. This proposal has two overall goals: 1. To simulate the formation and evolution of a statistically significant sample of galaxies during the first billion years of the Universe, including all relevant astrophysics while resolving individual molecular clouds, in various cosmological environments. These simulations will utilize a sophisticated physical model of star and black hole formation and feedback, including radiation transport and magnetic fields, which will lead to the most realistic and resolved predictions for the early universe; 2. To predict the observational features of the first galaxies throughout the electromagnetic spectrum, allowing for optimal extraction of galaxy and dark matter halo properties from their photometry, imaging, and spectra; The proposed research plan addresses a timely and relevant issue to theoretically prepare for the interpretation of future observations of the first galaxies in the Universe. A suite of adaptive mesh refinement simulations will be used to follow the formation and evolution of thousands of galaxies observable with the James Webb Space Telescope (JWST) that will be launched during the second year of this project. The simulations will have also tracked the formation and death of over 100,000 massive metal-free stars. Currently, there is a gap of two orders of magnitude in stellar mass between the smallest observed z > 6 galaxy and the largest simulated galaxy from "first principles", capturing its entire star formation history. This project will eliminate this

P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

Czech Academy of Sciences Publication Activity Database

Weber, Stefan A.; Bechet, Sabrina; Borneis, S.; Brabec, Lukáš; Bučka, Martin; Chacon-Golcher, Edwin; Ciappina, Marcelo F.; De Marco, Massimo; Fajstavr, Antonín; Falk, Kateřina; Garcia, E.-R.; Grosz, Jakub; Gu, Yanjun; Hernandez Martin, Juan C.; Holec, M.; Janečka, Pavel; Jantač, Martin; Jirka, Martin; Kadlecová, Hedvika; Khikhlukha, Danila; Klimo, Ondřej; Korn, Georg; Kramer, Daniel; Batheja, Deepak Kumar; Laštovička, Tomáš; Lutoslawski, P.; Morejon, L.; Olšovcová, Veronika; Rajdl, Marek; Renner, Oldřich; Rus, Bedřich; Singh, Sushil K.; Šmíd, Michal; Sokol, Martin; Versaci, Roberto; Vrána, Roman; Vranic, M.; Vyskočil, Jiří; Wolf, Adam; Yu, Q.

2017-01-01

Roč. 2, č. 4 (2017), s. 149-176 E-ISSN 2468-080X R&D Projects: GA MŠk LQ1606; GA MŠk LM2015065; GA MŠk EF15_008/0000162; GA MŠk EF15_003/0000449 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162; OP VVV - HiFi(XE) CZ.02.1.01/0.0/0.0/15_003/0000449 Institutional support: RVO:68378271 Keywords : high-energy-density- physics * ultra-high-intensity * warm dense matter * laboratory astrophysics * high repetition rate lasers * plasma optics * inertial confinement fusion Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics )

Follow-up of high energy neutrinos detected by the ANTARES telescope

Science.gov (United States)

Mathieu, Aurore

2016-04-01

The ANTARES telescope is well-suited to detect high energy neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky with a high duty cycle. Potential neutrino sources are gamma-ray bursts, core-collapse supernovae and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a detection method based on follow-up observations from the neutrino direction has been developed. This program, denoted as TAToO, includes a network of robotic optical telescopes (TAROT, Zadko and MASTER) and the Swift-XRT telescope, which are triggered when an "interesting" neutrino is detected by ANTARES. A follow-up of special events, such as neutrino doublets in time/space coincidence or a single neutrino having a very high energy or in the specific direction of a local galaxy, significantly improves the perspective for the detection of transient sources. The analysis of early and long term follow-up observations to search for fast and slowly varying transient sources, respectively, has been performed and the results covering optical and X-ray data are presented in this contribution.

A Laboratory Astrophysical Jet to Study Canonical Flux Tubes

Energy Technology Data Exchange (ETDEWEB)

You, Setthivoine [Univ. of Washington, Seattle, WA (United States)

2017-12-20

Understanding the interaction between plasma flows and magnetic fields remains a fundamental problem in plasma physics, with important applications to astrophysics, fusion energy, and advanced space propulsion. For example, flows are of primary importance in astrophysical jets even if it is not fully understood how jets become so long without becoming unstable. Theories for the origin of magnetic fields in the cosmos rely on flowing charged fluids that should generate magnetic fields, yet this remains to be demonstrated experimentally. Fusion energy reactors can be made smaller with flows that improve stability and confinement. Advanced space propulsion could be more efficient with collimated and stable plasma flows through magnetic nozzles but must eventually detach from the nozzle. In all these cases, there appears to be a spontaneous emergence of flowing and/or magnetic structures, suggesting a form of self-organization in plasmas. Beyond satisfying simple intellectual curiosity, understanding plasma self-organization could enable the development of methods to control plasma structures for fusion energy, space propulsion, and other applications. The research project has therefore built a theory and an experiment to investigate the interaction between magnetic fields and plasma flows. The theory is called canonical field theory for short, and the experiment is called Mochi after a rice cake filled with surprising, yet delicious fillings.

Characterizing the astrophysical S factor for 12C+12C fusion with wave-packet dynamics

Science.gov (United States)

Diaz-Torres, Alexis; Wiescher, Michael

2018-05-01

A quantitative study of the astrophysically important subbarrier fusion of 12C+12C is presented. Low-energy collisions are described in the body-fixed reference frame using wave-packet dynamics within a nuclear molecular picture. A collective Hamiltonian drives the time propagation of the wave packet through the collective potential-energy landscape. The fusion imaginary potential for specific dinuclear configurations is crucial for understanding the appearance of resonances in the fusion cross section. The theoretical subbarrier fusion cross sections explain some observed resonant structures in the astrophysical S factor. These cross sections monotonically decline towards stellar energies. The structures in the data that are not explained are possibly due to cluster effects in the nuclear molecule, which need to be included in the present approach.

An introduction to observational astrophysics

CERN Document Server

Gallaway, Mark

2016-01-01

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

Nonlinear dynamics and astrophysics

International Nuclear Information System (INIS)

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

2000-01-01

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

PAMELA’S MEASUREMENTS OF MAGNETOSPHERIC EFFECTS ON HIGH-ENERGY SOLAR PARTICLES

Energy Technology Data Exchange (ETDEWEB)

Adriani, O.; Bongi, M. [Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples “Federico II,” I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991 Moscow (Russian Federation); Bellotti, R.; Bruno, A. [University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Bravar, U. [Space Science Center, University of New Hampshire, Durham, NH (United States); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Casolino, M.; De Donato, C. [INFN, Sezione di Rome “Tor Vergata,” I-00133 Rome (Italy); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); Christian, E. R.; Nolfo, G. A. de, E-mail: georgia.a.denolfo@nasa.gov [Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD (United States); and others

2015-03-01

The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections, is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument enables unique observations of SEPs including the composition and angular distribution of the particles about the magnetic field, i.e., pitch angle distribution, over a broad energy range (>80 MeV)—bridging a critical gap between space-based and ground-based measurements. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two distinct pitch angle distributions: a low-energy population that extends to 90° and a population that is beamed at high energies (>1 GeV), consistent with neutron monitor measurements. To explain a low-energy SEP population that exhibits significant scattering or redistribution accompanied by a high-energy population that reaches the Earth relatively unaffected by dispersive transport effects, we postulate that the scattering or redistribution takes place locally. We believe that these are the first comprehensive measurements of the effects of solar energetic particle transport in the Earth’s magnetosheath.

Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

International Nuclear Information System (INIS)

Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

2010-01-01

The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the 18 F+p→ 15 O+α process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

Goddard's Astrophysics Science Division Annual Report 2013

Science.gov (United States)

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

2014-01-01

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

H- photodetachment and radiative attachment for astrophysical applications

Science.gov (United States)

McLaughlin, B. M.; Stancil, P. C.; Sadeghpour, H. R.; Forrey, R. C.

2017-06-01

We combine R-matrix calculations, asymptotic relations, and comparison to available experimental data to construct an H- photodetachment cross section reliable over a large range of photon energies and take into account the series of auto-detaching shape and Feshbach resonances between 10.92 and 14.35 eV. The accuracy of the cross section is controlled by ensuring that it satisfies all known oscillator strength sum rules, including contributions from the resonances and single-photon double-electron photodetachment. From the resulting recommended cross section, spontaneous and stimulated radiative attachment rate coefficients are obtained. Photodetachment rates are also computed for the standard interstellar radiation field, in diffuse and dense interstellar clouds, for blackbody radiation, and for high redshift distortion photons in the recombination epoch. Implications are investigated for these astrophysical radiation fields and epochs.

Nuclear reactions in astrophysics

International Nuclear Information System (INIS)

Arnould, M.; Rayet, M.

1990-01-01

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

Production of radiatively cooled hypersonic plasma jets and links to astrophysical jets

International Nuclear Information System (INIS)

Lebedev, S V; Ciardi, A; Ampleford, D J; Bland, S N; Bott, S C; Chittenden, J P; Hall, G N; Rapley, J; Jennings, C; Sherlock, M; Frank, A; Blackman, E G

2005-01-01

We present results of high energy density laboratory experiments on the production of supersonic radiatively cooled plasma jets with dimensionless parameters (Mach number ∼30, cooling parameter ∼1 and density contrast ρ j /ρ a ∼ 10) similar to those in young stellar objects jets. The jets are produced using two modifications of wire array Z-pinch driven by 1 MA, 250 ns current pulse of MAGPIE facility at Imperial College, London. In the first set of experiments the produced jets are purely hydrodynamic and are used to study deflection of the jets by the plasma cross-wind, including the structure of internal oblique shocks in the jets. In the second configuration the jets are driven by the pressure of the toroidal magnetic field and this configuration is relevant to the astrophysical models of jet launching mechanisms. Modifications of the experimental configuration allowing the addition of the poloidal magnetic field and angular momentum to the jets are also discussed. We also present three-dimensional resistive magneto-hydrodynamic simulations of the experiments and discuss the scaling of the experiments to the astrophysical systems

A combined cosmic ray muon spectrometer and high energy air shower array

International Nuclear Information System (INIS)

Cherry, M.L.; Ayres, D.S.; Halzen, F.

1986-01-01

Cosmic rays have been detected at energies in excess of 10 20 eV, and individual sources have been conclusively identified as intense emitters of gamma rays at energies up to 10 16 eV. There is clearly a great deal of exciting astrophysics to be learned from such studies, but it has been suggested that there may be particle physics to be learned from the cosmic beam as well. Based in particular on the reports of surprisingly high fluxes of underground muons from the direction of Cygnus X-3 modulated by the known orbital period, there have been several suggestions recently invoking stable supersymmetric particles produced at Cygnus X-3, enhanced muon production from high energy photons, quark matter, and ''cygnets.'' Although the underground muon results have been questioned, it may still be worthwhile to consider the possibility of new physics beyond the standard model with energy scale (G/sub F/)/sup -1/2/ ≥ 0.25 TeV. For example, there have been recent discussions on the experimental signatures to be observed from new high energy photon couplings to matter, exchanges between constituent quarks and leptons, and stable gluinos and photinos mixed in with the cosmic gamma ray flux. We describe here a possible detector to search for such effects. We utilize the possibility that point sources like Cygnus X-3 can be used to provide a directional time-modulated ''tagged'' high energy photon beam

Nuclear reactions in AGB nucleosynthesis: the 19F(α, p22Ne at energies of astrophysical relevance

Directory of Open Access Journals (Sweden)

D’Agata G.

2017-01-01

Full Text Available The abundance of 19F in the universe is strictly related to standard and extra-mixing processes taking place inside AGB-stars, that are considered to be the most important sites for its production. Nevertheless the way in which it is destroyed is far from being well understood. For this reason we studied the 19F(α,p22Ne reaction, that is supposed to be the main destruction channel in the Helium-rich part of the star. In this experiment, the reaction has been studied in the energy range of relevance for astrophysics (0÷1 MeV via the Trojan Horse Method (THM, using the three-body reaction 6Li(19F,p22Ned.

Cyberinfrastructure for Computational Relativistic Astrophysics

OpenAIRE

Ott, Christian

2012-01-01

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

Astrophysical neutrinos flavored with beyond the Standard Model physics

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Rasmus W.; Ackermann, Markus; Winter, Walter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Lechner, Lukas [Vienna Univ. of Technology (Austria). Dept. of Physics; Kowalski, Marek [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik

2017-07-15

We systematically study the allowed parameter space for the flavor composition of astrophysical neutrinos measured at Earth, including beyond the Standard Model theories at production, during propagation, and at detection. One motivation is to illustrate the discrimination power of the next-generation neutrino telescopes such as IceCube-Gen2. We identify several examples that lead to potential deviations from the standard neutrino mixing expectation such as significant sterile neutrino production at the source, effective operators modifying the neutrino propagation at high energies, dark matter interactions in neutrino propagation, or non-standard interactions in Earth matter. IceCube-Gen2 can exclude about 90% of the allowed parameter space in these cases, and hence will allow to efficiently test and discriminate models. More detailed information can be obtained from additional observables such as the energy-dependence of the effect, fraction of electron antineutrinos at the Glashow resonance, or number of tau neutrino events.

Astrophysical neutrinos flavored with beyond the Standard Model physics

International Nuclear Information System (INIS)

Rasmussen, Rasmus W.; Ackermann, Markus; Winter, Walter; Lechner, Lukas; Kowalski, Marek; Humboldt-Universitaet, Berlin

2017-07-01

We systematically study the allowed parameter space for the flavor composition of astrophysical neutrinos measured at Earth, including beyond the Standard Model theories at production, during propagation, and at detection. One motivation is to illustrate the discrimination power of the next-generation neutrino telescopes such as IceCube-Gen2. We identify several examples that lead to potential deviations from the standard neutrino mixing expectation such as significant sterile neutrino production at the source, effective operators modifying the neutrino propagation at high energies, dark matter interactions in neutrino propagation, or non-standard interactions in Earth matter. IceCube-Gen2 can exclude about 90% of the allowed parameter space in these cases, and hence will allow to efficiently test and discriminate models. More detailed information can be obtained from additional observables such as the energy-dependence of the effect, fraction of electron antineutrinos at the Glashow resonance, or number of tau neutrino events.

Multi-TeV gamma ray and cosmic ray astrophysics with TAIGA

Energy Technology Data Exchange (ETDEWEB)

Tluczykont, Martin [Hamburg Univ. (Germany). Institut fuer Experimentalphysik; Collaboration: TAIGA Kollaboration

2016-07-01

The very high energy gamma-ray regime is the key to several questions in high energy astrophysics, the most prominent being the search for the origin of cosmic rays. Observations of gamma rays up to several 100 TeV are particularly important to spectrally resolve the cutoff regime of the long-sought Pevatrons, the accelerators of PeV cosmic rays. TAIGA is an international collaboration that has, in the past 3 years, installed the air Cherenkov timing array HiSCORE on an area of 0.25 square-km, and are currently installing a first 4m diameter imaging air Cherenkov telescope (IACT), to be operated in parallel with the timing array. Our aim is to combine the timing and imaging techniques on a large scale in order to optimize the air Cherenkov detection technique for energies above 10 TeV and up to several 100 TeV. Simulations show a clear potential of the planned hybrid event reconstruction, especially in the energy regime from 10 TeV to 100 TeV. The TAIGA experiment will be complemented by scintillator based particle detectors for a measurement of the muon content of the air shower at higher energies. The status of our experiment and the planned 1 square-km stage of TAIGA are discussed.

The importance of CNO isotopes in astrophysics

International Nuclear Information System (INIS)

Audoze, J.

1977-01-01

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

Recent progress in ab-initio studies of nuclear reactions of astrophysical interest with A ≤ 3

Science.gov (United States)

Marcucci, Laura E.

2018-03-01

We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the consequences for the solar neutrino fluxes of the recent determination for the astrophysical S-factor of the proton weak capture by proton, and on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis.

First Session of the Sant Cugat Forum on Astrophysics

CERN Document Server

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

2011-01-01

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

Transition-edge sensor arrays for UV-optical-IR astrophysics

International Nuclear Information System (INIS)

Burney, J.; Bay, T.J.; Barral, J.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Miller, A.J.; Nam, S.; Rosenberg, D.; Romani, R.W.; Tomada, A.

2006-01-01

Our research group has developed and characterized transition-edge sensor (TES) arrays for near IR-optical-near UV astrophysical observations. These detectors have a time-stamp accuracy of 0.3μs and an energy resolution of 0.16eV for 2.33eV photons at very high rates (30kHz). We have installed a 6x6 array of these TESs in an adiabatic demagnetization refrigerator equipped with windows for direct imaging. We discuss new instrumentation progress and current data in all aspects related to successful operation of this camera system, including: detector and array performance, position dependence and cross-talk, low-temperature and readout electronics, quantum and system efficiency, IR filtering, and focus and imaging

FOREWORD: Nuclear Physics in Astrophysics V

Science.gov (United States)

Auerbach, Naftali; Hass, Michael; Paul, Michael

2012-02-01

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

Astrophysical opacity library

International Nuclear Information System (INIS)

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

1977-08-01

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

Astrophysics Update 2

CERN Document Server

Mason, John W

2006-01-01

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

Numerical simulation in astrophysics

International Nuclear Information System (INIS)

Miyama, Shoken

1985-01-01

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

Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

Science.gov (United States)

Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.

2009-06-01

Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br

Directed Flow in Heavy-Ion Collisions and Its Implications for Astrophysics

Directory of Open Access Journals (Sweden)

Yuri B. Ivanov

2017-11-01

Full Text Available Analysis of directed flow ( v 1 of protons, antiprotons and pions in heavy-ion collisions is performed in the range of collision energies s N N = 2.7–39 GeV. Simulations have been done within a three-fluid model employing a purely hadronic equation of state (EoS and two versions of the EoS with deconfinement transitions: a first-order phase transition and a smooth crossover transition. The crossover EoS is unambiguously preferable for the description of experimental data at lower collision energies s N N ≲ 20 Gev. However, at higher collision energies s N N ≳ 20 Gev. the purely hadronic EoS again becomes advantageous. This indicates that the deconfinement EoS in the quark-gluon sector should be stiffer at high baryon densities than those used in the calculation. The latter finding is in agreement with that discussed in astrophysics in connection with existence of hybrid stars with masses up to about two solar masses.

Enhanced Starting Track Event Selection for Astrophysical Neutrinos in IceCube

Science.gov (United States)

Jero, Kyle; IceCube Collaboration

2017-09-01

IceCube’s measurements of the astrophysical neutrino flux have applied veto techniques to suppress atmospheric neutrinos and muons. All the vetos thus far have used the outer regions of the detector to identify and reject penetrating muon tracks, leaving the inner parts of the detector available to observe the astrophysical neutrino flux. Here we discuss a method that is optimized for muon neutrinos which have a charged-current interaction with a contained vertex. This analysis exploits the high quality directional information of muons to determine a veto on an event by event basis. The final sample will contain astrophysical neutrinos with good purity starting around 10 TeV.

Double layers and circuits in astrophysics

International Nuclear Information System (INIS)

Alfven, H.

1986-05-01

As the rate of energy release in a double layer with voltage DeltaV is P corresponding to IDeltaV, a double layer must be treated part of a circuit which delivers the current I. As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by menas of double layers. They must be replaced by particle models and circuit theory. A simple circuit is suggested which is applied to the energizing of auroroal particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the sun's axis which may give radiations detectable from earth. Double layers in space should be classified as a new type of celestial object (one example is the double radio sources). It is tentatively suggested in X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). A study of how a number of the most used textbooks in astrophysics treat important concepts like double layers, critical velocity, pinch effects and circuits is made. It is found that students using these textbooks remain essentially ignorant of even the existence of these, in spite of the fact that some of them have been well known for half a centry (e.g., double layers, Langmuir, 1929: pinch effect, Bennet, 1934). The conclusion is that astrophysics is too important to be left in the hands of the astrophysicist. Earth bound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory. At least by volume the universe consists to more than 99 percent of plasma, and electromagnetic forces are 10/sup39/ time stronger than gravitation

One-point fluctuation analysis of the high-energy neutrino sky

Energy Technology Data Exchange (ETDEWEB)

Feyereisen, Michael R.; Ando, Shin' ichiro [GRAPPA Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Tamborra, Irene, E-mail: m.r.feyereisen@uva.nl, E-mail: tamborra@nbi.ku.dk, E-mail: s.ando@uva.nl [Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen (Denmark)

2017-03-01

We perform the first one-point fluctuation analysis of the high-energy neutrino sky. This method reveals itself to be especially suited to contemporary neutrino data, as it allows to study the properties of the astrophysical components of the high-energy flux detected by the IceCube telescope, even with low statistics and in the absence of point source detection. Besides the veto-passing atmospheric foregrounds, we adopt a simple model of the high-energy neutrino background by assuming two main extra-galactic components: star-forming galaxies and blazars. By leveraging multi-wavelength data from Herschel and Fermi , we predict the spectral and anisotropic probability distributions for their expected neutrino counts in IceCube. We find that star-forming galaxies are likely to remain a diffuse background due to the poor angular resolution of IceCube, and we determine an upper limit on the number of shower events that can reasonably be associated to blazars. We also find that upper limits on the contribution of blazars to the measured flux are unfavourably affected by the skewness of the blazar flux distribution. One-point event clustering and likelihood analyses of the IceCube HESE data suggest that this method has the potential to dramatically improve over more conventional model-based analyses, especially for the next generation of neutrino telescopes.

Sunfall: a collaborative visual analytics system for astrophysics

Energy Technology Data Exchange (ETDEWEB)

Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

2008-07-07

Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

Sunfall: a collaborative visual analytics system for astrophysics

International Nuclear Information System (INIS)

Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C

2008-01-01

Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project

Sunfall: a collaborative visual analytics system for astrophysics

Energy Technology Data Exchange (ETDEWEB)

Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: CRAragon@lbl.gov

2008-07-15

Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

Computational Infrastructure for Nuclear Astrophysics

International Nuclear Information System (INIS)

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

2006-01-01

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

Modeling the astrophysical dynamical process with laser-plasmas

International Nuclear Information System (INIS)

Xia Jiangfan; Zhang Jun; Zhang Jie

2001-01-01

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

Providing theoretical data for detection of four formamidic acid isomers in astrophysical media

Science.gov (United States)

Vichietti, R. M.; da Silva, A. B. F.; Haiduke, R. L. A.

2018-03-01

We present a theoretical study, so that molecular data (geometrical parameters, vibrational frequencies, infrared intensities, electronic energies, enthalpies, and Gibbs energies) of four formamidic acid (FA) isomers (labeled here as FA1, FA2, FA3, and FA4) and formamide (HCONH2) are obtained from CCSD/cc-pVTZ, CCSD/aug-cc-pVTZ, CCSD/cc-pVQZ, and CCSD(T)/cc-pVTZ calculations. Furthermore, on the basis of insufficient or even lacking theoretical and experimental results in the literature, we employed the aforementioned theory levels to determine benchmark values of dipole moments and rotational constants for these four FA isomers in order to contribute for their detection in astrophysical environments. Besides, we provide for the first time data about forward and reverse rate constants (200-4000 K) and Arrhenius' parameters for each interconversion reaction between pairs of FA isomers as well as for the tautomeric process involving FA4 and formamide, which were calculated from a Complete Basis Set (CBS) extrapolation equation obtained at CCSD/cc-pVTZ optimized geometries. Our kinetic analysis indicated a faster interconversion between the FA structures in comparison with the FA4 ↔ HCONH2 process, suggesting that these isomers could co-exist in astrophysical media. Finally, we estimated that these isomers may be detected with relative abundances, [FAx]/[HCONH2] (x = 1, 2, 3, and 4), between ∼0.01 and ∼0.1% in astrophysical sources at chemical equilibrium conditions and temperatures around 1000 K. However, these ratios can become as high as ∼1, ∼3, and ∼5%, respectively, in hotter regions with temperatures around 2000, 3000, and 4000 K (expected, for example, in massive star-forming regions).

The Explorer program for astronomy and astrophysics

International Nuclear Information System (INIS)

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

1986-01-01

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

ASTROPHYSICS. Atom-interferometry constraints on dark energy.

Science.gov (United States)

Hamilton, P; Jaffe, M; Haslinger, P; Simmons, Q; Müller, H; Khoury, J

2015-08-21

If dark energy, which drives the accelerated expansion of the universe, consists of a light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity. Chameleon fields and other theories with screening mechanisms, however, can evade these tests by suppressing the forces in regions of high density, such as the laboratory. Using a cesium matter-wave interferometer near a spherical mass in an ultrahigh-vacuum chamber, we reduced the screening mechanism by probing the field with individual atoms rather than with bulk matter. We thereby constrained a wide class of dark energy theories, including a range of chameleon and other theories that reproduce the observed cosmic acceleration. Copyright © 2015, American Association for the Advancement of Science.

Highlights of the NASA particle astrophysics program

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

Highlights of the NASA particle astrophysics program

International Nuclear Information System (INIS)

Jones, William Vernon

2014-01-01

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

FIRST LIGHT: MeV ASTROPHYSICS FROM THE MOON

Energy Technology Data Exchange (ETDEWEB)

Miller, Richard S. [University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Lawrence, David J., E-mail: richard.s.miller@uah.edu [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

2016-06-01

We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5–9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4 σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

Direct measurement of resonance strengths in 34S(α ,γ )38Ar at astrophysically relevant energies using the DRAGON recoil separator

Science.gov (United States)

Connolly, D.; O'Malley, P. D.; Akers, C.; Chen, A. A.; Christian, G.; Davids, B.; Erikson, L.; Fallis, J.; Fulton, B. R.; Greife, U.; Hager, U.; Hutcheon, D. A.; Ilyushkin, S.; Laird, A. M.; Mahl, A.; Ruiz, C.

2018-03-01

Background: Nucleosynthesis of mid-mass elements is thought to occur under hot and explosive astrophysical conditions. Radiative α capture on 34S has been shown to impact nucleosynthesis in several such conditions, including core and shell oxygen burning, explosive oxygen burning, and type Ia supernovae. Purpose: Broad uncertainties exist in the literature for the strengths of three resonances within the astrophysically relevant energy range (ECM=1.94 -3.42 MeV at T =2.2 GK ). Further, there are several states in 38Ar within this energy range which have not been previously measured. This work aimed to remeasure the resonance strengths of states for which broad uncertainty existed as well as to measure the resonance strengths and energies of previously unmeasured states. Methods: Resonance strengths and energies of eight narrow resonances (five of which had not been previously studied) were measured in inverse kinematics with the DRAGON facility at TRIUMF by impinging an isotopically pure beam of 34S ions on a windowless 4He gas target. Prompt γ emissions of de-exciting 38Ar recoils were detected in an array of bismuth germanate scintillators in coincidence with recoil nuclei, which were separated from unreacted beam ions by an electromagnetic mass separator and detected by a time-of-flight system and a multianode ionization chamber. Results: The present measurements agree with previous results. Broad uncertainty in the resonance strength of the ECM=2709 keV resonance persists. Resonance strengths and energies were determined for five low-energy resonances which had not been studied previously, and their strengths were determined to be significantly weaker than those of previously measured resonances. Conclusions: The five previously unmeasured resonances were found not to contribute significantly to the total thermonuclear reaction rate. A median total thermonuclear reaction rate calculated using data from the present work along with existing literature values

Electric Currents along Astrophysical Jets

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Ioannis Contopoulos

2017-10-01

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

Experimental techniques for the detection of the high energy gamma rays of cosmic origin

International Nuclear Information System (INIS)

Dumitrescu, Gh.; Angelescu, T.; Radu, A.A.

2002-01-01

The observation of high energy gamma rays of cosmic origin in the early 90 by Volcano Ranch experiment opened a new direction of study in astrophysics. The very high energy and the very low flux of these gamma rays, posed numerous detection problems which in turn were the object of a very intense research activity. The present article tries to review the detection techniques for the high energy gamma rays of cosmic origin. In the 'Introduction' we summarize the specific problems involved in the detection of this type of radiation. 'Chapter 1' presents the classic technique based on the use of scintillation detectors. 'Chapter 2' includes the imaging atmospheric Cherenkov technique (IACT) and the sampling wavefront technique. 'Chapter 3' is dedicated to the detection of the atmospheric nitrogen. 'Chapter 4' describes issues related to the calibration of the detectors, the cross checking of the experimental data, the use of the Monte Carlo simulations and the use of the density observed at a distance of 600 m S(600), in order to estimate the primary energy. The characteristics of some future developments of the above presented techniques are included in the last chapter. (authors)

Astrophysics at RIA (ARIA) Working Group

International Nuclear Information System (INIS)

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

2006-01-01

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

Final Report for Research in High Energy Physics (University of Hawaii)

Energy Technology Data Exchange (ETDEWEB)

Browder, Thomas E.

2013-08-31

Here we present a final report for the DOE award for the University of Hawaii High Energy Physics Group (UHHEPG) for the period from December 1, 2009 to May 31, 2013 (including a period of no-cost extension). The high energy physics (HEP) group at the University of Hawaii (UH) has been engaged in experiments at the intensity frontier studying flavor physics (Task A: Belle, Belle-II and Task B: BES) and neutrinos (Task C: SuperK, LBNE, Double Chooz, DarkSide, and neutrino R\\&D). On the energy frontier, new types of pixel detectors were developed for upgrades of the ATLAS experiment at the LHC (Task D). On the cosmic frontier, there were investigations of ultra high-energy neutrino astrophysics and the highest energy cosmic rays using special radio detection techniques (Task E: AMBER, ANITA R\\&D) and results of the analysis of ANITA data. In addition, we have developed new types of sophisticated and cutting edge instrumentation based on novel ``oscilloscope on a chip'' electronics (Task F). Theoretical physics research (Task G) is phenomenologically oriented and has studied experimental consequences of existing and proposed new theories relevant to the energy, cosmic and intensity frontiers. The senior investigators for proposal were T. E. Browder (Task A), F. A. Harris (Task B), P. Gorham (Task E), J. Kumar (Task G), J. Maricic (Task C), J. G. Learned (Task C), S. Pakvasa (Task G), S. Parker (Task D), S. Matsuno (Task C), X. Tata (Task G) and G. S. Varner (Tasks F, A, E).

The Astrophysics Science Division Annual Report 2009

Science.gov (United States)

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

2010-01-01

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

Goddard's Astrophysics Science Division Annual Report 2011

Science.gov (United States)

Centrella, Joan; Reddy, Francis; Tyler, Pat

2012-01-01

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

7Be(p, γ)8B and the high-energy solar neutrino flux

International Nuclear Information System (INIS)

Csoto, A.

1997-01-01

Despite thirty years of extensive experimental and theoretical work, the predicted solar neutrino flux is still in sharp disagreement with measurements. The solar neutrino measurements strongly suggest that the problem cannot be solved within the standard electroweak and astrophysical theories. Thus, the solar neutrino problem constitutes the strongest evidence for physics beyond the Standard Model. Whatever the solution of the solar neutrino problem turns out to be, it is of paramount importance that the input parameters of the underlying electroweak and solar theories rest upon solid ground. The most uncertain nuclear input parameter in standard solar models is the low-energy 7 Be(p, γ) 8 B radiative capture cross section. This reaction produces 8 B in the Sun, whose β + decay is the main source of the high-energy solar neutrinos. Here, the importance of the 7 Be(p, γ) 8 B reaction in predicting the high energy solar neutrino flux is discussed. The author presents a microscopic eight-body model and a potential model for the calculation of the 7 Be(p, γ) 8 B cross section

Old and New from Multifrequency Astrophysics

Directory of Open Access Journals (Sweden)

Franco Giovannelli

2014-12-01

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

Collisionless plasmas in astrophysics

CERN Document Server

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

2013-01-01

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

Improved predictions of nuclear data: A continued challenge in astrophysics

International Nuclear Information System (INIS)

Goriely, S.

2001-01-01

Although important effort has been devoted in the last decades to measure reaction cross sections and decay half-lives of interest in astrophysics, most of the nuclear astrophysics applications still require the use of theoretical predictions to estimate experimentally unknown rates. The nuclear ingredients to the reaction or weak interaction models should preferentially be estimated from microscopic or semi-microscopic global predictions based on sound and reliable nuclear models which, in turn, can compete with more phenomenological highly-parametrized models in the reproduction of experimental data. The latest developments made in deriving the nuclear inputs of relevance in astrophysics applications are reviewed. It mainly concerns nuclear structure properties (atomic masses, deformations, radii, etc...), nuclear level densities, nucleon and α-optical potentials, γ-ray and Gamow-Teller strength functions

Follow-up of high energy neutrinos detected by the ANTARES telescope