WorldWideScience

Sample records for astrophysical interest extracted

  1. Lithium induced nuclear reactions of astrophysical interest

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.P. [CIAE, China Institute of Atomic Energy, P. O. Box 275(1), Beijing 102413 (China); Li, Z.H.; Bai, X.X.; Wang, Y.B.; Lian, G.; Guo, B.; Su, J.; Zeng, S.; Wang, B.X.; Yan, S.Q.; Li, Y.J.; Li, E.T. [CIAE, China Institute of Atomic Energy, P. O. Box 275(46), Beijing 102413 (China)

    2010-03-01

    Systematic studies of nuclear astrophysical reactions induced by lithium isotopes using the unstable ion beam facility GIRAFFE in CIAE were performed. We have measured the angular distributions of some single nucleon transfer reactions, such as {sup 8}Li(d,p){sup 9}Li, {sup 8}Li(d,n){sup 9}Be and {sup 8}Li(p,d){sup 7}Li in inverse kinematics, and derived the astrophysical S-factors or reaction rates for {sup 8}Li(n,gamma){sup 9}Li and {sup 8}Li(p,gamma){sup 9}Be by using asymptotic normalization coefficient (ANC) or spectroscopic factor.

  2. Forbidden Transition Probabilities of Astrophysical Interest among ...

    Indian Academy of Sciences (India)

    Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately.

  3. Forbidden Transition Probabilities of Astrophysical Interest among ...

    Indian Academy of Sciences (India)

    astrophysical plasma densities are very low, the probability of collisions is small and many states decay by M1 or E2 ..... ences were computed according to the formula [gf (l) − gf (v)] ×100/max{gf(l), gf(v)}. Transition gf (l) gf (v). Diff. (%). 3d a 2G. −. 3d a 2D. 1.518E−11. 1.683E−11. 9.8. 3d a 2G. −. 3d a 2G. 5.290E−07.

  4. Structure of proton-rich nuclei of astrophysical interest

    Energy Technology Data Exchange (ETDEWEB)

    Roeckl, E. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)

    1998-06-01

    Recent experimental data concerning proton-rich nuclei between A=20 and A=100 are presented and discussed with respect to their relevance to the astrophysical rp process and to the calibration of solar neutrino detectors. (orig.)

  5. Laboratory Rotational Spectroscopy of Astrophysical Interesting Diatomic Hydrides

    Science.gov (United States)

    Halfen, DeWayne; Ziurys, L.

    2008-05-01

    Diatomic hydride are among the most common molecular species in the interstellar medium (ISM). The low molecular mass and thus moments of inertia cause their rotational spectra to lie entirely in the submillimeter and far-infrared regions. Hence, the future airborne and space-borne platforms, such as SOFIA and Herschel, are primed to explore these prevalent molecules. However, in order to detect these species in the ISM, their rotational spectra must first be measured in the laboratory. Using submillimeter direct absorption methods in the Ziurys laboratory, we have recorded the spectra of several diatomic hydrides of astrophysical interest. We have measured the pure rotational spectrum of MnH (X7Σ+: N = 0 - 1) and MnD (N = 2 - 3), as well as the deuterium and carbon-13 isotopologues of CH, CD (X2Πr: N = 1 - 1 and 1 - 2) and 13CH (N = 1 - 1). Manganese hydride and deuteride were created in a DC discharge of H2 or D2 and manganese vapor, generated in a Broida-type oven. CD and 13CH were produced in an AC discharge of argon and CD4 or 13CH4. For MnH, the five strongest manganese hyperfine transitions were recorded in its N = 0 - 1 transition, each of which are additionally split by hydrogen hyperfine interactions. CD and 13CH also have multiple hyperfine components due to the D, 13C, and/or H atoms. The direct measurement of these fundamental transitions will allow for unambiguous astronomical detections. The results of these studies will be presented.

  6. 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 2 H + , ortho/para selection rules in the chemistry of nitrogen hydrides, cyanides/iso-cyanides excitation in the ISM, CN excitation, radiative association with N 2 H 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)

  7. Astrophysics

    International Nuclear Information System (INIS)

    Harmanec, P.

    1987-01-01

    Volume 5 of the proceedings contains 62 papers of which 61 have been incorporated in INIS. They are divided by subject into several groups: early-type stars, late-type stars, binaries and multiple systems, theoretical considerations, ultraviolet stellar spectra, high energy astrophysics and binary stars. Many papers dealt with variable stars, star development and star models. (M.D.). 200 figs., 38 tabs., 1189 refs

  8. 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.

  9. Millimeter and Submillimeter Studies of O(^1D) Insertion Reactions to Form Molecules of Astrophysical Interest

    Science.gov (United States)

    Hays, Brian; Wehres, Nadine; Deprince, Bridget Alligood; Roy, Althea A. M.; Laas, Jacob; Widicus Weaver, Susanna L.

    2015-06-01

    While both the number of detected interstellar molecules and their chemical complexity continue to increase, understanding of the processes leading to their formation is lacking. Our research group combines laboratory spectroscopy, observational astronomy, and astrochemical modeling for an interdisciplinary examination of the chemistry of star and planet formation. This talk will focus on our laboratory studies of O(^1D) insertion reactions with organic molecules to produce molecules of astrophysical interest. By employing these reactions in a supersonic expansion, we are able to produce interstellar organic reaction intermediates that are unstable under terrestrial conditions; we then probe the products using millimeter and submillimeter spectroscopy. We benchmarked this setup using the well-studied O(^1D) + methane reaction to form methanol. After optimizing methanol production, we moved on to study the O(^1D) + ethylene reaction to form vinyl alcohol (CH_2CHOH), and the O(^1D) + methyl amine reaction to form aminomethanol (NH_2CH_2OH). Vinyl alcohol measurements have now been extended up to 450 GHz, and the associated spectral analysis is complete. A possible detection of aminomethanol has also been made, and continued spectral studies and analysis are underway. We will present the results from these experiments and discuss future applications of these molecular and spectroscopic techniques.

  10. 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.

  11. Extracting factors for interest rate scenarios

    Science.gov (United States)

    Molgedey, L.; Galic, E.

    2001-04-01

    Factor based interest rate models are widely used for risk managing purposes, for option pricing and for identifying and capturing yield curve anomalies. The movements of a term structure of interest rates are commonly assumed to be driven by a small number of orthogonal factors such as SHIFT, TWIST and BUTTERFLY (BOW). These factors are usually obtained by a Principal Component Analysis (PCA) of historical bond prices (interest rates). Although PCA diagonalizes the covariance matrix of either the interest rates or the interest rate changes, it does not use both covariance matrices simultaneously. Furthermore higher linear and nonlinear correlations are neglected. These correlations as well as the mean reverting properties of the interest rates become crucial, if one is interested in a longer time horizon (infrequent hedging or trading). We will show that Independent Component Analysis (ICA) is a more appropriate tool than PCA, since ICA uses the covariance matrix of the interest rates as well as the covariance matrix of the interest rate changes simultaneously. Additionally higher linear and nonlinear correlations may be easily incorporated. The resulting factors are uncorrelated for various time delays, approximately independent but nonorthogonal. This is in contrast to the factors obtained from the PCA, which are orthogonal and uncorrelated for identical times only. Although factors from the ICA are nonorthogonal, it is sufficient to consider only a few factors in order to explain most of the variation in the original data. Finally we will present examples that ICA based hedges outperforms PCA based hedges specifically if the portfolio is sensitive to structural changes of the yield curve.

  12. Direct measurement of nuclear cross-section of astrophysical interest: Results and perspectives

    Science.gov (United States)

    Cavanna, Francesca; Prati, Paolo

    2018-03-01

    Stellar evolution and nucleosynthesis are interconnected by a wide network of nuclear reactions: the study of such connection is usually known as nuclear astrophysics. The main task of this discipline is the determination of nuclear cross-section and hence of the reaction rate in different scenarios, i.e. from the synthesis of a few very light isotopes just after the Big Bang to the heavy element production in the violent explosive end of massive stars. The experimental determination of reaction cross-section at the astrophysical relevant energies is extremely difficult, sometime impossible, due to the Coulomb repulsion between the interacting nuclei which turns out in cross-section values down to the fbar level. To overcome these obstacles, several experimental approaches have been developed and the adopted techniques can be roughly divided into two categories, i.e. direct and indirect methods. In this review paper, the general problem of nuclear astrophysics is introduced and discussed from the point of view of experimental approach. We focus on direct methods and in particular on the features of low-background experiments performed at underground laboratory facilities. The present knowledge of reactions involved in the Big Bang and stellar hydrogen-burning scenarios is discussed as well as the ongoing projects aiming to investigate mainly the helium- and carbon-burning phases. Worldwide, a new generation of experiment in the MeV range is in the design phase or at the very first steps and decisive progresses are expected to come in the next years.

  13. 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.

  14. The Intersection of NASA Astrophysics Education and Public Outreach and Higher Education: A Special Interest Group Meeting

    Science.gov (United States)

    Sharma, M.; Smith, D.; Schultz, G.; Bianchi, L.; Blair, W.

    2011-09-01

    This paper presents highlights from a group discussion on how the NASA Science Mission Directorate (SMD) education and public outreach (EPO) community could better support undergraduate astronomy education through EPO products and resources - current and future - targeted at the college level. The discussion was organized by the SMD Astrophysics EPO Forum through a Special Interest Group Meeting at the 2010 ASP Annual Meeting in Boulder. Our session took advantage of the simultaneous presence of EPO professionals and the Cosmos in the Classroom participants to seek out diverse perspectives on and experiences in higher education.

  15. Precise mass measurements of astrophysical interest made with the Canadian Penning trap mass spectrometer

    International Nuclear Information System (INIS)

    Clark, J.A.; Barber, R.C.; Blank, B.; Boudreau, C.; Buchinger, F.; Crawford, J.E.; Gulick, S.; Hardy, J.C.; Heinz, A.; Lee, J.K.P.; Levand, A.F.; Moore, R.B.; Savard, G.; Seweryniak, D.; Sharma, K.S.; Sprouse, G.D.; Trimble, W.; Vaz, J.; Wang, J.C.; Zhou, Z.

    2004-01-01

    The processes responsible for the creation of elements more massive than iron are not well understood. Possible production mechanisms involve the rapid capture of protons (rp-process) or the rapid capture of neutrons (r-process), which are thought to occur in explosive astrophysical events such as novae, x-ray bursts, and supernovae. Mass measurements of the nuclides involved with uncertainties on the order of 100 keV or better are critical to determine the process 'paths', the energy output of the events, and the resulting nuclide abundances. Particularly important are the masses of 'waiting-point' nuclides along the rp-process path where the process stalls until the subsequent β decay of the nuclides. This paper will discuss the precise mass measurements made of isotopes along the rp-process and r-process paths using the Canadian Penning Trap mass spectrometer, including the mass of the critical waiting-point nuclide 68 Se

  16. Investigations of astrophysically interesting nuclear reactions by the use of gas target techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, J.W. [Inst. fuer Strahlenphysik, Univ. Stuttgart, Stuttgart (Germany)

    1998-06-01

    A brief review of the common properties of windowless and recirculating gas targets is presented. As example the Stuttgart gas target facility Rhinoceros in the extended and in the supersonic jet mode with its properties and techniques is explained, also with respect to gas purification techniques. Furthermore several typical experiments from the field of nuclear astrophysics with characteristic results are described (D({alpha},{gamma}){sup 6}Li, {sup 15}N({alpha},{gamma}){sup 19}F, {sup 16}O(p,{gamma}){sup 17}F, {sup 16}O({alpha},{gamma}){sup 20}Ne, {sup 20}Ne({alpha},{gamma}){sup 24}Mg, {sup 21}Ne({alpha},n){sup 24}Mg, {sup 18}O({alpha},n){sup 21}Ne, {sup 17}O({alpha},n){sup 20}Ne). In several cases the experimental sensitivity could be raised by up to a factor of 10{sup 6}. (orig.)

  17. 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...

  18. Extracting Communities of Interests for Semantics-Based Graph Searches

    Science.gov (United States)

    Nakatsuji, Makoto; Tanaka, Akimichi; Uchiyama, Toshio; Fujimura, Ko

    Users recently find their interests by checking the contents published or mentioned by their immediate neighbors in social networking services. We propose semantics-based link navigation; links guide the active user to potential neighbors who may provide new interests. Our method first creates a graph that has users as nodes and shared interests as links. Then it divides the graph by link pruning to extract practical numbers, that the active user can navigate, of interest-sharing groups, i.e. communities of interests (COIs). It then attaches a different semantic tag to the link to each representative user, which best reflects the interests of COIs that they are included in, and to the link to each immediate neighbor of the active user. It finally calculates link attractiveness by analyzing the semantic tags on links. The active user can select the link to access by checking the semantic tags and link attractiveness. User interests extracted from large scale actual blog-entries are used to confirm the efficiency of our proposal. Results show that navigation based on link attractiveness and representative users allows the user to find new interests much more accurately than is otherwise possible.

  19. Density functional theory for prediction of far-infrared vibrational frequencies: molecular crystals of astrophysical interest

    Science.gov (United States)

    Ennis, C.; Auchettl, R.; Appadoo, D. R. T.; Robertson, E. G.

    2017-11-01

    Solid-state density functional theory code has been implemented for the structure optimization of crystalline methanol, acetaldehyde and acetic acid and for the calculation of infrared frequencies. The results are compared to thin film spectra obtained from low-temperature experiments performed at the Australian Synchrotron. Harmonic frequency calculations of the internal modes calculated at the B3LYP-D3/m-6-311G(d) level shows higher deviation from infrared experiment than more advanced theory applied to the gas phase. Importantly for the solid-state, the simulation of low-frequency molecular lattice modes closely resembles the observed far-infrared features after application of a 0.92 scaling factor. This allowed experimental peaks to be assigned to specific translation and libration modes, including acetaldehyde and acetic acid lattice features for the first time. These frequency calculations have been performed without the need for supercomputing resources that are required for large molecular clusters using comparable levels of theory. This new theoretical approach will find use for the rapid characterization of intermolecular interactions and bonding in crystals, and the assignment of far-infrared spectra for crystalline samples such as pharmaceuticals and molecular ices. One interesting application may be for the detection of species of prebiotic interest on the surfaces of Kuiper-Belt and Trans-Neptunian Objects. At such locations, the three small organic molecules studied here could reside in their crystalline phase. The far-infrared spectra for their low-temperature solid phases are collected under planetary conditions, allowing us to compile and assign their most intense spectral features to assist future far-infrared surveys of icy Solar system surfaces.

  20. The Belgian repository of fundamental atomic data and stellar spectra (BRASS). I. Cross-matching atomic databases of astrophysical interest

    Science.gov (United States)

    Laverick, M.; Lobel, A.; Merle, T.; Royer, P.; Martayan, C.; David, M.; Hensberge, H.; Thienpont, E.

    2018-04-01

    Context. Fundamental atomic parameters, such as oscillator strengths, play a key role in modelling and understanding the chemical composition of stars in the Universe. Despite the significant work underway to produce these parameters for many astrophysically important ions, uncertainties in these parameters remain large and can propagate throughout the entire field of astronomy. Aims: The Belgian repository of fundamental atomic data and stellar spectra (BRASS) aims to provide the largest systematic and homogeneous quality assessment of atomic data to date in terms of wavelength, atomic and stellar parameter coverage. To prepare for it, we first compiled multiple literature occurrences of many individual atomic transitions, from several atomic databases of astrophysical interest, and assessed their agreement. In a second step synthetic spectra will be compared against extremely high-quality observed spectra, for a large number of BAFGK spectral type stars, in order to critically evaluate the atomic data of a large number of important stellar lines. Methods: Several atomic repositories were searched and their data retrieved and formatted in a consistent manner. Data entries from all repositories were cross-matched against our initial BRASS atomic line list to find multiple occurrences of the same transition. Where possible we used a new non-parametric cross-match depending only on electronic configurations and total angular momentum values. We also checked for duplicate entries of the same physical transition, within each retrieved repository, using the non-parametric cross-match. Results: We report on the number of cross-matched transitions for each repository and compare their fundamental atomic parameters. We find differences in log(gf) values of up to 2 dex or more. We also find and report that 2% of our line list and Vienna atomic line database retrievals are composed of duplicate transitions. Finally we provide a number of examples of atomic spectral lines

  1. Extracting Visited Points of Interest from Vehicle Trajectories

    DEFF Research Database (Denmark)

    Keles, Ilkcan; Schubert, Matthias; Kröger, Peer

    2017-01-01

    Identifying visited points of interest (PoIs) from vehicle trajectories remains an open problem that is difficult due to vehicles parking often at some distance from the visited PoI and due to some regions having a high PoI density. We propose a visited PoI extraction (VPE) method that identifies...... a precision@3 value of 0.8, indicating that VPE is able to model the relationship between the temporal features of a stop and the category of the visited PoI....

  2. Study of the reaction of astrophysical interest 60Fe(n,γ)61Fe via (d,pγ) transfer reaction

    International Nuclear Information System (INIS)

    Giron, S.

    2011-12-01

    60 Fe is of special interest in nuclear astrophysics. Indeed the recent observations of 60 Fe characteristic gamma-ray lines by the RHESSI and INTEGRAL spacecrafts allowed to measure the total flux of 60 Fe over the Galaxy. Moreover the observation in presolar grains of an excess of the daughter-nuclei of 60 Fe, 60 Ni, gives constraints on the conditions of formation of the early solar system. However, the cross-sections of some reactions involved in 60 Fe nucleosynthesis and included to stellar models are still uncertain. The destruction reaction of 60 Fe, 60 Fe(n, γ) 61 Fe, is one of them. The total cross-section can be separate into two contributions: the direct one, involving states below the neutron separation threshold of 61 Fe, and the resonant one.We improved 61 Fe spectroscopy in order to evaluate the direct capture part of the 60 Fe(n, γ) 61 Fe reaction cross-section. 60 Fe(n, γ) 61 Fe was thus studied via d( 60 Fe, pγ) 61 Fe transfer reaction with the CATS/MUST2/EXOGAM setup at LISE-GANIL. DWBA analysis of experimental proton differential cross-sections allowed to extract orbital angular momentum and spectroscopic factors of different populated states identified below the neutron threshold. A comparison of experimental results for 61 Fe with experimental results for similar nuclei and with shell-model calculations was also performed. (author) [fr

  3. Automated Image Registration Using Morphological Region of Interest Feature Extraction

    Science.gov (United States)

    Plaza, Antonio; LeMoigne, Jacqueline; Netanyahu, Nathan S.

    2005-01-01

    With the recent explosion in the amount of remotely sensed imagery and the corresponding interest in temporal change detection and modeling, image registration has become increasingly important as a necessary first step in the integration of multi-temporal and multi-sensor data for applications such as the analysis of seasonal and annual global climate changes, as well as land use/cover changes. The task of image registration can be divided into two major components: (1) the extraction of control points or features from images; and (2) the search among the extracted features for the matching pairs that represent the same feature in the images to be matched. Manual control feature extraction can be subjective and extremely time consuming, and often results in few usable points. Automated feature extraction is a solution to this problem, where desired target features are invariant, and represent evenly distributed landmarks such as edges, corners and line intersections. In this paper, we develop a novel automated registration approach based on the following steps. First, a mathematical morphology (MM)-based method is used to obtain a scale-orientation morphological profile at each image pixel. Next, a spectral dissimilarity metric such as the spectral information divergence is applied for automated extraction of landmark chips, followed by an initial approximate matching. This initial condition is then refined using a hierarchical robust feature matching (RFM) procedure. Experimental results reveal that the proposed registration technique offers a robust solution in the presence of seasonal changes and other interfering factors. Keywords-Automated image registration, multi-temporal imagery, mathematical morphology, robust feature matching.

  4. AN ITERATIVE SEGMENTATION METHOD FOR REGION OF INTEREST EXTRACTION

    Directory of Open Access Journals (Sweden)

    Volkan CETIN

    2013-01-01

    Full Text Available In this paper, a method is presented for applications which include mammographic image segmentation and region of interest extraction. Segmentation is a very critical and difficult stage to accomplish in computer aided detection systems. Although the presented segmentation method is developed for mammographic images, it can be used for any medical image which resembles the same statistical characteristics with mammograms. Fundamentally, the method contains iterative automatic thresholding and masking operations which is applied to the original or enhanced mammograms. Also the effect of image enhancement to the segmentation process was observed. A version of histogram equalization was applied to the images for enhancement. Finally, the results show that enhanced version of the proposed segmentation method is preferable because of its better success rate.

  5. Relativistic astrophysics

    CERN Document Server

    Price, R H

    1993-01-01

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

  6. Interest Extraction Using Relevance Feedback with Kernel Method

    Science.gov (United States)

    Hidekazu, Yanagimoto; Sigeru, Omatu

    In this paper, we propose interest extraction using the relevance feedback with the kernel method. In the field of machine learning, the kernel method has been used. Since the classifier using the kernel method creates a discriminant function in a feature space, the discriminant function is a nonlinear function in a input space. The kernel method is used for the Support Vector Machine (SVM), the Kernel PCA, and so on. The SVM set a discriminant hyperplane between positive data and negative data. Hence, a distance between the hyperplane and a training sample is not important in the SVM. It is difficult to use the SVM to score other samples. Our goal is to create a method which scores the other samples in the feature space. We propose the relevance feedback which is carried out in the feature space. Hence, this relevance feedback can deal with nonlinearity of data. We compare the proposed method with the common relevance feedback using test collection NTCIR2. Finally, we comfirm the proposed method is superior to the common method through simulations.

  7. Extraction of interesting organic compounds from olive oil waste

    Directory of Open Access Journals (Sweden)

    Jiménez, Ana

    2006-03-01

    Full Text Available In the olive fruits there is a large amount of bioactive compounds and substances of high interest. Many of them are known by owing health beneficial properties that contribute to protective effect of the virgin olive oil. During olive oil processing, most of them remain in the olive oil wastes. Although, olive-mill wastewater (OMWW or “alpechin”, olive oil cake (OOC, and the new by-product, known as “alperujo” in Spain and generated by the two-phase extraction process, represent a major disposal and potentially severe pollution problem for the industry, they are also promising source of substances of high value. This review summarises the last knowledge on the utilisation of residual products, with more than 90 references including articles and patents, which are promising with regard to future application. All these investigations have been classified into two options, the recovery of valuable natural constituents and the bioconversion into useful products.Existe una gran cantidad de compuestos bioactivos y de alto interés presentes en la aceituna. Muchos de ellos se conocen por las cualidades beneficiosas que aportan al aceite de oliva virgen. La mayoría permanecen en mayor cantidad en el subproducto de la extracción del aceite. Aunque, el alpechín, el orujo y el nuevo subproducto de extracción del aceite en dos fases, alperujo, representan un problema potencial de vertido y contaminación, también son una prometedora fuente de compuestos de alto valor. Esta revisión resume lo último que se conoce sobre la utilización de estos residuos en el campo anteriormente mencionado, con más de 90 referencias que incluyen artículos y patentes. Todas estas investigaciones han sido clasificadas en cuanto a la recuperación de constituyentes naturalmente presentes o en cuanto a la bioconversión de los residuos en sustancias de interés.

  8. 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.

  9. 78Kr(α,γ) reaction of astrophysical interest in inverse kinematics and the electronic screening effect on the beta decay

    International Nuclear Information System (INIS)

    Ujic, P.

    2011-12-01

    The thesis is constituted of two different topics related to astrophysics. The titles of these topics are: 'Alpha capture reaction in inverse kinematics, measurement of 78 Kr(α,γ) 82 Sr reaction' and 'Measurement of the radioactive decay of 19 O and 19 Ne implanted in niobium'. The goal of the first part of the thesis was to establish an experimental technique for measuring radiative alpha capture reaction at low energies in inverse kinematics. The measurement of these reactions is very important in astrophysics since it will help to improve the reliability of alpha particle optical model potentials which are used for prediction of cross sections of nuclear reaction used in different astrophysical models of supernovae explosions. In this part we insisted on a technical feasibility of this type of experiment. In the second part of the thesis, we examined the influence of the environment on the beta decay probability, in particular the influence of the electronic screening of Coulomb barrier of nuclei induced by Cooper pairs in superconductors. The indication of an extremely weak effect was noticed. (author)

  10. 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

  11. 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

  12. 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)

  13. Improved saliency toolbox/Itti model for region of interest extraction

    Science.gov (United States)

    He, Dong-Jian; Liu, Shang-Wang; Liang, Xin-Hong; Cai, Cheng

    2011-09-01

    The saliency toolbox (STB)/Itti model is an outstanding computational selective visual attention model. In this paper, we propose an improved STB/Itti model to overcome the drawback of STB/Itti--its output ``saliency map'' is not large enough for region of interest (ROI) extraction. First, we employ a simplified pulse coupled neural network (PCNN) with a special input image, and more importantly, the PCNN does not require iterations. Subsequently, the PCNN takes the place of the winner-take-all network in STB/Itti. Experimental results show that the improved STB/Itti model works well for ROI extraction, with the mean area under the curve value of 0.8306 and robustness against noise and geometric attacks. The proposed model can greatly enhance the performances of both STB/Itti and PCNN model in image processing.

  14. Infrared image segmentation based on region of interest extraction with Gaussian mixture modeling

    Science.gov (United States)

    Yeom, Seokwon

    2017-05-01

    Infrared (IR) imaging has the capability to detect thermal characteristics of objects under low-light conditions. This paper addresses IR image segmentation with Gaussian mixture modeling. An IR image is segmented with Expectation Maximization (EM) method assuming the image histogram follows the Gaussian mixture distribution. Multi-level segmentation is applied to extract the region of interest (ROI). Each level of the multi-level segmentation is composed of the k-means clustering, the EM algorithm, and a decision process. The foreground objects are individually segmented from the ROI windows. In the experiments, various methods are applied to the IR image capturing several humans at night.

  15. 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...

  16. 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

  17. 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)

  18. 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

  19. A new determination of the E1 amplitude of 12C(α,γ)16O at energies of astrophysical interest

    Science.gov (United States)

    Gialanella, L.; Campajola, L.; D'Onofrio, A.; Imbriani, G.; Ordine, A.; Roca, V.; Romano, M.; Sabbarese, C.; Terrasi, F.; Aliotta, M.; Rogalla, D.; Strieder, F.; Theis, S.; Rolfs, C.; Schümann, F.; Trautvetter, H. P.; Gyürki, G.; Somorjai, E.; Greife, U.; Agodi, C.; Alba, R.; del Zoppo, A.; Figuera, P.; Sapienza, P.

    2002-04-01

    The reaction 12C(α,γ)16O has a strong influence on both stellar evolution and nucleosynthesis after the helium burning stage in massive stars. The E1 amplitude of this astrophysical important reaction was measured in inverse kinematics using a 4He windowless gas target and an intense 12C ion beam in combination with an array of HPGe detectors. The results of this measurement were extrapolated to the relevant energy for helium burning (E0=300 keV) using the R-matrix formalism of nuclear reactions. The error on the extrapolated value was determined via a Monte Carlo procedure. The results of this experiment and of their extrapolation to E0 are presented and compared with previous data. .

  20. Astrophysics today

    International Nuclear Information System (INIS)

    Cameron, A.G.W.

    1984-01-01

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

  1. Relativistic Astrophysics

    Science.gov (United States)

    Jones, Bernard J. T.; Markovic, Dragoljub

    1997-06-01

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

  2. Effect of alpha states in the 16O+12C scattering and in the 12C +α → 16O capture reaction of astrophysical interest

    International Nuclear Information System (INIS)

    Morais, M.C.; Lichtenthaele, R.; Arazi, A.; Hojman, D.; Cardona, M.A.; Fimiani, L.; Carnelli, P.F.; Marti, G.V.; Pacheco, A.J.; Martinez Heimann, D.; Negri, A.E.; Capurro, O.A.; Niello, Fernandez; Montero, P.

    2011-01-01

    Full text: The 16 O+ 12 C elastic scattering was investigated considering the effect of exchange of an alpha particle between projectile and target leading to the same nuclei of the entrance channel (elastic transfer). Angular distributions were analyzed in an energy range from 8.55 MeV to 56.57 MeV in the center of mass frame. The Coulomb barrier is around 11MeV for this system. Measurements of angular distributions of elastic and inelastic transfer reactions to states of the 16 O in the 16 O+ 12 C system were performed at the TANDAR Laboratory in Buenos Aires, using an 16 O beam of E lab = 46; 26 MeV. The transfer angular distributions were analyzed by DWBA using the computer code FRESCO. Those measurements provided the spectroscopic factors of 12 C + α → 16 O for the ground state and for J π = 2 + and J π = 1 - 16 O excited states, both just below the α-threshold at 7.16 MeV. The Asymptotic Normalization Coefficient (ANC) for the J π = 2 + state was obtained (1.05 ±0,13(10 5 fm -1/2 )) and used to calculate the reduced width of this state, with this value a R-matrix calculation was performed to determine the astrophysical S-factor in energies around the Gamow peak, S(E2)=37keVb. (author)

  3. Observational astrophysics

    CERN Document Server

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

    2012-01-01

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

  4. 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.

  5. Stellar astrophysics

    International Nuclear Information System (INIS)

    1987-01-01

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

  6. Important plasma problems in astrophysics

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1995-01-01

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

  7. 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

  8. Nuclear astrophysics from direct reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C. [Department of Physics, Texas A and M University, Commerce, TX 75429 (United States)]. e-mail: carlos_bertulani@tamu-commerce.edu

    2008-12-15

    Accurate nuclear reaction rates are needed for primordial nucleosynthesis and hydrostatic burning in stars. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies. In recent years direct reactions have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental techniques and theoretical efforts, which are the subject of this presentation. (Author)

  9. Physics, Astrophysics and Cosmology with Gravitational Waves

    Directory of Open Access Journals (Sweden)

    Sathyaprakash B. S.

    2009-03-01

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

  10. Physics, Astrophysics and Cosmology with Gravitational Waves.

    Science.gov (United States)

    Sathyaprakash, B S; Schutz, Bernard F

    2009-01-01

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

  11. 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)

  12. 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

  13. Electric dipole moment function of the X1 Sigma/+/ state of CO - Vibration-rotation matrix elements for transitions of gas laser and astrophysical interest

    Science.gov (United States)

    Chackerian, C., Jr.

    1976-01-01

    The electric dipole moment function of the ground electronic state of carbon monoxide has been determined by combining numerical solutions of the radial Schrodinger equation with absolute intensity data of vibration-rotation bands. The derived dipole moment function is used to calculate matrix elements of interest to stellar astronomy and of importance in the carbon monoxide laser.

  14. 76 FR 7882 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2011-02-11

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  15. 77 FR 8288 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2012-02-14

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  16. 77 FR 22614 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2012-04-16

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  17. 78 FR 11685 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2013-02-19

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  18. 78 FR 22346 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2013-04-15

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  19. 76 FR 19793 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting via Teleconference

    Science.gov (United States)

    2011-04-08

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting...), the National Science Foundation announces the following meeting: Name: Astronomy and Astrophysics... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

  20. Optimization of a coherent synchrotron radiation source in the Tera-hertz range for high-resolution spectroscopy of molecules of astrophysical interest

    International Nuclear Information System (INIS)

    Barros, J.

    2012-01-01

    Fourier Transform spectroscopy is the most used multiplex tool for high-resolution measurements in the infrared range. Its extension to the Tera-hertz domain is of great interest for spectroscopic studies of interstellar molecules. This application is however hampered by the lack of dedicated, broadband sources with a sufficient intensity and stability. In this work, Coherent Synchrotron Radiation (CSR) was used as a source for molecular spectroscopy at high resolution on the AILES infrared and Tera-hertz beamline of SOLEIL synchrotron. The beamline being optimized for far-infrared, we could characterize the properties of CSR and compare them to the incoherent synchrotron radiation. A double detection system allowed to correct the effect of the source-related instabilities, hence to significantly increase the signal-to-noise ratio. Pure rotational spectra were measured using these developments. The case of the propynal molecule, for which a refined set of rotational and centrifugal distortion constants was calculated, proves the complementarity between CSR and the classical microwave or infrared sources. (author)

  1. Advanced LIGO: sources and astrophysics

    International Nuclear Information System (INIS)

    Creighton, Teviet

    2003-01-01

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

  2. Extraction of medically interesting 188Re-perrhenate in methyl ethyl ketone for concentration purposes

    International Nuclear Information System (INIS)

    Mushtaq, A.; Bukhari, T.H.; Khan, I.U.

    2007-01-01

    The high bolus volumes (20-40mL) of the generator-produced Rhenium-188 require post elution concentration of the eluate for the preparation of a dissolved β - source and radiopharmaceuticals labeled with Re-188 for radiotherapy. Solvent extraction of 188 Re in methyl ethyl ketone was studied. With the increase of organic phase volume, extraction of 188 Re was enhanced while mixing time of aqueous and organic phases did not show any significant effect on the extractability of 188 Re in the organic phase. Almost 80% of 188 Re was extracted in methyl ethyl ketone at a volume ratio of 1:2 for aqueous and organic phases. By evaporation/distillation of methyl ethyl ketone, 188 Re was concentrated and dissolved in the desired volume of physiological saline. (orig.)

  3. Determination by transfer reaction of alpha widths in fluorine for astrophysical interest; Determination par reaction de transfert de largeurs alpha dans le fluor 19. Applications a l'astrophysique

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Santos, F. de

    1995-04-15

    The nucleosynthesis of fluorine is not known. Several astrophysical models predict the alpha radiative capture onto N{sup 15} as the main fluorine production reaction. In the expression of the reaction rate, one parameter is missing: the alpha width of the resonance on the E = 4.377 MeV level in fluorine. A direct measurement is excluded due to the very low cross-section expected. We have determined this alpha width using a transfer reaction followed by analyses with FR-DWBA (Finite Range Distorted Wave Born Approximation) in a simple cluster alpha model. This experiment was carried out with a Li{sup 7} beam with E = 28 MeV onto a N{sup 15} gas target. The 16 first levels were studied. Spectroscopic factors were extracted for most of them. Alpha widths for unbound levels were determined. Many alpha width were compared with known values from direct reaction and the differences lie within the uncertainty range (factor 2). The alpha width for the E = 4.377 MeV level was determined ({gamma}{sub {alpha}} = 1.5*10{sup -15} MeV), its value is about 60 times weaker than the used value. The influence of our new rate was studied in AGB (Asymptotic Giant Branch) stars during thermal pulses. In this model the alteration is sensitive. (author)

  4. In vitro antimicrobial activity of Brazilian medicinal plant extracts against pathogenic microorganisms of interest to dentistry.

    Science.gov (United States)

    Pereira, Elizete Maria; Gomes, Rafael Tomaz; Freire, Natália Ribeiro; Aguiar, Evandro Guimarães; Brandão, Maria das Graças Lins; Santos, Vagner Rodrigues

    2011-03-01

    This study evaluated the susceptibility of oral pathogenic microorganisms Candida albicans, Streptococcus mutans, Staphylococcus aureus, and Aggregatibacter actinomycetemcomitans to Brazilian medicinal plant extracts of Schinus terebinthifolius (aroeira), Croton campestris (velame), Lafoensia pacari (pacari), Centaurium erythraea (centáurea), Stryphnodendron adstringens (barbatimão), and Anacardium humile (cajuzinho-docerrado), as compared to standardized antimicrobial agents (nystatin, chloramphenicol and tetracycline hydrochloride). Ethanol, hexane and butane fractions from stem barks, rinds, leaves, and/or roots were extracted and tested. Antimicrobial diffusion agar test and MIC were performed according to CLSI. After 24 h of incubation at 37 °C, the diameter of inhibition zones and spectrophotometer readings were measured and compared. The results were reported as means ± standard deviation (M ± SD). With the exception of five extracts that showed no antimicrobial activity, all the extracts tested showed antimicrobial activity, in different levels. This study suggests that extracts from the plants tested could be an alternative therapeutic option for infectious conditions of the oral cavity, such as denture stomatitis, dental caries, and periodontitis. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Forbidden Transition Probabilities of Astrophysical Interest among ...

    Indian Academy of Sciences (India)

    Atomic structure calculations—atomic data—oscillator strength—lifetimes. 1. Introduction. Vanadium transition data are useful in a wide range of scientific applications. Ionized vanadium, for example, has been used in plasma diagnosis (Wagatsuma & Danzaki. 1999), where physical properties such as electron temperature ...

  6. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

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

  7. Regions-of-interest extraction from remote sensing imageries using visual attention modelling

    Science.gov (United States)

    Tan, Hui Li; Fan, Jiayuan; Toomik, Maria; Lu, Shijian

    2016-10-01

    Processing and analysing large volume of remote sensing data is both labour intensive and time consuming. Therefore, there is a need to effectively and efficiently identify meaningful regions in these remote sensing data for timely resource management. In this paper, we propose a visual attention model for identifying regions-of-interest in remote sensing data. The proposed model incorporates both bottom-up spatial saliency and top-down objectness, by fusing a co-occurrence histogram saliency model with the BING objectness model. The co-occurrence histogram saliency model is constructed by first building a 2D co-occurrence histogram that captures co-occurrence and occurrence of image intensities, and then using the 2D co-occurrence histogram to model local and global saliency. On the other hand, the BING objectness model is constructed by resizing image intensities in variable-sized windows to 8x8 windows, and then using the norms of the gradients in the 8x8 windows as features to train a generic objectness measure. Our experimental results show that the proposed model can effectively and efficiently identify regions-of-interest in remote sensing data. The proposed model may be applied in various remote sensing applications such as anomaly detection, urban area detection, target detection, or land use classification.

  8. Conflicts of interests on the issue of Timber Exploitation within the Chico Mendes Extractive Reserve, Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Alfredo Celso Fantini

    2009-08-01

    Full Text Available This paper analyzes the problematic situation of commercial timber exploitation as a land use option in the community of Rio Branco, located in the Chico Mendes Extractive Reserve, Acre, Brazil, and examines the controversial implementation of the Community Forest Management Project (CFMP. Interviews with extractivists and representatives from nine government and non-government organizations resulted in a list of eight desired land use practices. Each of the interviewees was asked to rank the land uses according to his/her individual priorities. Through the use of the Indicator of Sustainability in Systems of Interests (ISSI, the degree of convergence was calculated between the interest (rank of priorities of each extractivist and the collective interest, as well as between the interests of the extractivists and other institutions. Non-Timber Forest Products (NTFPs management and shifting cultivation are the preferred land uses noted by extractivists who are ‘non-participants’ in the CFMP, who attribute minimum priority to timber exploitation. Those who participate in CFMP rank timber exploitation as their top priority. Members of government institutions and NGOs indicated a preference for land uses that cause less impact on the forest, choices that are closer to the group of ‘non-participant’ extractivists than to the ‘participant’ group. In a second round of ranking, CFMP ‘participants’ significantly changed their previous choices, this time electing management of NTFPs and shifting cultivation as their top priorities. The results revealed that the issue of timber exploitation in the Chico Mendes Extractive Reserve constitutes a complex system of interests and that some extractivists do not feel confident in relation to the consequences of the implementation of the project, i.e., the project was not sufficiently mature to be implemented.

  9. High energy astrophysical techniques

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

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

  10. Astrophysics and Cosmology

    CERN Document Server

    García-Bellido, J

    2000-01-01

    These notes are intended as an introductory course for experimental particle physicists interested in the recent developments in astrophysics and cosmology. I will describe the standard Big Bang theory of the evolution of the universe, with its successes and shortcomings, which will lead to inflationary cosmology as the paradigm for the origin of the global structure of the universe as well as the origin of the spectrum of density perturbations responsible for structure in our local patch. I will present a review of the very rich phenomenology that we have in cosmology today, as well as evidence for the observational revolution that this field is going through, which will provide us, in the next few years, with an accurate determination of the parameters of our standard cosmological model.

  11. Limits of Astrophysics with Gravitational-Wave Backgrounds

    Directory of Open Access Journals (Sweden)

    Thomas Callister

    2016-08-01

    Full Text Available The recent Advanced LIGO detection of gravitational waves from the binary black hole GW150914 suggests there exists a large population of merging binary black holes in the Universe. Although most are too distant to be individually resolved by advanced detectors, the superposition of gravitational waves from many unresolvable binaries is expected to create an astrophysical stochastic background. Recent results from the LIGO and Virgo Collaborations show that this astrophysical background is within reach of Advanced LIGO. In principle, the binary black hole background encodes interesting astrophysical properties, such as the mass distribution and redshift distribution of distant binaries. However, we show that this information will be difficult to extract with the current configuration of advanced detectors (and using current data analysis tools. Additionally, the binary black hole background also constitutes a foreground that limits the ability of advanced detectors to observe other interesting stochastic background signals, for example, from cosmic strings or phase transitions in the early Universe. We quantify this effect.

  12. Technology Development for a Neutrino Astrophysical Observatory

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  13. Astrophysics of Wormholes

    OpenAIRE

    Kardashev, N. S.; Novikov, I. D.; Shatskiy, A. A.

    2006-01-01

    We consider the hypothesis that some active galactic nuclei and other compact astrophysical objects may be current or former entrances to wormholes. A broad mass spectrum for astrophysical wormholes is possible. We consider various new models of the static wormholes including wormholes maintained mainly by an electromagnetic field. We also discuss observational effects of a single entrance to wormhole and a model for a binary astrophysical system formed by the entrances of wormholes with magn...

  14. 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.

  15. Particle Physics & Astrophysics (PPA)

    Data.gov (United States)

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

  16. 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

  17. 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.)

  18. Black holes in astrophysics

    International Nuclear Information System (INIS)

    Narayan, Ramesh

    2005-01-01

    This paper reviews the current status of black hole (BH) astrophysics, focusing on topics of interest to a physics audience. Astronomers have discovered dozens of compact objects with masses greater than 3M o-dot , the likely maximum mass of a neutron star. These objects are identified as BH candidates. Some of the candidates have masses ∼5M o-dot -20M o-dot and are found in x-ray binaries, while the rest have masses ∼10 6 M o-dot -10 9.5 M o-dot and are found in galactic nuclei. A variety of methods are being tried to estimate the spin parameters of the candidate BHs. There is strong circumstantial evidence that many of the objects have event horizons, so there is good reason to believe that the candidates are true BHs. Recent MHD simulations of magnetized plasma accreting on rotating BHs seem to hint that relativistic jets may be produced by a magnetic analogue of the Penrose process

  19. Characterization of Non-Anthocyanic Flavonoids in Some Hybrid Red Grape Extracts Potentially Interesting for Industrial Uses

    Directory of Open Access Journals (Sweden)

    Mirko De Rosso

    2015-10-01

    Full Text Available Previous studies showed that hybrid grapes often have qualitatively and quantitatively higher polyphenolic contents than the common V. vinifera grape varieties. In general, these compounds are studied for grape chemotaxonomy and for nutraceutical purposes due to their relevant antioxidant activity. Non-anthocyanic flavonoid composition of five red hybrid grape varieties produced by crossing of V. vinifera, V. aestivalis, V. cinerea, V. berlandieri, V. labrusca, V. lincecumii, and V. rupestris were studied by liquid chromatography/high-resolution mass spectrometry. Thirty-one compounds were identified, including methylnaringenin, a tetrahydroxy-dimethoxyflavanone-hexoside, two flavonols (quercetin and a pentahydroxyflavone isomer, 20 glycoside flavonols (four quercetin, two myricetin, two kaempferol, three isorhamnetin, one laricitrin, two syringetin, one kaempferide and two dihydroflavonol derivatives; myricetin-glucoside-glucuronide; myricetin-diglucoside; syringetin-dihexoside, three flavan-3-ols (−-epicatechin, (+-catechin, (−-epicatechin gallate and four proantocyanidins (procyanidin B1, procyanidin B2, procyanidin B3 or B4/B5, procyanidin T2 or T3/T4/C1. Seibel 19881, Seyve Villard 12-347 and Seyve Villard 29-399 were particularly rich in polyphenols. These findings emphasize that these grapes are especially interesting for the production of antioxidant extracts for nutraceutical and pharmaceutical uses.

  20. Astrophysics for Physicists

    Science.gov (United States)

    Choudhuri, Arnab Rai

    2010-03-01

    1. Introduction; 2. Interaction of radiation with matter; 3. Stellar astrophysics I: basic theoretical ideas and observational data; 4. Stellar astrophysics II: nucleosynthesis and other advanced topics; 5. End states of stellar collapse; 6. Our galaxy and its interstellar matter; 7. Elements of stellar dynamics; 8. Elements of plasma astrophysics; 9. Extragalactic astronomy; 10. The spacetime dynamics of the Universe; 11. The thermal history of the Universe; 12. Elements of tensors and general relativity; 13. Some applications of general relativity; 14. Relativistic cosmology; Appendixes; References; Index.

  1. 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

  2. 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

  3. The Trojan Horse Method in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-19

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

  4. The Trojan Horse Method in nuclear astrophysics

    Science.gov (United States)

    Spitaleri, C.; Cherubini, S.; del Zoppo, A.; di Pietrob, A.; Figuerab, P.; Gulino, M.; Lattuadab, M.; Miljanić, D.; Musumarra, A.; Pellegriti, M. G.; Pizzone, R. G.; Rolfs, C.; Romano, S.; Tudisco, S.; Tumino, A.

    2003-05-01

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

  5. The Trojan Horse Method in nuclear astrophysics

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  6. Reactor neutrons in nuclear astrophysics

    OpenAIRE

    Reifarth, R.; Glorius, J.; Gobel, K.; Heftrich, T.; Jentschel, M.; Jurado, B.; Käppeler, F.; Köster, U.; Langer, C.; Litvinov, Y.A.; Weigand, M.

    2017-01-01

    The huge neutron fluxes offer the possibility to use research reactors to produce isotopes of interest, which can be investigated afterwards. An example is the half-lives of long-lived isotopes like 129I. A direct usage of reactor neutrons in the astrophysical energy regime is only possible, if the corresponding ions are not at rest in the laboratory frame. The combination of an ion storage ring with a reactor and a neutron guide could open the path to direct measurements of neutron-induced c...

  7. 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

  8. High energy astrophysics

    International Nuclear Information System (INIS)

    Engel, A.R.

    1979-01-01

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

  9. 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

  10. 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.

  11. Theoretical physics and astrophysics

    CERN Document Server

    Ginzburg, Vitalii Lazarevich

    1979-01-01

    The aim of this book is to present, on the one hand various topics in theoretical physics in depth - especially topics related to electrodynamics - and on the other hand to show how these topics find applications in various aspects of astrophysics. The first text on theoretical physics and astrophysical applications, it covers many recent advances including those in X-ray, &ggr;-ray and radio-astronomy, with comprehensive coverage of the literature

  12. 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

  13. Astrophysical and atmospheric neutrinos

    International Nuclear Information System (INIS)

    Lee, H.

    1986-01-01

    The low energy ( 1 TeV) astrophysical neutrino flux by a nearly model-independent analytic method for estimate the ultra-high energy neutrino flux from active astrophysical compact objects by comparison with the observed gamma ray flux at comparable energies. Applied to several known gamma ray sources, the calculation shows the neutrino flux from them to be only marginally detectable by DUMAND-size underwater detectors

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. B. B. Nath. 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.

  15. 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.

  16. 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.)

  17. Houdini for Astrophysical Visualization

    Science.gov (United States)

    Naiman, J. P.; Borkiewicz, Kalina; Christensen, A. J.

    2017-05-01

    The rapid growth in scale and complexity of both computational and observational astrophysics over the past decade necessitates efficient and intuitive methods for examining and visualizing large data sets. Here, we discuss some newly developed tools used to import and manipulate astrophysical data into the three-dimensional visual effects software, Houdini. This software is widely used by visual effects artists, but a recently implemented Python API now allows astronomers to more easily use Houdini as a visualization tool. This paper includes a description of features, workflow, and various example visualizations. The project website, www.ytini.com, is aimed at a scientific audience and contains Houdini tutorials and links to the Python script Bitbucket repository to simplify the process of importing and rendering astrophysical data.

  18. 78 FR 2450 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-01-11

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883...) on issues within the field of astronomy and astrophysics that are of mutual interest and concern to...

  19. 78 FR 61400 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2013-10-03

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting...) on issues within the field of astronomy and astrophysics that are of mutual interest and concern to...

  20. 76 FR 5214 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2011-01-28

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting... within the field of astronomy and astrophysics that are of mutual interest and concern to the agencies...

  1. 77 FR 54615 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2012-09-05

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following Astronomy and Astrophysics Advisory Committee ( 13883) meeting... on issues within the field of astronomy and astrophysics that are of mutual interest and concern to...

  2. 75 FR 7295 - Astronomy and Astrophysics Advisory Committee #13883; Notice of Meeting

    Science.gov (United States)

    2010-02-18

    ... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee 13883; Notice of Meeting... Science Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee... within the field of astronomy and astrophysics that are of mutual interest and concern to the agencies...

  3. Statistics and Informatics in Space Astrophysics

    Science.gov (United States)

    Feigelson, E.

    2017-12-01

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

  4. Astrophysics in a nutshell

    CERN Document Server

    Maoz, Dan

    2016-01-01

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

  5. Theoretical astrophysics an introduction

    CERN Document Server

    Bartelmann, Matthias

    2013-01-01

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

  6. NASA Astrophysics EPO Community: Enhancing STEM Instruction

    Science.gov (United States)

    Bartolone, L.; Manning, J.; Lawton, B.; Meinke, B. K.; Smith, D. A.; Schultz, G.; NASA Astrophysics EPO community

    2015-11-01

    The NASA Science Mission Directorate (SMD) Astrophysics Education and Public Outreach (EPO) community and Forum work together to capitalize on the cutting-edge discoveries of NASA Astrophysics missions to enhance Science, Technology, Engineering, and Math (STEM) instruction. In 2010, the Astrophysics EPO community identified online professional development for classroom educators and multiwavelength resources as a common interest and priority for collaborative efforts. The result is NASA's Multiwavelength Universe, a 2-3 week online professional development experience for classroom educators. The course uses a mix of synchronous sessions (live WebEx teleconferences) and asynchronous activities (readings and activities that educators complete on their own on the Moodle, and moderated by course facilitators). The NASA SMD Astrophysics EPO community has proven expertise in providing both professional development and resources to K-12 Educators. These mission- and grant-based EPO programs are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present examples of how the NASA Astrophysics EPO community and Forum engage the K-12 education community in these ways, including associated metrics and evaluation findings.

  7. Chilean berry Ugni molinae Turcz. fruit and leaves extracts with interesting antioxidant, antimicrobial and tyrosinase inhibitory properties.

    Science.gov (United States)

    López de Dicastillo, Carol; Bustos, Fernanda; Valenzuela, Ximena; López-Carballo, Gracia; Vilariño, Jose M; Galotto, Maria Jose

    2017-12-01

    The knowledge of the biological properties of fruits and leaves of murta (Ugni molinae Turcz.) has been owned by native Chilean culture. The present study investigated the phenolic content, the antioxidant, antimicrobial and anti-tyrosinase activities of different murta fruit and leaves extracts to approach their uses on future food, pharmaceutical and cosmetic applications. Extractions of murta fruit and leaves were carried out under water, ethanol and ethanol 50%. Phenolic content of these extracts was measured through Folin Ciocalteu test and the antioxidant power by four different antioxidant systems (ORAC, FRAP, DPPH and TEAC assays) owing to elucidate the main mechanism of antioxidant. Some flavonoids, such as rutin, isoquercitrin and quercitrin hydrate were identified and quantified through HPLC analysis. Antimicrobial activity was determined measuring minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values against Escherichia coli and Listeria monocytogenes, and the effect of these extracts on L. monocytogenes was confirmed by flow cytometry. Highest contents of polyphenol compounds were obtained in hydroalcoholic extracts (28±1mggallicacid/g dry fruit, and 128±6mggallicacid/g dry leaves). The same trend was found for the values of biological properties: hydroalcoholic extracts showed the strongest activities. Leaves presented higher antioxidant, antimicrobial and anti-tyrosinase properties than murta fruit. Highest antioxidant activity values according to ORAC, FRAP, TEAC and DPPH were 80±8mgTrolox/g, 70±2mgTrolox/g, 87±8mgTrolox/g and 110±12mgTrolox/g, respectively, for murta fruit samples, and 280±10mgTrolox/g, 192±4mgTrolox/g, 286±13mgTrolox/g and 361±13mgTrolox/g, respectively, for murta leaves. These activities were confirmed by HPLC analysis that revealed highest presence of analyzed compounds on leaves hydroalcoholic extract. Regarding to antimicrobial analysis, hydroalcoholic leaves extract presented the

  8. The NASA Astrophysics Program

    Science.gov (United States)

    Zebulum, Ricardo S.

    2011-01-01

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

  9. Astrophysics: An Integrative Course

    Science.gov (United States)

    Gutsche, Graham D.

    1975-01-01

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

  10. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure bas...

  11. 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,

  12. In situ genomic DNA extraction for PCR analysis of regions of interest in four plant species and one filamentous fungi

    Directory of Open Access Journals (Sweden)

    Luis E. Rojas

    2014-07-01

    Full Text Available The extraction methods of genomic DNA are usually laborious and hazardous to human health and the environment by the use of organic solvents (chloroform and phenol. In this work a protocol for in situ extraction of genomic DNA by alkaline lysis is validated. It was used in order to amplify regions of DNA in four species of plants and fungi by polymerase chain reaction (PCR. From plant material of Saccharum officinarum L., Carica papaya L. and Digitalis purpurea L. it was possible to extend different regions of the genome through PCR. Furthermore, it was possible to amplify a fragment of avr-4 gene DNA purified from lyophilized mycelium of Mycosphaerella fijiensis. Additionally, it was possible to amplify the region ap24 transgene inserted into the genome of banana cv. `Grande naine' (Musa AAA. Key words: alkaline lysis, Carica papaya L., Digitalis purpurea L., Musa, Saccharum officinarum L.

  13. 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.

  14. 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.

  15. Astrophysics a new approach

    CERN Document Server

    Kundt, Wolfgang

    2005-01-01

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

  16. 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.

  17. Allen's astrophysical quantities

    CERN Document Server

    2000-01-01

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

  18. Integrated astrophysical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, T. A.; Eastman, R. G.; Dubois, P.; Eltgroth, P. G.; Gentile, N.; Jedamzik, K.; Wilson, J. R.

    1997-06-03

    In this project, we have developed prototype techniques for defining and extending a variety of astrophysical modeling capabilities, including those involving multidimensional hydrodynamics, complex transport, and flexibly-coupled equation-of state and nuclear reaction networks. As expected, this project is having both near-term payoffs in understanding complex astrophysical phenomena, as well as significant spin-offs in terms of people and ideas to related ASCI code efforts. Most of our work in the first part of this project was focused on the modularization, extension, and initial integration of 4 previously separate and incommensurate codes: the stellar evolution/explosion code KEPLER; the non-LTE spectral line transport code, EDDINGTON, used for modeling supernovae spectra; the 3-D smooth particle hydro code, PIP; and the discontinuous-finite-element, 3D hydro module from the lCF3D code.

  19. Astrophysical black holes

    CERN Document Server

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

    2016-01-01

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

  20. Astrophysical terms in Armenian

    Science.gov (United States)

    Yeghikian, A. G.

    2015-07-01

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

  1. 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.

  2. Coulomb dissociation studies for astrophysical thermonuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

  3. 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.

  4. Technology development for a neutrino astrophysical observatory. Letter of intent

    International Nuclear Information System (INIS)

    Chaloupka, V.; Cole, T.; Crawford, H.J.

    1996-02-01

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

  5. Exploring Astrophysical Magnetohydrodynamics in the Laboratory

    Science.gov (United States)

    Manuel, Mario

    2014-10-01

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

  6. Numerical Methods for Radiation Magnetohydrodynamics in Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R I; Stone, J M

    2007-11-20

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

  7. Simple and efficient method for region of interest value extraction from picture archiving and communication system viewer with optical character recognition software and macro program.

    Science.gov (United States)

    Lee, Young Han; Park, Eun Hae; Suh, Jin-Suck

    2015-01-01

    The objectives are: 1) to introduce a simple and efficient method for extracting region of interest (ROI) values from a Picture Archiving and Communication System (PACS) viewer using optical character recognition (OCR) software and a macro program, and 2) to evaluate the accuracy of this method with a PACS workstation. This module was designed to extract the ROI values on the images of the PACS, and created as a development tool by using open-source OCR software and an open-source macro program. The principal processes are as follows: (1) capture a region of the ROI values as a graphic file for OCR, (2) recognize the text from the captured image by OCR software, (3) perform error-correction, (4) extract the values including area, average, standard deviation, max, and min values from the text, (5) reformat the values into temporary strings with tabs, and (6) paste the temporary strings into the spreadsheet. This principal process was repeated for the number of ROIs. The accuracy of this module was evaluated on 1040 recognitions from 280 randomly selected ROIs of the magnetic resonance images. The input times of ROIs were compared between conventional manual method and this extraction module-assisted input method. The module for extracting ROI values operated successfully using the OCR and macro programs. The values of the area, average, standard deviation, maximum, and minimum could be recognized and error-corrected with AutoHotkey-coded module. The average input times using the conventional method and the proposed module-assisted method were 34.97 seconds and 7.87 seconds, respectively. A simple and efficient method for ROI value extraction was developed with open-source OCR and a macro program. Accurate inputs of various numbers from ROIs can be extracted with this module. The proposed module could be applied to the next generation of PACS or existing PACS that have not yet been upgraded. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  8. Radiation processes in astrophysics

    CERN Document Server

    Tucker, Wallace H

    1975-01-01

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

  9. Stellar Astrophysics with Arcus

    Science.gov (United States)

    Brickhouse, Nancy S.; Huenemoerder, David P.; Wolk, Scott; Schulz, Norbert; Foster, Adam; Brenneman, Laura; Poppenhaeger, Katja; Arcus Team

    2018-01-01

    The Arcus mission is now in Phase A of the NASA Medium-Class Explorer competition. We present here the Arcus science case for stellar astrophysics. With spectral resolving power of at least 2500 and effective area greater than 400 cm^2, Arcus will measure new diagnostic lines, e.g. for H- and He-like ions of oxygen and other elements. Weak dielectronic recombination lines will provide sensitive measurements of temperature to test stellar coronal heating models. Arcus will also resolve the coronal and accretion line components in young accreting stars, allowing detailed studies of accretion shocks and their post-shock behavior. Arcus can resolve line shapes and variability in hot star winds to study inhomogeneities and dynamics of wind structure. Such profiles will provide an independent measure of mass loss rates, for which theoretical and observational discrepancies can reach an order of magnitude. Arcus will also study exoplanet atmospheres through X-ray absorption, determing their extent and composition.

  10. Numerical relativity beyond astrophysics

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

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

  11. Basics of plasma astrophysics

    CERN Document Server

    Chiuderi, Claudio

    2015-01-01

    This book is an introduction to contemporary plasma physics that discusses the most relevant recent advances in the field and covers a careful choice of applications to various branches of astrophysics and space science. The purpose of the book is to allow the student to master the basic concepts of plasma physics and to bring him or her up to date in a number of relevant areas of current research. Topics covered include orbit theory, kinetic theory, fluid models, magnetohydrodynamics, MHD turbulence, instabilities, discontinuities, and magnetic reconnection. Some prior knowledge of classical physics is required, in particular fluid mechanics, statistical physics, and electrodynamics. The mathematical developments are self-contained and explicitly detailed in the text. A number of exercises are provided at the end of each chapter, together with suggestions and solutions.

  12. Numerical relativity beyond astrophysics.

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

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

  13. Theoretical Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Kamionkowski, Marc [Johns Hopkins Univ., Baltimore, MD (United States)

    2013-08-07

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

  14. 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

  15. Nuclear physics and astrophysics

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-09-01

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

  16. Development of a simple one-pot extraction method for various drugs and metabolites of forensic interest in blood by modifying the QuEChERS method.

    Science.gov (United States)

    Matsuta, Shuntaro; Nakanishi, Keiko; Miki, Akihiro; Zaitsu, Kei; Shima, Noriaki; Kamata, Tooru; Nishioka, Hiroshi; Katagi, Munehiro; Tatsuno, Michiaki; Tsuboi, Kento; Tsuchihashi, Hitoshi; Suzuki, Koichi

    2013-10-10

    A rapid and convenient extraction method has been developed for the determination of various drugs and metabolites of forensic interest in blood by modifying the dispersive solid-phase extraction method "QuEChERS". The following 13 analytes with various chemical properties were used for the method development and its validation: amphetamine, methamphetamine, zolpidem, the carboxylate-form major metabolite of zolpidem M-1, flunitrazepam, 7-aminoflunitrazepam, phenobarbital, triazolam, α-hydroxytriazolam, brotizolam, α-hydroxybrotizolam, chlorpromazine, and promethazine. The modification of the QuEChERS method includes the use of relatively large amounts of inorganic salts in order to coagulate blood, which allows easy isolation of the organic extract phase. A combination of 100 mg anhydrous magnesium sulfate as a dehydrating agent, 50mg sodium chloride as a salting-out agent, and 500 μL acetonitrile containing 0.2% acetic acid as the organic solvent provided the optimum conditions for processing a 100 μL whole blood sample. The recoveries of the analytes spiked into whole blood at 0.5 μg/mL ranged between 59% and 93%. Although the addition of the graphitized carbon Envi-carb for cleanup decreased the recoveries of zolpidem and its carboxylate-form metabolite M-1, it was very effective in avoiding interferences by cholesterol. The present method can provide a rapid, effective, user-friendly, and relatively hygienic method for the simultaneous extraction of a wide range of drugs and metabolites in whole blood specimens. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Millimeter and submillimeter wave spectroscopy: molecules of astrophysical interest

    International Nuclear Information System (INIS)

    Plummer, G.M.

    1985-01-01

    Species of three general types of molecular ions were studied by means of millimeter-submillimeter (mm/sub-mm) wave spectroscopy. Because of their highly reactive nature, it has been possible to study ionic species in the microwave region for only the past ten is presented here. A new method is presented here for production of such molecular ions in concentrations greater by one to two orders of magnitude than possible with previous techniques, and the subsequent first mm/sub/mm/ detections of two isotopic forms of HCO + , three isotopic forms of ArD + , and the molecular ion H 3 O + . Simple neutral species, which are generally less reactive than ions, are also present in relatively large concentrations in the interstellar medium and in the atmospheres of cool stars themselves. Presented here is the first laboratory microwave detection of two isotopic species of LiH 2 , a solid at normal temperatures and pressures. In addition, a combined analysis of these data, additional data collected on the related species LiD, and existing data on LiD is presented. Finally, a large fraction of the mm/sub/mm/ emissions observed toward the interstellar medium were shown to belong to a small number of relatively heavy, stable, but spectroscopically complicated molecules, many of them internal rotors

  18. High energy density laboratory astrophysics

    International Nuclear Information System (INIS)

    Remington, Bruce A

    2005-01-01

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

  19. 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

  20. Astrophysics for University Physics Courses: Wentzel's Method of Astrophysics Teaching

    Science.gov (United States)

    Zaratti, F.

    It is a crude but accepted truth that the current Physics student does not know the issues of modern Astronomy and Astrophysics. In the face of the difficulty to lecture a complete course of Astrophysics in standard university physics courses, the actual question, about how to introduce topics of astrophysics, is answered by Donat G. Wentzel (Emeritus Professor at Maryland University, College Park) using problems from Astrophysics to reinforce concepts from curricula courses and introduce modern research methods in those courses, taking advantage of the charm and the multi-disciplinarity of Astrophysics. Wentzel's method tries to teach Astrophysics as an application of standard courses, through a class-work and a co-operative effort of the all the classroom, emphasising, more than the mathematical solution, the context of the problem, the significant physics and the precision of the calculations. Wentzel's method is particularly appropriate for physics teaching in developing countries, where the access to the "frontier sciences" is difficult for most of students. Wentzel's booklet is essentially a guide for Physics teachers to a didactic application of his method. The booklet has been translated to Spanish and distributed in most of countries of Latin-America,. Wentzel's method has been applied in other areas, such as Atmospheric Physics in order to widen the horizon of students in modern Physics.

  1. Plasma physics of extreme astrophysical environments.

    Science.gov (United States)

    Uzdensky, Dmitri A; Rightley, Shane

    2014-03-01

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

  2. Transient Astrophysics Probe

    Science.gov (United States)

    Camp, Jordan; Transient Astrophysics Probe Team

    2018-01-01

    The Transient Astrophysics Probe (TAP) is a wide-field multi-wavelength transient mission proposed for flight starting in the late 2020s. The mission instruments include unique “Lobster-eye” imaging soft X-ray optics that allow a ~1600 deg2 FoV; a high sensitivity, 1 deg2 FoV soft X-ray telescope; a 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of 8 NaI gamma-ray detectors. TAP’s most exciting capability will be the observation of tens per year of X-ray and IR counterparts of GWs involving stellar mass black holes and neutron stars detected by LIGO/Virgo/KAGRA/LIGO-India, and possibly several per year X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays. TAP will also discover hundreds of X-ray transients related to compact objects, including tidal disruption events, supernova shock breakouts, and Gamma-Ray Bursts from the epoch of reionization.

  3. Atoms in astrophysics

    CERN Document Server

    Eissner, W; Hummer, D; Percival, I

    1983-01-01

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

  4. Nuclear physics and astrophysics

    International Nuclear Information System (INIS)

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

    1993-06-01

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

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

    Indian Academy of Sciences (India)

    Neutron stars involve extreme physics which is difficult (perhaps impossible) to explore in laboratory experiments. We have to turn to astrophysical observations, and try to extract information from the entire range of the electromagnetic spectrum. In addition, neutron stars may radiate gravitational waves through a range of ...

  6. 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.

  7. An introduction to astrophysical hydrodynamics

    CERN Document Server

    Shore, Steven N

    1992-01-01

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

  8. Neutrinos in astrophysics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Balantekin, A. B. [Physics Department, University of Wisconsin, Madison WI 53706 (United States)

    2016-06-21

    Neutrinos play a crucial role in many aspects of astrophysics and cosmology. Since they control the electron fraction, or equivalently neutron-to-proton ratio, neutrino properties impact yields of r-process nucleosynthesis. Similarly the weak decoupling temperature in the Big Bang Nucleosynthesis epoch is exponentially dependent on the neutron-to-proton ratio. In these conference proceedings, I briefly summarize some of the recent work exploring the role of neutrinos in astrophysics and cosmology.

  9. Nuclear level densities in astrophysics

    International Nuclear Information System (INIS)

    Woosley, S.E.

    1980-01-01

    The use of statistical nuclear level densities in astrophysics is briefly reviewed. Particular attention is given to the role of nuclear level density formulae in cross-section calculations for nucleosynthesis studies and to the effects of an assumed Fermi-gas model upon the properties of matter at very high temperature. The use of ν-strength functions in astrophysics is also briefly summarized

  10. Highlights of Spanish Astrophysics VII

    Science.gov (United States)

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

    2013-05-01

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

  11. 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…

  12. Astrophysical neutrinos and atmospheric leptons

    Directory of Open Access Journals (Sweden)

    Gaisser T.K.

    2017-01-01

    Full Text Available IceCube measurements of the neutrino flux from TeV to PeV show the signal of astrophysical neutrinos standing out at high energy well above the steeply falling foreground of atmospheric neutrinos. The astrophysical signal appears both in measurements of neutrino-induced muons and in the starting event sample, which responds preferentially to electron and tau neutrinos, but which also includes muon neutrinos. Searches for point sources of astrophysical neutrinos have, however, not yet identified a single source or class of sources for the astrophysical component. Some constraints on astrophysical sources implied by the current observations will be described in this talk. Uncertainties in the fluxes of atmospheric leptons resulting from an incomplete knowledge of the primary cosmic-ray spectrum and from a limited understanding of meson production, including charm will also be reviewed. The ultimate goal is to improve the understanding of the astrophysical spectrum in the transition to lower energy where atmospheric neutrinos dominate. The main aspects of this presentation will be included in the author's Review Talk at the end of the Symposium.

  13. Gravitational waves: A challenge to theoretical astrophysics

    International Nuclear Information System (INIS)

    Ferrari, V.; Miller, J.C.; Rezzolla, L.

    2001-01-01

    During the 20th century, new windows on the Universe have been opened by the advent of radio astronomy and X-ray astronomy and these, together with the great advances in optical astronomy (both from the Earth's surface and from space), have revolutionized our understanding of the Universe and the way in which it works. Now, as we enter the twenty-first century, we await the opening of another new window - that provided by gravitational waves - which will allow us a closer 'view' of black holes and neutron stars, as well as providing a new probe of processes in the very early Universe. This is an exciting prospect but one which poses a serious challenge to theoretical astrophysics. The new generation of detectors (both laser interferometers and resonant detectors) require input from theoreticians regarding the possible mechanisms for generation of gravitational waves by astronomical sources and predictions of the waveforms produced. This input is essential in order both to tune the parameters of the detectors and to provide templates for use in extracting the tiny gravitational-wave signals from the ambient noise. Also, we need to understand how gravitational wave data, when it arrives, could be used in order to obtain information about the nature of the sources and about their dynamical evolution as well as, perhaps, giving deeper insights into some questions of fundamental physics by means of probing the state of matter under the extreme conditions of energy and pressure found in the interior of neutron stars and in the very early universe. This can provide opportunities beyond the capabilities of experiments carried out in terrestrial laboratories. For a week at the beginning of June 2000, 106 scientists from 28 countries came to Trieste for a meeting whose aim was to present a survey of the current status of the response of theoreticians to the challenge described above, as well as including progress reports on the different types of detector. The meeting was a

  14. Relativistic Astrophysics and Cosmology: A Primer

    International Nuclear Information System (INIS)

    Abramowicz, Marek A

    2007-01-01

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

  15. High energy astrophysics. An introduction

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

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

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing ...

  17. Spin light of neutrino in astrophysical environments

    Science.gov (United States)

    Grigoriev, Alexander; Lokhov, Alexey; Studenikin, Alexander; Ternov, Alexei

    2017-11-01

    The spin light of neutrino (SLν) is a new possible mechanism of electromagnetic radiation by a massive neutrino (with a nonzero magnetic moment) moving in media. Since the prediction of this mechanism, the question has been debated in a number of publications as whether the effect can be of any significance for realistic astrophysical conditions. Although this effect is strongly suppressed due to smallness of neutrino magnetic moment, for ultra-high energy neutrinos (PeV neutrinos recently observed by the IceCube collaboration, for instance) the SLν might be of interest in the case of neutrinos propagating in dense matter. An advanced view on the SLν in matter is given, and several astrophysical settings (a neutron star, supernova, Gamma-Ray Burst (GRB), and relic neutrino background) for which the effect can be realized are considered. Taking into account the threshold condition and also several competing processes, we determine conditions for which the SLν mechanism is possible. We conclude that the most favorable case of the effect manifestation is provided by ultra dense matter of neutron stars and ultrahigh energy of the radiating neutrino, and note that these conditions can be met within galaxy clusters. It is also shown that due to the SLν specific polarization properties this electromagnetic mechanism is of interest in the connection with the observed polarization of GRB emission.

  18. 360-degree videos: a new visualization technique for astrophysical simulations

    Science.gov (United States)

    Russell, Christopher M. P.

    2017-11-01

    360-degree videos are a new type of movie that renders over all 4π steradian. Video sharing sites such as YouTube now allow this unique content to be shared via virtual reality (VR) goggles, hand-held smartphones/tablets, and computers. Creating 360° videos from astrophysical simulations is not only a new way to view these simulations as you are immersed in them, but is also a way to create engaging content for outreach to the public. We present what we believe is the first 360° video of an astrophysical simulation: a hydrodynamics calculation of the central parsec of the Galactic centre. We also describe how to create such movies, and briefly comment on what new science can be extracted from astrophysical simulations using 360° videos.

  19. BOOK REVIEW: Astrophysics (Advanced Physics Readers)

    Science.gov (United States)

    Kibble, Bob

    2000-07-01

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

  20. Astrophysics and the evolution of the universe

    CERN Document Server

    Kisslinger, Leonard S

    2014-01-01

    The aim of this book is to teach undergraduate college or university students the basic physics concepts needed to understand the mathematics which describes the evolution of the universe, and based on this to teach the astrophysical theories behind evolution from very early times to the present. The book does not require students to have extensive knowledge of mathematics, like calculus, and includes material that explains concepts such as velocity, acceleration, and force. Based on this, fascinating topics such as Dark Matter, measuring Dark Energy via supernovae velocities, and the creation of mass via the Higgs mechanism are explained. All college students with an interest in science, especially astronomy, without extensive mathematical backgrounds should be able to use and learn from this book. Adults interested in topics like dark energy and the Higgs boson, which are in the news, can make use of this book as well.

  1. Nuclear Astrophysics Experiments at CIAE

    Energy Technology Data Exchange (ETDEWEB)

    Liu Weiping [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China)]. E-mail: wpliu@iris.ciae.ac.cn; Li Zhihong [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Bai Xixiang [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Lian Gang [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Guo Bing [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Zeng, Sheng [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Yan Shengquan [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Wang Baoxiang [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Shu Nengchuan [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Wu Kaisu [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China); Chen Yongshou [China Institute of Atomic Energy, P.O. Box 275(80), Beijing 102413 (China)

    2005-07-25

    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 {sup 7}Be(d, n){sup 8}B, {sup 11}C(d, n){sup 12}N, {sup 8}Li(d, n){sup 9}Be and {sup 8}Li(d, p){sup 9}Li in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of {sup 7}Be(p, {gamma}){sup 8}B,{sup 11}C(p, {gamma}){sup 12}N, {sup 8}Li(n, {gamma}){sup 9}Li at astrophysically relevant energies.

  2. 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...

  3. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1966-01-01

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

  4. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1963-01-01

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

  5. 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.

  6. Nuclear astrophysics away from stability

    International Nuclear Information System (INIS)

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

    1985-08-01

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

  7. Survey of Introductory Astrophysics Textbooks

    Science.gov (United States)

    Bruning, David

    Although Bruning has produced a series of textbook surveys for introductory astronomy for non science majors, the present survey is the first to examine introductory astrophysics books intended for astronomy majors. It provides information about 21 introductory astrophysics textbooks: nine broad topic texts, two on techniques, three on the Solar System, one on galaxies and cosmology, and six on stars. A set of seven tables indicates prices, page counts by topics, pedagogical features of the text, appendixes, and text Web sites to help instructors narrow the list of textbooks for closer inspection as they make adoption decisions.

  8. Nuclear astrophysics data at ORNL

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  9. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1968-01-01

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

  10. Astrophysical Model Selection in Gravitational Wave Astronomy

    Science.gov (United States)

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

    2012-01-01

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

  11. VI European Summer School on Experimental Nuclear Astrophysics

    Science.gov (United States)

    The European Summer School on Experimental Nuclear Astrophysics has reached the sixth edition, marking the tenth year's anniversary. The spirit of the school is to provide a very important occasion for a deep education of young researchers about the main topics of experimental nuclear astrophysics. Moreover, it should be regarded as a forum for the discussion of the last-decade research activity. Lectures are focused on various aspects of primordial and stellar nucleosynthesis, including novel experimental approaches and detectors, indirect methods and radioactive ion beams. Moreover, in order to give a wide educational offer, some lectures cover complementary subjects of nuclear astrophysics such as gamma ray astronomy, neutron-induced reactions, short-lived radionuclides, weak interaction and cutting-edge facilities used to investigate nuclear reactions of interest for astrophysics. Large room is also given to young researcher oral contributions. Traditionally, particular attention is devoted to the participation of students from less-favoured countries, especially from the southern coast of the Mediterranean Sea. The school is organised by the Catania Nuclear Astrophysics research group with the collaboration of Dipartimento di Fisica e Astromomia - Università di Catania and Laboratori Nazionali del Sud - Istituto Nazionale di Fisica Nucleare.

  12. Compressed Baryonic Matter of Astrophysics

    OpenAIRE

    Guo, Yanjun; Xu, Renxin

    2013-01-01

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

  13. Astrophysics at very high energies

    International Nuclear Information System (INIS)

    Aharonian, Felix; Bergstroem, Lars; Dermer, Charles

    2013-01-01

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

  14. Electric Currents along Astrophysical Jets

    Directory of Open Access Journals (Sweden)

    Ioannis Contopoulos

    2017-10-01

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

  15. Astronomy & Astrophysics: an international journal

    Science.gov (United States)

    Bertout, C.

    2011-07-01

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

  16. 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…

  17. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

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

  18. Indirect methods in nuclear astrophysics

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  19. 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.)

  20. Two families of astrophysical diverging lens models

    Science.gov (United States)

    Er, Xinzhong; Rogers, Adam

    2018-03-01

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

  1. High-Energy Spectroscopic Astrophysics Swiss Society for Astrophysics and Astronomy

    CERN Document Server

    Kahn, Steven M; von Ballmoos, Peter

    2005-01-01

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

  2. 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

  3. Coulomb breakup of nuclei-applications to astrophysics

    International Nuclear Information System (INIS)

    Baur, G.; Rebel, H.

    1996-04-01

    The Coulomb dissociation process, induced by the intense source of quasi-real photons acting as nuclear particles passing the field of a heavy nucleus, has attracted a great deal of attention. As specific application and access to information to the time-reversed radiative capture reactions of astrophysical interest at stellar energies, it provides several advantages based on larger cross sections and on the flexibilities of the breakup kinematics. Difficulties in the analysis arise from possible interference of nuclear interactions and final state effects through multiphoton exchange (post acceleration) which need careful consideration. Since the introduction of this novel approach as tool of nuclear astrophysics, a number of theoretical and experimental investigations have been performed, with interesting new information and results which provide an improved and detailed understanding of the experimental conditions and of the theoretical basis of the method. The progress in experiment and theory is reviewed, and various cases of actual interest and current applications are discussed. (orig.)

  4. A laser application to nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX (United States); Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX 78712 (United States); Bonasera, A. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX, U.S.A. and INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Kimura, S. [Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Mazzocco, M. [Dipartimento di Fisica e Astronomia Università degli Studi di Padova and INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Consoli, F.; De Angelis, R.; Andreoli, P. [Associazione Euratom-ENEA Sulla Fusione, Via Enrico Fermi 45, CP 65-00044 Frascati, Rome (Italy); Ditmire, T. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX, 78712 (United States)

    2014-05-09

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

  5. A laser application to nuclear astrophysics

    Science.gov (United States)

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

    2014-05-01

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

  6. The Explorer program for astronomy and astrophysics

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  7. Nuclear astrophysics of supernovae

    International Nuclear Information System (INIS)

    Cooperstein, J.

    1988-01-01

    In this paper, I'll give a general introduction to Supernova Theory, beginning with the presupernova evolution and ending with the later stages of the explosion. This will be distilled from a colloquium type of talk. It is necessary to have the whole supernova picture in one's mind's eye when diving into some of its nooks and crannies, as it is quite a mess of contradictory ingredients. We will have some discussion of supernova 1987a, but will keep our discussion more general. Second, we'll look at the infall and bounce of the star, seeing why it goes unstable, what dynamics it follows as it collapses, and how and why it bounces back. From there, we will go on to look at the equation of state (EOS) in more detail. We'll consider the cases T = 0 and T > 0. We'll focus on /rho/ 0 , and then /rho/ > /rho/ 0 and the EOS of neutron stars, and whether or not they contain cores of strange matter. There are many things we could discuss here and not enough time. If I had more lectures, the remaining time would focus on two more questions of special interest to nuclear physicists: the electron capture reactions and neutrino transport. If time permitted, we'd have some discussion of the nucleosynthetic reactions in the explosion's debris as well. However, we cannot cover such material adequately, and I have chosen these topics because they are analytically tractable, pedagogically useful, and rather important. 23 refs., 14 figs., 3 tabs

  8. TESS Objects of Interest

    Science.gov (United States)

    Guerrero, Natalia; Glidden, Ana; Fausnaugh, Michael; TESS Team

    2018-01-01

    We describe the search for TESS Objects of Interest (TOIs), led by the MIT branch of the TESS Science Office (TSO). TSO has developed a tool called TESS Exoplanet Vetter (TEV) to facilitate this process. Individuals independently examine data validation products for each target and assign a category to the object: planet candidate, eclipsing binary, other astrophysical, stellar variability, or instrument noise/systematic. TEV assigns a preliminary follow-up priority designation to each object and allows for modification when final dispositions are decided on in a group setting. When all targets are vetted, TEV exports a catalogue of TOIs which is delivered to the TESS Follow-Up Observing Program (TFOP), working with ExoFOP-TESS, and made publicly available on the official TESS website and the Mikulski Archive for Space Telescopes (MAST).

  9. Some nuclear data needs in astrophysics

    International Nuclear Information System (INIS)

    Mathews, G.J.; Bauer, R.W.; Bloom, S.D.; Haight, R.C.; Howard, W.M.; Takahashi, K.; Ward, R.A.

    1985-05-01

    In this paper we discuss a number of astrophysical environments and how improved nuclear data could facilitate a better understanding of them. One area of interest includes proton and alpha-particle reactions with unstable nuclei which are necessary for understanding the nucleosynthesis and energy generation in hot hydrogen-burning environments. Efforts underway at LLNL and elsewhere to develop the technology for the measurement of these reaction rates are discussed. Heavy-element nucleosynthesis in the late stages of red-giant stars and supernovae requires a complete network of neutron capture rates and beta-decay rates for nuclei near and far from stability. Experimental and theoretical efforts at LLNL to supply the input data and to model the nucleosynthetic environments will be outlined. Suggestions are made as to which nuclear data are most critical for the various scenarios. 42 refs., 11 figs., 1 tab

  10. Few-body models for nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Descouvemont, P., E-mail: pdesc@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Quantique, C.P. 165/82, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Suzuki, Y., E-mail: suzuki@nt.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); RIKEN Nishina Center, Wako 351-0198 (Japan); Aoyama, S., E-mail: aoyama@cc.niigata-u.ac.jp [Center for Academic Information Service, Niigata University, Niigata 950-2181 (Japan); Arai, K., E-mail: arai@nagaoka-ct.ac.jp [Division of General Education, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, Niigata 940-8532 (Japan)

    2014-04-15

    We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the {sup 2}H(d, γ){sup 4}He, {sup 2}H(d, p){sup 3}H and {sup 2}H(d, n){sup 3}He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.

  11. Fermi acceleration in astrophysical jets

    OpenAIRE

    Rieger, Frank M.; Bosch-Ramon, Valenti; Duffy, Peter

    2006-01-01

    We consider the acceleration of energetic particles by Fermi processes (i.e., diffusive shock acceleration, second order Fermi acceleration, and gradual shear acceleration) in relativistic astrophysical jets, with particular attention given to recent progress in the field of viscous shear acceleration. We analyze the associated acceleration timescales and the resulting particle distributions, and discuss the relevance of these processes for the acceleration of charged particles in the jets of...

  12. Multifragmentation model for astrophysical strangelets

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  13. High energy astrophysics an introduction

    CERN Document Server

    Courvoisier, Thierry J -L

    2013-01-01

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

  14. Relativistic Astrophysics and Cosmology: A Primer

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, Marek A [Department of Astronomy and Astrophysics, Chalmers University of Technology, 41296 Goeteborg (Sweden)

    2007-10-21

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

  15. Control of microorganisms of oral health interest with Arctium lappa L. (burdock) extract non-cytotoxic to cell culture of macrophages (RAW 264.7).

    Science.gov (United States)

    de Oliveira, Jonatas Rafael; de Aguiar Almeida, Rosilene Batista; das Graças Figueiredo Vilela, Polyana; de Oliveira, Felipe Eduardo; da Rocha, Rosilene Fernandes; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

    2014-08-01

    To evaluate the antimicrobial activity of Arctium lappa L. extract on Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Candida albicans, C. tropicalis and C. glabrata. In addition, the cytotoxicity of this extract was analyzed on macrophages (RAW 264.7). By broth microdilution method, different concentrations of the extract (250-0.4 mg/mL) were used in order to determine the minimum microbicidal concentration (MMC) in planktonic cultures and the most effective concentration was used on biofilms on discs made of acrylic resin. The cytotoxicity A. lappa L. extract MMC was evaluated on RAW 264.7 by MTT assay and the quantification of IL-1β and TNF-α by ELISA. The most effective concentration was 250 mg/mL and also promoted significant reduction (log₁₀) in the biofilms of S. aureus (0.438 ± 0.269), S. epidermidis (0.377 ± 0.298), S. mutans (0.244 ± 0.161) and C. albicans (0.746 ± 0.209). Cell viability was similar to 100%. The production of IL-1β was similar to the control group (p>0.05) and there was inhibition of TNF-α (plappa L. extract was microbicidal for all the evaluated strains in planktonic cultures, microbiostatic for biofilms and not cytotoxic to the macrophages. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. In situ genomic DNA extraction for PCR analysis of regions of interest in four plant species and one filamentous fungi

    OpenAIRE

    Luis E. Rojas; Maritza Reyes; Naivy Pérez-Alonso; María I. Olóriz; Laisyn Posada-Pérez; Bárbara Ocaña; Orelvis Portal; Borys Chong-Pérez; Jorge L. Pérez Pérez

    2014-01-01

    The extraction methods of genomic DNA are usually laborious and hazardous to human health and the environment by the use of organic solvents (chloroform and phenol). In this work a protocol for in situ extraction of genomic DNA by alkaline lysis is validated. It was used in order to amplify regions of DNA in four species of plants and fungi by polymerase chain reaction (PCR). From plant material of Saccharum officinarum L., Carica papaya L. and Digitalis purpurea L. it was possible to extend ...

  17. Cosmological and astrophysical implications of sterile neutrinos

    Science.gov (United States)

    Petraki, Kalliopi

    The discovery of neutrino masses suggests that the Standard Model should be supplemented with new gauge-singlet fermions, often called sterile neutrinos. The interplay among the new couplings introduced in the Standard Model can accommodate the neutrino oscillation data for a variety of choices: the new particles can be extremely heavy and practically unobservable, or they can be light, in which case they can solve several long-standing puzzles. It has been shown, for example, that sterile neutrinos in some range of masses can account for dark matter, their emission from a supernova can explain pulsar kicks, arid their decays can play an important role in the formation of the first stars. Though indirect, these clues indicate that sterile neutrinos can be the minimal solution to a variety of unsolved problems. This emphasizes the importance of investigating further the consequences of these new degrees of freedom for cosmology and astrophysics. In this dissertation, I explore the possible role of sterile neutrinos of different mass scales in some cosmological and astrophysical phenomena. A minimal extension of the Higgs sector of the Standard Model, with a gauge- singlet boson coupled to sterile neutrinos, can provide a consistent framework for the theory of neutrino masses, and can produce a relic population of keV sterile neutrinos via decays of the singlet Higgs. The latter can account for the dark matter of the universe. The mechanism operates around the electroweak scale, and has interesting consequences for the electroweak phase transition. Relic sterile neutrinos produced via decays at the electroweak scale constitute colder dark matter than those produced via other previously suggested mechanisms. The primordial thermal content of dark matter has important implications for the formation of cosmic structures, such as clusters and galaxies. The assessment of the relevant properties suggests that sterile neutrinos produced at the electroweak scale are a

  18. Interesting Behavior of Pachycormus discolor Leaves Ethanol Extract as a Corrosion Inhibitor of Carbon Steel in 1 M HCl: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Ramses Garcia Inzunza

    2012-01-01

    Full Text Available The purpose of this paper is to evaluate the inhibitive action of an ethanol extract from the leaves of Pachycormus discolor (EEPD on the corrosion of carbon steel in 1 M HCl at different temperatures; gravimetric method and electrochemical tests were conducted. Potentiodynamic polarization was used at room temperature and resistance polarization at different temperatures. Thermodynamic adsorption parameters are shown in order to demonstrate the spontaneous adsorption. The inhibition of EEPD was performed via adsorption of the extract species on the carbon steel surface. The ethanol extract obeys Langmuir adsorption isotherm. Potentiodynamic polarization results indicate that the ethanol extract acts as a mixed type inhibitor. The results revealed that the inhibition efficiency (IE of EEPD increases (when the concentration is increased. Phytochemical and FTIR analyses are also presented in this work. It was found that the IE increases with the temperature in a 2.0% v/v solution which showed 94.52% IE at 25∘C and 97.89% at 75∘C.

  19. Astrophysical probes of dark matter

    Science.gov (United States)

    Hurst, Travis J.

    In the ACDM model,≈ 26% of the matter-energy content of the Universe is in the form of an unidentified Cold Dark Matter. Observations indicate that the Dark Matter is a new exotic particle not accounted for in the Standard Model of particle physics. Identifying the Dark Matter particle is one of the most pressing problems in cosmology and particle physics. In this thesis we investigate several possible astrophysical signatures of Dark Matter: Dark Matter annihilations in cold White Dwarfs provide a source of luminosity that could halt their cooling. This effect can be used to constrain the Dark Matter density local to the White Dwarf. In the case of the coldest White Dwarf in a Globular Cluster, a constraint on the maximum Dark Matter content is derived. Globular Clusters do not appear to have Dark Matter halos today, but could have possessed them in the past. We investigate whether Globular Clusters could have lost their halos through multi-body gravitational interactions--we find that this scenario is unlikely. Finally, we explore the effects of Asymmetric Dark Matter on stellar evolution. Asymmetric Dark Matter can alter the transport of energy in the cores of stars. We show that this has potentially observable effects on low mass Main Sequence and post-Main Sequence stars. Our main conclusion is that astrophysical observations can potentially rule out some Dark Matter models. On the other hand, if the properties of the Dark Matter particle become known, then its astrophysical effects must be taken into account when evaluating observations.

  20. Underground Nuclear Astrophysics in China

    Science.gov (United States)

    Liu, Weiping

    2016-10-01

    Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors will be set up. We plan to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies, such as 25Mg(p,γ)26Al, 19F(p,α)16O, 13C(α,n)16O and 12C(α,γ)16O.

  1. Astrophysics and Cosmology: International Partnerships

    Science.gov (United States)

    Blandford, Roger

    2016-03-01

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

  2. Dark matter: the astrophysical case

    International Nuclear Information System (INIS)

    Silk, J.

    2012-01-01

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

  3. Nuclear physics in astrophysics. Part 2. Abstracts

    International Nuclear Information System (INIS)

    Gyuerky, Gy.; Fueloep, Zs.

    2005-01-01

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

  4. Astrophysical Observations: Lensing and Eclipsing Einstein's Theories

    OpenAIRE

    Bennett, Charles L.

    2005-01-01

    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 Ein...

  5. High Energy Astrophysics Science Archive Research Center

    Data.gov (United States)

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

  6. 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.

  7. 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...

  8. Astrophysics with small satellites in Scandinavia

    DEFF Research Database (Denmark)

    Lund, Niels

    2003-01-01

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

  9. Demographics in Astronomy and Astrophysics

    Science.gov (United States)

    Ulvestad, James S.

    2011-05-01

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

  10. Focusing telescopes in nuclear astrophysics

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  11. Focusing telescopes in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  12. A Review of Astrophysical Jets

    Directory of Open Access Journals (Sweden)

    James H. Beall

    2014-12-01

    Full Text Available Astrophysical jets are ubiquitous: this simple statement has become a commonplace over the last three decades and more as a result of observing campaigns using detectors sensitive from radio to gamma-ray energies. During this epoch, theoretical models of these sources have become more complex, moving from assumptions of isotropy that made analytic calculations possible, to fully anisotropic models of emission from the jets and their interactions with the interstellar and intra-cluster medium. Such calculations are only possible because we have extensive computational resources. In addition, the degree of international cooperation required for observing campaigns of these sorts is remarkable, since the instruments include among others the Very Large Array (VLA, the Very Long Baseline Array (VLBA, and entire constellations of satellite instruments, often working in concert. In this paper, I discuss some relevant observations from these eorts and the theoretical interpretations they have occasioned.

  13. 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.

  14. Tests on measuring astrophysical S-factors with transfer reactions

    CERN Document Server

    Crespo, R

    2002-01-01

    We propose a general method to test the uniqueness property of the Asymptotic Normalization Constant, ANC. We apply this method for the case of the vertex sup 1 sup 0 B -> sup 9 Be+p using a set of different proton-transfer reactions at different energies. Given the limited sets of data for peripheral transfer reactions, we underline the present difficulties in extracting astrophysical S-factors and point out the inadequacy of some of the available data. Finally, we make some suggestions for future experiments in order to make this test conclusive.

  15. 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.

  16. Astrophysical targets of the Fresnel diffractive imager

    Science.gov (United States)

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

    2017-11-01

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

  17. Studying Nuclear Astrophysics at NIF

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, R; Bernstein, L; Brune, C

    2009-07-01

    The National Ignition Facility's primary goal is to generate fusion energy. But the starlike conditions that it creates will also enable NIF scientists to study astrophysically important nuclear reactions. When scientists at the stadium-sized National Ignition Facility attempt to initiate fusion next year, 192 powerful lasers will direct 1.2 MJ of light energy toward a two-mm-diameter pellet of deuterium ({sup 2}H, or D) and tritium ({sup 3}H, or T). Some of that material will be gaseous, but most will be in a frozen shell. The idea is to initiate 'inertial confinement fusion', in which the two hydrogen isotopes fuse to produce helium-4, a neutron, and 17.6 MeV of energy. The light energy will be delivered to the inside walls of a hohlraum, a heavy-metal, centimeter-sized cylinder that houses the pellet. The container's heated walls will produce x rays that impinge on the pellet and ablate its outer surface. The exiting particles push inward on the pellet and compresses the DT fuel. Ultimately a hot spot develops at the pellet's center, where fusion produces {sup 4}He nuclei that have sufficient energy to propagate outward, trigger successive reactions, and finally react the frozen shell. Ignition should last several tens of picoseconds and generate more than 10 MJ of energy and roughly 10{sup 19} neutrons. The temperature will exceed 10{sup 8} K and fuel will be compressed to a density of several hundred g/cm{sup 3}, both considerably greater than at the center of the Sun. The figure shows a cutaway view of NIF. The extreme conditions that will be produced there simulate those in nuclear weapons and inside stars. For that reason, the facility is an important part of the US stockpile stewardship program, designed to assess the nation's aging nuclear stockpile without doing nuclear tests. In this Quick Study we consider a third application of NIF - using the extraordinary conditions it will produce to perform experiments in basic

  18. 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

  19. Scaling Extreme Astrophysical Phenomena to the Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Remington, B A

    2007-11-01

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

  20. Advanced Data Visualization in Astrophysics: The X3D Pathway

    Science.gov (United States)

    Vogt, Frédéric P. A.; Owen, Chris I.; Verdes-Montenegro, Lourdes; Borthakur, Sanchayeeta

    2016-02-01

    Most modern astrophysical data sets are multi-dimensional; a characteristic that can nowadays generally be conserved and exploited scientifically during the data reduction/simulation and analysis cascades. However, the same multi-dimensional data sets are systematically cropped, sliced, and/or projected to printable two-dimensional diagrams at the publication stage. In this article, we introduce the concept of the “X3D pathway” as a mean of simplifying and easing the access to data visualization and publication via three-dimensional (3D) diagrams. The X3D pathway exploits the facts that (1) the X3D 3D file format lies at the center of a product tree that includes interactive HTML documents, 3D printing, and high-end animations, and (2) all high-impact-factor and peer-reviewed journals in astrophysics are now published (some exclusively) online. We argue that the X3D standard is an ideal vector for sharing multi-dimensional data sets because it provides direct access to a range of different data visualization techniques, is fully open source, and is a well-defined standard from the International Organization for Standardization. Unlike other earlier propositions to publish multi-dimensional data sets via 3D diagrams, the X3D pathway is not tied to specific software (prone to rapid and unexpected evolution), but instead is compatible with a range of open-source software already in use by our community. The interactive HTML branch of the X3D pathway is also actively supported by leading peer-reviewed journals in the field of astrophysics. Finally, this article provides interested readers with a detailed set of practical astrophysical examples designed to act as a stepping stone toward the implementation of the X3D pathway for any other data set.

  1. Multiscale Modeling of Astrophysical Jets

    Directory of Open Access Journals (Sweden)

    James H. Beall

    2014-12-01

    Full Text Available We are developing the capability for a multi-scale code to model the energy deposition rate and momentum transfer rate of an astrophysical jet which generates strong plasma turbulence in its interaction with the ambient medium through which it propagates. We start with a highly parallelized version of the VH-1 Hydrodynamics Code (Coella and Wood 1984, and Saxton et al., 2005. We are also considering the PLUTO code (Mignone et al. 2007 to model the jet in the magnetohydrodynamic (MHD and relativistic, magnetohydrodynamic (RMHD regimes. Particle-in-Cell approaches are also being used to benchmark a wave-population models of the two-stream instability and associated plasma processes in order to determine energy deposition and momentum transfer rates for these modes of jet-ambient medium interactions. We show some elements of the modeling of these jets in this paper, including energy loss and heating via plasma processes, and large scale hydrodynamic and relativistic hydrodynamic simulations. A preliminary simulation of a jet from the galactic center region is used to lend credence to the jet as the source of the so-called the Fermi Bubble (see, e.g., Su, M. & Finkbeiner, D. P., 2012*It is with great sorrow that we acknowledge the loss of our colleague and friend of more than thirty years, Dr. John Ural Guillory, to his battle with cancer.

  2. Transport processes in space physics and astrophysics

    CERN Document Server

    Zank, Gary P

    2014-01-01

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

  3. Astrophysics implication of dense matter phase diagram

    International Nuclear Information System (INIS)

    Sedrakian, A.

    2010-01-01

    I will discuss the ways that astrophysics can help us to understand the phase diagram of dense matter. The examples will include gravitational wave from compact stars, cooling of compact stars, and effects on vorticity on compact star dynamics. (author)

  4. Cosmological and astrophysical neutrino mass measurements

    DEFF Research Database (Denmark)

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

    2011-01-01

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

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

    Indian Academy of Sciences (India)

    Editorial Board. Journal of Astrophysics and Astronomy. Chief Editor. Ram Sagar, Indian Institute of Astrophysics, Bengaluru. Associate Editor. Annapurni Subramaniam, Indian Institute of Astrophysics, Bengaluru T.P. Prabhu, Indian Institute of Astrophysics, Bengaluru. Editorial Board. P. Ajith, International Center for ...

  6. Two LANL laboratory astrophysics experiments

    Science.gov (United States)

    Intrator, Thomas; Weber, Thomas; Feng, Yan; Hutchinson, Trevor; Dunn, John; Akcay, Cihan

    2014-06-01

    Two laboratory experiments are described that have been built at Los Alamos (LANL) to gain access to a wide range of fundamental plasma physics issues germane to astro, space, and fusion plasmas. The over arching theme is magnetized plasma dynamics which includes significant currents, MHD forces and instabilities, magnetic field creation and annihilation, sheared flows and shocks. The Relaxation Scaling Experiment (RSX) creates current sheets and flux ropes that exhibit fully 3D dynamics, and can kink, bounce, merge and reconnect, shred, and reform in complicated ways. Recent movies from a large data set describe the 3D magnetic structure of a driven and dissipative single flux rope that spontaneously self saturates a kink instability. Examples of a coherent shear flow dynamo driven by colliding flux ropes will also be shown.The Magnetized Shock Experiment (MSX) uses Field reversed configuration (FRC) experimental hardware that forms and ejects FRCs at 150km/sec. This is sufficient to drive a collision less magnetized shock when stagnated into a mirror stopping field region with Alfven Mach number MA=3 so that super critical shocks can be studied. We are building a plasmoid accelerator to drive Mach numbers MA >> 3 to access solar wind and more exotic astrophysical regimes. Unique features of this experiment include access to parallel, oblique and perpendicular shocks, shock region much larger than ion gyro radii and ion inertial length, room for turbulence, and large magnetic and fluid Reynolds numbers.*DOE Office of Fusion Energy Sciences under LANS contract DE-AC52-06NA25396, NASA Geospace NNHIOA044I, Basic, Center for Magnetic Self Organization

  7. Nuclear astrophysics: a new era

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-02-01

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

  8. Distance Measurement Solves Astrophysical Mysteries

    Science.gov (United States)

    2003-08-01

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

  9. Photo and thermochemical evolution of astrophysical ice analogues as a source for soluble and insoluble organic materials in Solar system minor bodies

    Science.gov (United States)

    de Marcellus, Pierre; Fresneau, Aurelien; Brunetto, Rosario; Danger, Gregoire; Duvernay, Fabrice; Meinert, Cornelia; Meierhenrich, Uwe J.; Borondics, Ferenc; Chiavassa, Thierry; Le Sergeant d'Hendecourt, Louis

    2017-01-01

    Soluble and insoluble organic matter (IOM) is a key feature of primitive carbonaceous chondrites. We observe the formation of organic materials in the photothermochemical treatment of astrophysical ices in the laboratory. Starting from a low vacuum ultraviolet (VUV) irradiation dose on templates of astrophysical ices at 77 K, we obtain first a totally soluble form of organic matter at room temperature. Once this organic residue is formed, irradiating it further in vacuum results in the production of a thin altered dark crust on top of the initial soluble one. The whole residue is studied here by non-destructive methods inducing no alteration of samples, visible microscopy and mid-infrared (micro-)spectroscopy. After water extraction of the soluble part, an insoluble fraction remains on the sample holder which provides a largely different infrared spectrum when compared to the one of the soluble sample. Therefore, from the same VUV and thermal processing of initial simple ices, we produce first a soluble material from which a much larger irradiation dose leads to an insoluble one. Interestingly, this insoluble fraction shows some spectral similarities with natural samples of IOM extracted from two meteorites (Tagish Lake and Murchison), selected as examples of primitive materials. It suggests that the organic molecular diversity observed in meteorites may partly originate from the photo and thermal processing of interstellar/circum-stellar ices at the final stages of molecular cloud evolution towards the build-up of our Solar system.

  10. Journal of Astrophysics and Astronomy

    Indian Academy of Sciences (India)

    58

    learning is analyzed by Liu and Song (Liu et al 2015), in which Modified Discriminant Analysis based on Fisher Criterion and Manifold Learning (MDA) is proposed to feature extraction, and then the traditional classifier SVM is used to classify the stellar spectra. The above classification method uses the similar concepts with ...

  11. Dust Growth in Astrophysical Plasmas

    Science.gov (United States)

    Bingham, R.; Tsytovich, V. N.

    2002-12-01

    Dust formation in space is important in diverse environments such as dust molecular clouds, proto-planetary nebulae, stellar outbursts, and supernova explosions. The formation of dust proceeds the formation of stellar objects and planets. In all these environments the dust particles interact with both neutral and plasma particles as well as with (ultraviolet) radiation and cosmic rays. The conventional view of grain growth is one based on accretion by the Van der Waals and chemical forces [Watson and Salpeter [14] considered in detail both theoretically and numerically (Kempf at all [6],Meaking [7]( and confirmed recently by micro-gravity experiments Blum et all [2]). The usual point of view is that the dust grow is occurring in dust molecular clouds at very low temperatures ~ (10 - 30)° K and is a slow process - dust grows to a size of about 0.1 μm in 106 - 109 years. This contradicts recent observations of dust growing in winds of C-stars in about 10 years and behind the supernova SN1987A shock in about 500 days. Also recent observation of star formation at the edge of irradiated dust clouds suggests that new plasma mechanism operates in star formation. Dusty plasma mechanisms of agglomeration are analyzed as an explanation of the new astrophysical observation. New micro-gravity experiments are proposed for observing the plasma mechanisms of dust agglomeration at gas pressures substantially higher than used in ([2]. Calculations for the growth rates of dust agglomeration due to plasma mechanisms are presented. It is shown that at large neutral gas densities the dust plasma attraction provides an explanation of dust grow in about 10 days observed in H-star winds. Ionization by cosmic rays and by radioactive dust can provide the dust attraction necessary for forming dust clumping observed in molecular clouds and the fractal plasma clumping can enhance the time to reach the gravitational contraction phase operating at the final stage of star formation. A new

  12. 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.

  13. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

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

  14. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  15. Flexible, mastery-oriented astrophysics sequence

    Science.gov (United States)

    Zeilik, Michael

    1981-09-01

    This paper reports on the implementation and impact of a two-semester mastery-oriented astrophysics sequence for upper-level physics-astrophysics majors designed to handle flexibly a wide range of student backgrounds. A Personalized System of Instruction (PSI) format was used, which facilitated frequent student-instructor interaction and role-modelpan>ing behavior in class. Compared to students' reactions to the same content in a lecture format, students reported the mastery-oriented courses as helping them better to develop professional skills, competencies, and points of view; learn how professionals gain new knowledge in astrophysics; develop skills in oral and written expression; and learn fundamental principles and theories. These attitudes held up over three years of course development and evaluation.

  16. PREFACE: Nuclear Physics in Astrophysics III

    Science.gov (United States)

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

    2008-01-01

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

  17. Advances in astronomy and astrophysics 9

    CERN Document Server

    Kopal, Zdenek

    1972-01-01

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

  18. Magnetic processes in astrophysics theory, simulations, experiments

    CERN Document Server

    Rüdiger, Günther; Hollerbach, Rainer

    2013-01-01

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

  19. 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

  20. Advances in astronomy and astrophysics 7

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

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

  1. Spherical Panoramas for Astrophysical Data Visualization

    Science.gov (United States)

    Kent, Brian R.

    2017-05-01

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

  2. Theoretical nuclear structure and astrophysics at FAIR

    International Nuclear Information System (INIS)

    Rodríguez, Tomás R

    2014-01-01

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

  3. Byurakan Astrophysical Observatory as Cultural Centre

    Science.gov (United States)

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

    2017-07-01

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

  4. Kepler Planet Reliability Metrics: Astrophysical Positional Probabilities for Data Release 25

    Science.gov (United States)

    Bryson, Stephen T.; Morton, Timothy D.

    2017-01-01

    This document is very similar to KSCI-19092-003, Planet Reliability Metrics: Astrophysical Positional Probabilities, which describes the previous release of the astrophysical positional probabilities for Data Release 24. The important changes for Data Release 25 are:1. The computation of the astrophysical positional probabilities uses the Data Release 25 processed pixel data for all Kepler Objects of Interest.2. Computed probabilities now have associated uncertainties, whose computation is described in x4.1.3.3. The scene modeling described in x4.1.2 uses background stars detected via ground-based high-resolution imaging, described in x5.1, that are not in the Kepler Input Catalog or UKIRT catalog. These newly detected stars are presented in Appendix B. Otherwise the text describing the algorithms and examples is largely unchanged from KSCI-19092-003.

  5. A Companion to Astronomy and Astrophysics Chronology and Glossary with Data Tables

    CERN Document Server

    Lang, Kenneth R

    2006-01-01

    Astronomy and Astrophysics is a comprehensive, fundamental, up-to-date reference book. It is filled with vital information and basic facts for amateur astronomers and professional astrophysicists, and for anyone interested in the Universe, from the Earth and other planets to the stars, galaxies and beyond. Although serious and thorough, the language, and ideas will attract the general reader, as well as students and professionals. Astronomy and Astrophysics consists of two main parts, a Timeline and a Dictionary. The Timeline is a concise history, arranged chronologically, which provides the complete story of cosmic discovery from early Chinese and Greek astronomy to the latest findings of modern astrophysics and robotic spacecraft. It provides a sense of destination and flow in our growing awareness of the Universe. Each entry in the unfolding narrative is written in a concise, light and friendly style that will be appreciated by all, without being weighted down with incomprehensible specialized terms. The s...

  6. 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.

  7. The Astrophysics of Strongly Interacting Systems

    Science.gov (United States)

    Nerella, Tejaswi Venumadhav

    This thesis presents investigations in four areas of theoretical astrophysics: the production of sterile neutrino dark matter in the early Universe, the evolution of small-scale baryon perturbations during the epoch of cosmological recombination, the effect of primordial magnetic fields on the redshifted 21-cm emission from the pre-reionization era, and the nonlinear stability of tidally deformed neutron stars. In the first part of the thesis, we study the asymmetry-driven resonant production of 7 keV-scale sterile neutrino dark matter in the primordial Universe at temperatures T >~ 100 MeV. We report final DM phase space densities that are robust to uncertainties in the nature of the quark-hadron transition. We give transfer functions for cosmological density fluctuations that are useful for N-body simulations. We also provide a public code for the production calculation. In the second part of the thesis, we study the instability of small-scale baryon pressure sound waves during cosmological recombination. We show that for relevant wavenumbers, inhomogenous recombination is driven by the transport of ionizing continuum and Lyman-alpha photons. We find a maximum growth factor less than ≈ 1.2 in 107 random realizations of initial conditions. The low growth factors are due to the relatively short duration of the recombination epoch. In the third part of the thesis, we propose a method of measuring weak magnetic fields, of order 10--19 G (or 10--21 G if scaled to the present day), with large coherence lengths in the inter galactic medium prior to and during the epoch of cosmic reionization. The method utilizes the Larmor precession of spin-polarized neutral hydrogen in the triplet state of the hyperfine transition. We perform detailed calculations of the microphysics behind this effect, and take into account all the processes that affect the hyperfine transition, including radiative decays, collisions, and optical pumping by Lyman-alpha photons. In the final part of

  8. Charged-particle transfer reactions and nuclear astrophysics problems

    International Nuclear Information System (INIS)

    Artemov, S.V.; Yarmukhamedov, R.; Yuldashev, B.S.; Burtebaev, N.; Duysebaev, A.; Kadyrzhanov, K.K.

    2002-01-01

    In the report a review of the recent results of calculation of the astrophysical S-factors S(E) for the D(α, γ) 6 Li, 3 He(α, γ) 7 Be, 7 Be(p, γ) 8 Be, 12,13 C(p, γ) 13, 14 N and 12 C(p,γ) 16 O* reactions at extremely low energies E, including value E=0 , performed within the framework of a new method taking into account the additional information about the nuclear vertex constant (Nc) (or the respective asymptotic normalization coefficient) are presented. The required values of Nc can be obtained from an analysis of measured differential cross-sections of proton and α-particle transfer reactions (for example A( 3 He,d)B, 6 Li(d, 6 Li)d, 6 Li(α, 6 Li)α, 12 C( 6 Li, d) 16 O* etc.). A comparative analysis between the results obtained by different authors is also done. Taking into account an important role of the NVC's values for the nuclear astrophysical A(p, γ)B and A(α, γ)B reactions, a possibility of obtaining the reliable NVC values for the virtual decay B→A+p and B→A+α from the analysis of differential cross sections both sub- and above-barrier A( 3 He, d) and A( 6,7 Li, 2,3 H)B reactions is discussed in detail. In this line the use the isochronous cyclotron U-150 M, the 'DC-60' heavy ion machine and electrostatic charge-exchanging accelerator UKP-2-1 of Institute of Nuclear Physics of National Nuclear Center of the Republic of Kazakhstan for carrying out the needed experiments is considered and the possibility of the obtained data application for the astrophysical interest is also discussed

  9. Second advanced research workshop: Gravity, astrophysics and strings at the Black Sea. Proceedings

    International Nuclear Information System (INIS)

    Fiziev, P.; Todorov, M.

    2005-01-01

    The Second Advanced Workshop ‘Gravity, Astrophysics, and Strings’ held on 10-16 June 2004. It served four purposes: 1) Bringing together scientists from various branches of gravitational physics, astrophysics, and string theory gave an opportunity for interdisciplinary exchange of views and enhanced possible collaborations; 2) Provided a unique opportunity to scientists from various countries to communicate with colleagues on the hottest topics of gravitational physics, astrophysics, and string theory; 3) Opened new venue to young talented scientists to communicate and work with major research groups on the topics of the conference; 4) Stimulated creation of a new generation of young physicists for further development of the above basic topics in fundamental science. The workshop covered wide aspects of gravity, astrophysics, and string theory concerning the topics: Astrophysics; Mathematical Modeling and Numerical Simulations in Relativity; Relativistic Gravity; (Super)Strings. About 35 participants from Europe, America and Asia gave 28 invited talks and contributed presentations. They and guided general discussion as well, which took place confirmed the considerable interest to the themes of the workshop. The full text of 16 of the presented papers are included in this book

  10. Third advanced research workshop: Gravity, astrophysics and strings at the Black Sea. Proceedings

    International Nuclear Information System (INIS)

    Fiziev, P.; Todorov, M.

    2006-01-01

    The Third Advanced Workshop ‘Gravity, Astrophysics, and Strings’ held on 13-20 June 2005. The workshop: 1) Bringing together scientists from various branches of gravitational physics, astrophysics, particle physics, fundamental interactions and string theory gave an opportunity for interdisciplinary exchange of views and enhanced possible collaborations; 2) Provided a unique opportunity to scientists from various countries to communicate with colleagues on the hottest topics of gravitational physics, astrophysics, particle physics, fundamental interactions and string theory; 3) Opened new venue to young talented scientists to communicate and work with major research groups on the topics of the conference; 4) Stimulated creation of a new generation of young physicists for further development of the above basic topics in fundamental science. The workshop covered wide aspects of gravitational physics, astrophysics, particle physics, fundamental interactions and string theory concerning the topics: Astrophysics; Mathematical Modeling and Numerical Simulations in Relativity; Relativistic Gravity; Particle Physics and Fundamental Interactions; (Super)Strings. About 40 participants from Europe, America and Asia gave 32 invited talks and contributed presentations. They and guided general discussion as well, which took place confirmed the considerable interest to the themes of the workshop. The full text of 22 of the presented papers are included in this book

  11. Space astronomy and astrophysics program by CSA

    Science.gov (United States)

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

    2014-07-01

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

  12. Evolution and seismic tools for stellar astrophysics

    CERN Document Server

    Monteiro, Mario JPFG

    2008-01-01

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

  13. Astronomical optical interferometry, II: Astrophysical results

    Directory of Open Access Journals (Sweden)

    Jankov S.

    2011-01-01

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

  14. Nuclear astrophysics experiments with radioactive beams

    International Nuclear Information System (INIS)

    Leleux, P.

    2000-01-01

    In Nuclear Astrophysics, experiments with radioactive beams present particular problems (e.g. low beam intensity, large background) to which specific solutions (i.e. non-standard detection setup) can be brought. Selected reactions measured in Louvain-la-Neuve are treated as practical examples. (author)

  15. Virtually Lossless Compression of Astrophysical Images

    Directory of Open Access Journals (Sweden)

    Stefano Baronti

    2005-09-01

    Full Text Available We describe an image compression strategy potentially capable of preserving the scientific quality of astrophysical data, simultaneously allowing a consistent bandwidth reduction to be achieved. Unlike strictly lossless techniques, by which moderate compression ratios are attainable, and conventional lossy techniques, in which the mean square error of the decoded data is globally controlled by users, near-lossless methods are capable of locally constraining the maximum absolute error, based on user's requirements. An advanced lossless/near-lossless differential pulse code modulation (DPCM scheme, recently introduced by the authors and relying on a causal spatial prediction, is adjusted to the specific characteristics of astrophysical image data (high radiometric resolution, generally low noise, etc.. The background noise is preliminarily estimated to drive the quantization stage for high quality, which is the primary concern in most of astrophysical applications. Extensive experimental results of lossless, near-lossless, and lossy compression of astrophysical images acquired by the Hubble space telescope show the advantages of the proposed method compared to standard techniques like JPEG-LS and JPEG2000. Eventually, the rationale of virtually lossless compression, that is, a noise-adjusted lossles/near-lossless compression, is highlighted and found to be in accordance with concepts well established for the astronomers' community.

  16. Astrophysics, cosmology and high energy physics

    International Nuclear Information System (INIS)

    Rees, M.J.

    1983-01-01

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

  17. Pulsars as tools for fundamental physics & astrophysics

    NARCIS (Netherlands)

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

    2004-01-01

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

  18. Particle physics-astrophysics working group

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  19. Nuclear astrophysics experiments with Pohang neutron facility

    International Nuclear Information System (INIS)

    Kim, Yeong Duk; Yoo, Gwang Ho

    1998-01-01

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

  20. 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…

  1. 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 f...

  2. Balance in the NASA Astrophysics Program

    Science.gov (United States)

    Elvis, Martin

    2017-08-01

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

  3. General relativity and relativistic astrophysics. Second edition

    International Nuclear Information System (INIS)

    Straumann, N.

    1984-01-01

    This book discusses general relativity and relativistic astrophysics. It is written in three parts. Part I develops the mathematical tools used in the general theory of relativity, Part II develops the general theory of relativity along traditional lines, and Part III treats aspects of the physics of compact objects

  4. The Astrophysics Simulation Collaboratory portal: A framework foreffective distributed research

    Energy Technology Data Exchange (ETDEWEB)

    Bondarescu, Ruxandra; Allen, Gabrielle; Daues, Gregory; Kelly,Ian; Russell, Michael; Seidel, Edward; Shalf, John; Tobias, Malcolm

    2003-03-03

    We describe the motivation, architecture, and implementation of the Astrophysics Simulation Collaboratory (ASC) portal. The ASC project provides a web-based problem solving framework for the astrophysics community that harnesses the capabilities of emerging computational grids.

  5. Preface: Eighth European Summer School on Experimental Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Claudio, Spitaleri; Livio, Lamia; Gianluca, Pizzone Rosario

    2016-01-01

    often quoted statement of Carl Sagan, “We are all star stuff,” is exhaustively describing one of the great discoveries of the 20th century as well as the main aim of nuclear astrophysics. The present theory of stellar nucleosynthesis (based on the famous paper B 2 FH) predicts chemical evolution of the Universe, which is testable by looking at stellar spectral lines, meteorites, pre-solar grains or other means of investigation. Quantum mechanics explains why different atoms emit light at characteristic wavelengths, and so by studying the light emitted from different stars, one may infer the atmospheric composition of individual stars. However, upon undertaking such a task, observations indicate a strong correlation between a star’s heavy element content (metallicity) and its age (red shift). Big bang nucleosynthesis tells us that the early universe consisted of only the light elements, and so one expects the first stars to be composed of hydrogen, helium, and lithium, the three lightest elements. The recent achievements of WMAP and Planck missions, with the precise measurement of many cosmological parameters, have re-ignited the interest on the primordial nucleosynthesis, especially for the still unclear Lithium primordial abundance. Stellar structure and the H-R diagram indicate that the lifetime of a star depends greatly on its initial mass and chemical composition, so that massive stars are very short-lived, and less massive stars are longer-lived. As a star dies, nuclear astrophysics argues that it will enrich the interstellar medium with “heavy elements” (in this case all elements heavier than lithium, the third element), from which new stars are formed. This account is consistent with the observed correlation between stellar metallicity and red shift. The theory of stellar nucleosynthesis would not be very convincing if reliable nuclear physics inputs are adopted. By carefully scrutinizing the table of nuclides, nuclear astrophysicists were able to

  6. NASA Astrophysics EPO Resources For Engaging Girls in Science

    Science.gov (United States)

    Sharma, M.; Mendoza, D.; Smith, D.; Hasan, H.

    2011-09-01

    A new collaboration among the NASA Science Mission Directorate (SMD) Astrophysics EPO community is to engage girls in science who do not self-select as being interested in science, through the library setting. The collaboration seeks to (i) improve how girls view themselves as someone who knows about, uses, and sometimes contributes to science, and (ii) increase the capacity of EPO practitioners and librarians (both school and public) to engage girls in science. As part of this collaboration, we are collating the research on audience needs and best practices, and SMD EPO resources, activities and projects that focus on or can be recast toward engaging girls in science. This ASP article highlights several available resources and individual projects, such as: (i) Afterschool Universe, an out-of-school hands-on astronomy curriculum targeted at middle school students and an approved Great Science for Girls curriculum; (ii) Big Explosions and Strong Gravity, a Girl Scout patch-earning event for middle school aged girls to learn astronomy through hands-on activities and interaction with actual astronomers; and (iii) the JWST-NIRCAM Train the Trainer workshops and activities for Girl Scouts of USA leaders; etc. The NASA Astrophysics EPO community welcomes the broader EPO community to discuss with us how best to engage non-science-attentive girls in science, technology, engineering, and mathematics (STEM), and to explore further collaborations on this theme.

  7. CHOLLA: A NEW MASSIVELY PARALLEL HYDRODYNAMICS CODE FOR ASTROPHYSICAL SIMULATION

    International Nuclear Information System (INIS)

    Schneider, Evan E.; Robertson, Brant E.

    2015-01-01

    We present Computational Hydrodynamics On ParaLLel Architectures (Cholla ), a new three-dimensional hydrodynamics code that harnesses the power of graphics processing units (GPUs) to accelerate astrophysical simulations. Cholla models the Euler equations on a static mesh using state-of-the-art techniques, including the unsplit Corner Transport Upwind algorithm, a variety of exact and approximate Riemann solvers, and multiple spatial reconstruction techniques including the piecewise parabolic method (PPM). Using GPUs, Cholla evolves the fluid properties of thousands of cells simultaneously and can update over 10 million cells per GPU-second while using an exact Riemann solver and PPM reconstruction. Owing to the massively parallel architecture of GPUs and the design of the Cholla code, astrophysical simulations with physically interesting grid resolutions (≳256 3 ) can easily be computed on a single device. We use the Message Passing Interface library to extend calculations onto multiple devices and demonstrate nearly ideal scaling beyond 64 GPUs. A suite of test problems highlights the physical accuracy of our modeling and provides a useful comparison to other codes. We then use Cholla to simulate the interaction of a shock wave with a gas cloud in the interstellar medium, showing that the evolution of the cloud is highly dependent on its density structure. We reconcile the computed mixing time of a turbulent cloud with a realistic density distribution destroyed by a strong shock with the existing analytic theory for spherical cloud destruction by describing the system in terms of its median gas density

  8. 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.

  9. The Neutrino: A Better Understanding Through Astrophysics: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kneller, James P. [North Carolina State Univ., Raleigh, NC (United States)

    2016-10-12

    The final report for the award "The Neutrino: A Better Understanding Through Astrophysics" is given. The goals of the work were the following: to construct new theoretical approaches to the problem of neutrino propagation in media including where neutrino-neutrino interactions are important; to pioneer the use of new approaches, including super-scattering operators, for the evolution of neutrino thermal and statistical ensembles; to implement these new approaches in computer codes to study neutrino evolution in supernovae and other hot, dense environments; to increase the realism of simulated signals of a Galactic supernovae neutrino burst in current and future neutrino detectors; to study the simulated signals to determine the ability to extract information on the missing neutrino mixing parameters and the dynamics of the supernova explosion; and to study sterile neutrinos and non-standard interactions of neutrinos in supernovae and their effect upon the signal. Accomplishments made in these areas are described.

  10. The Neutrino: A Better Understanding Through Astrophysics: Final Report

    International Nuclear Information System (INIS)

    Kneller, James P.

    2016-01-01

    The final report for the award 'The Neutrino: A Better Understanding Through Astrophysics' is given. The goals of the work were the following: to construct new theoretical approaches to the problem of neutrino propagation in media including where neutrino-neutrino interactions are important; to pioneer the use of new approaches, including super-scattering operators, for the evolution of neutrino thermal and statistical ensembles; to implement these new approaches in computer codes to study neutrino evolution in supernovae and other hot, dense environments; to increase the realism of simulated signals of a Galactic supernovae neutrino burst in current and future neutrino detectors; to study the simulated signals to determine the ability to extract information on the missing neutrino mixing parameters and the dynamics of the supernova explosion; and to study sterile neutrinos and non-standard interactions of neutrinos in supernovae and their effect upon the signal. Accomplishments made in these areas are described.

  11. 3rd Session of the Sant Cugat Forum on Astrophysics

    CERN Document Server

    Gravitational wave astrophysics

    2015-01-01

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

    Information for Authors. Journal of Astrophysics and Astronomy. The Journal of Astrophysics and Astronomy publishes papers on all aspects of Astrophysics and Astronomy, including instrumentation. The submission of a paper will be held to imply that it represents the results of original research not previously published; ...

  14. FOREWORD: Workshop on "Very Hot Astrophysical Plasmas"

    Science.gov (United States)

    Koch-Miramond, Lydie; Montemerie, Thierry

    1984-01-01

    A Workshop on "Very Hot Astrophysical Plasmas" was held in Nice, France, on 8-10 November 1982. Dedicated mostly to theoretical, observational, and experimental aspects of X-ray astronomy and related atomic physics, it was the first of its kind to be held in France. The Workshop was "European" in the sense that one of its goals (apart from pure science) was to gather the European astronomical community in view of the forthcoming presentation of the "X-80" project for final selection to be the next scientific satellite of the European Space Agency. We now know that the Infrared Space Observatory has been chosen instead, but the recent successful launch of EXOSAT still keeps X-ray astronomy alive, and should be able to transfer, at least for a time, the leadership in this field from the U.S. to Europe, keeping in mind the competitive level of our Japanese colleagues. (With respect to the selection of ISO, one should also keep in mind that observations in the infrared often bring material relevant to the study of X-ray sources!) On a longer time scale, the Workshop also put emphasis on several interesting projects for the late eighties-early nineties, showing the vitality of the field in Europe. Some proposals have already taken a good start, like XMM, the X-ray Multi-Mirror project, selected by ESA last December for an assessment study in 1983. The present proceedings contain most of the papers that were presented at the Workshop. Only the invited papers were presented orally, contributed papers being presented in the form of posters but summarized orally by rapporteurs. To make up this volume, the written versions of these papers were either cross-reviewed by the Invited Speakers, or refereed by the Rapporteurs (for contributed papers) and edited by us, when necessary. Note, however, that the conclusions of the Workshop, which were kindly presented by Richard McCray, have already appeared in the "News and Views" section of Nature (301, 372, 1983). Altogether, the

  15. 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

  16. Astrophysics of Super-Massive Black Hole Mergers

    Science.gov (United States)

    Schnittman, Jeremy D.

    2013-01-01

    We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances, even in the absence of a space-based gravitational-wave observatory. In addition to providing a mechanism for observing SMBH mergers, EM counterparts also give important information about the environments in which these remarkable events take place, thus teaching us about the mechanisms through which galaxies form and evolve symbiotically with their central black holes.

  17. Worrying about the LHC, a lesson from astrophysics?

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    To worry about the LHC is a popular sport. I shall share my own worries, hopefully original, and do it via a parable (for this method, I can quote earlier authors). The parable concerns a topic in astrophysics (gamma-ray bursts) which happens to be a simple exercise --but quite an interesting one-- on elementary particle-physics and beam dynamics, topics not unrelated to the LHC. Though most of the talk will be dedicated to the physics and, in particular, to its recent developments, the allegory will allow me to detect what, I shall argue, may be dangerous 'viruses' invading science. I do not have the decisive antidotes, but I shall discuss some possible ones.

  18. Extrasolar Planets Swiss Society for Astrophysics and Astronomy

    CERN Document Server

    Cassen, Patrick; Quirrenbach, Andreas

    2006-01-01

    Research on extrasolar planets is one of the most exciting fields of activity in astrophysics. In a decade only, a huge step forward has been made from the early speculations on the existence of planets orbiting "other stars" to the first discoveries and to the characterization of extrasolar planets. This breakthrough is the result of a growing interest of a large community of researchers as well as the development of a wide range of new observational techniques and facilities. Based on their lectures given at the 31st Saas-Fee Advanced Course, Andreas Quirrenbach, Tristan Guillot and Pat Cassen have written up up-to-date comprehensive lecture notes on the "Detection and Characterization of Extrasolar Planets", "Physics of Substellar Objects Interiors, Atmospheres, Evolution" and "Protostellar Disks and Planet Formation". This book will serve graduate students, lecturers and scientists entering the field of extrasolar planets as detailed and comprehensive introduction.

  19. Relativistic kinetic theory with applications in astrophysics and cosmology

    CERN Document Server

    Vereshchagin, Gregory V

    2017-01-01

    Relativistic kinetic theory has widespread application in astrophysics and cosmology. The interest has grown in recent years as experimentalists are now able to make reliable measurements on physical systems where relativistic effects are no longer negligible. This ambitious monograph is divided into three parts. It presents the basic ideas and concepts of this theory, equations and methods, including derivation of kinetic equations from the relativistic BBGKY hierarchy and discussion of the relation between kinetic and hydrodynamic levels of description. The second part introduces elements of computational physics with special emphasis on numerical integration of Boltzmann equations and related approaches, as well as multi-component hydrodynamics. The third part presents an overview of applications ranging from covariant theory of plasma response, thermalization of relativistic plasma, comptonization in static and moving media to kinetics of self-gravitating systems, cosmological structure formation and neut...

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

    Science.gov (United States)

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; Bernstein, Lee A.; Blackmon, Jeffrey C.; Messer, Bronson; Brown, B. Alex; Brown, Edward F.; Brune, Carl R.; Champagne, Art E.; Chieffi, Alessandro; Couture, Aaron J.; Danielewicz, Pawel; Diehl, Roland; El-Eid, Mounib; Escher, Jutta E.; Fields, Brian D.; Fröhlich, Carla; Herwig, Falk; Hix, William Raphael; Iliadis, Christian; Lynch, William G.; McLaughlin, Gail C.; Meyer, Bradley S.; Mezzacappa, Anthony; Nunes, Filomena; O'Shea, Brian W.; Prakash, Madappa; Pritychenko, Boris; Reddy, Sanjay; Rehm, Ernst; Rogachev, Grigory; Rutledge, Robert E.; Schatz, Hendrik; Smith, Michael S.; Stairs, Ingrid H.; Steiner, Andrew W.; Strohmayer, Tod E.; Timmes, F. X.; Townsley, Dean M.; Wiescher, Michael; Zegers, Remco G. T.; Zingale, Michael

    2017-05-01

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

  1. Nuclear Astrophysics with the Trojan Horse Method

    Science.gov (United States)

    Spitaleri, Claudio

    2015-04-01

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

  2. Modern fluid dynamics for physics and astrophysics

    CERN Document Server

    Regev, Oded; Yecko, Philip A

    2016-01-01

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

  3. International Conference on Particle Physics and Astrophysics

    CERN Document Server

    2015-01-01

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

  4. Plasma Astrophysics, Part II Reconnection and Flares

    CERN Document Server

    Somov, Boris V

    2013-01-01

    This two-part book is devoted to classic fundamentals and current practices and perspectives of modern plasma astrophysics. This second part discusses the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas in the solar system, single and double stars, relativistic objects, accretion disks and their coronae. More than 25% of the text is updated from the first edition, including the additions of new figures, equations and entire sections on topics such as topological triggers for solar flares and the magnetospheric physics problem. This book is aimed at professional researchers in astrophysics, but it will also be useful to graduate students in space sciences, geophysics, applied physics and mathematics, especially those seeking a unified view of plasma physics and fluid mechanics.

  5. New developments for high-energy astrophysics

    CERN Document Server

    Paul, J

    2000-01-01

    Unlike nearly all branches of physics, founded on the elaboration and analysis of experiments, astronomy is, above all, a science of observation, based mainly on the detection and study of the electromagnetic radiation emitted by celestial bodies. If one excepts devices operating in the radio bands, nearly all instruments used in astrophysics are based on the detection of photons. This review intends to highlight recent developments in high-energy astronomy and astrophysics studies from ground and space observations (from the X-ray band up to high-energy gamma-rays and neutrinos). Particular attention will be given not only to recent technologies of photodetection now at work in the field of high-energy astronomy and to emerging photodetection studies in progress for future missions, but also to advanced imaging techniques used in the high-energy domain, which beyond any doubt, constitutes the most arduous of new astronomical disciplines.

  6. 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.)

  7. Visualization needs and techniques for astrophysical simulations

    International Nuclear Information System (INIS)

    Kapferer, W; Riser, T

    2008-01-01

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

  8. 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.

  9. Planetary magnetospheres: the in situ astrophysical laboratories

    International Nuclear Information System (INIS)

    Krimigis, S.M.

    1982-01-01

    The magnetosphere of Earth is described first because it represents the one most extensively studied to date, and serve as the baseline for characterizing the phenomena to be observed in other planetary magnetospheres. The magnetospheres of the inner planets (Mercury, Venus and Mars) are examined next and then a description of the magnetospheres of the outer planets are presented. The description of the magnetosphere of Jupiter form the bulk of the paper, not only because of its enormous size and rich variety of physical phenomena within, but because it may represent the closest analog to the many astrophysical objects thought to possess magnetospheres. Several properties characteristic of magnetospheres in general will then be pointed out, and the significance of the findings is discussed in the context of solar system and astrophysical plasmas

  10. Weeding the Astrophysical Garden: Ethyl Cyanide

    Science.gov (United States)

    De Lucia, F. C.; Fortman, S. M.; Medvedev, I. R.; Neese, C. F.

    2009-12-01

    It is well known that many, if not most, of the unidentified features in astrophysical spectra arise from relatively low lying excited vibrational and torsional states of a relatively small number of molecular species— the astrophysical weeds. It is also well known that the traditional quantum mechanical assignment and fitting of these excited state spectra is a formidable task, one that is made harder by the expected perturbations and interactions among these states. We have previously proposed an alternative fitting and analysis approach based on experimental, intensity calibrated spectra taken at many temperatures. In this paper we discuss the implementation of this approach and provide details in the context of one of these weeds, ethyl cyanide.

  11. 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.

  12. 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.

  13. Visualization needs and techniques for astrophysical simulations

    Science.gov (United States)

    Kapferer, W.; Riser, T.

    2008-12-01

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

  14. Astrophysical and terrestrial neutrinos in Supernova detectors

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1985-09-01

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

  15. Neutrino masses in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Raffelt, G.G.

    1996-01-01

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

  16. An anelastic approximation arising in astrophysics

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Feireisl, Eduard

    2017-01-01

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

  17. Neutrino masses in astrophysics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-11-01

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

  18. An anelastic approximation arising in astrophysics

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Feireisl, Eduard

    2017-01-01

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

  19. "Other" indirect methods for nuclear astrophysics

    Science.gov (United States)

    Trache, Livius

    2018-01-01

    In the house of Trojan Horse Method (THM), I will say a few words about "other" indirect methods we use in Nuclear Physics for Astrophysics. In particular those using Rare Ion Beams that can be used to evaluate radiative proton capture reactions. I add words about work done with the Professore we celebrate today. With a proposal, and some results with TECSA, for a simple method to produce and use isomeric beam of 26mAl.

  20. MESA: Modules for Experiments in Stellar Astrophysics

    Science.gov (United States)

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

    2010-10-01

    Stellar physics and evolution calculations enable a broad range of research in astrophysics. Modules for Experiments in Stellar Astrophysics (MESA) is a suite of open source libraries for a wide range of applications in computational stellar astrophysics. A newly designed 1-D stellar evolution module, MESA star, combines many of the numerical and physics modules for simulations of a wide range of stellar evolution scenarios ranging from very-low mass to massive stars, including advanced evolutionary phases. MESA star solves the fully coupled structure and composition equations simultaneously. It uses adaptive mesh refinement and sophisticated timestep controls, and supports shared memory parallelism based on OpenMP. Independently usable modules provide equation of state, opacity, nuclear reaction rates, and atmosphere boundary conditions. Each module is constructed as a separate Fortran 95 library with its own public interface. Examples include comparisons to other codes and show evolutionary tracks of very low mass stars, brown dwarfs, and gas giant planets; the complete evolution of a 1 Msun star from the pre-main sequence to a cooling white dwarf; the Solar sound speed profile; the evolution of intermediate mass stars through the thermal pulses on the He-shell burning AGB phase; the interior structure of slowly pulsating B Stars and Beta Cepheids; evolutionary tracks of massive stars from the pre-main sequence to the onset of core collapse; stars undergoing Roche lobe overflow; and accretion onto a neutron star.

  1. 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.)

  2. 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 wormholes can be divided into four classes during the evolutionary processes of the universe 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.

  3. [Petrological Analysis of Astrophysical Dust Analog Evolution

    Science.gov (United States)

    Rietmeijer, Frans J. M.

    1997-01-01

    This project "Petrological analysis of astrophysical dust analog evolution" was initiated to try to understand the vapor phase condensation, and the nature of the reaction products, in circumstellar environments, such as the solar nebula 4,500 Myrs ago, and in the interstellar medium. Telescope-based infrared [IR] spectroscopy offers a broad-scale inventory of the various types of dust in these environments but no details on small-scale variations in terms of chemistry and morphology and petrological phase relationships. Vapor phase condensation in these environments is almost certainly a non-equilibrium process. The main challenge to this research was to document the nature of this process that, based on astrophysical observations, seems to yield compositionally consistent materials. This observation may suggest a predictable character during non-equilibrium condensation. These astrophysical environments include two chemically distinct, that is, oxygen-rich and carbon-rich environments. The former is characterized by silicates the latter by carbon-bearing solids. According to cosmological models of stellar evolution circumstellar dust accreted into protoplanets wherein thermal and/or aqueous processes will alter the dust under initially, non-equilibrium conditions.

  4. 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.

  5. 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.

  6. Proceedings of the 2nd Iberian Nuclear Astrophysics Meeting on Compact Stars

    CERN Document Server

    Pons, J; Albertus, C; 10.1088/1742-6596/342/1/011001

    2012-01-01

    This volume contains most of the links to the presentations delivered at this international workshop. This meeting was the second in the series following the previous I Encuentro Ib\\'erico de Compstar, held at the University of Coimbra, Portugal in 2010. The main purpose of this meeting was to strengthen the scientific collaboration between the participants of the Iberian and the rest of the southern European branches of the European Nuclear Astrophysics network, formerly, COMPSTAR. This ESF (European Science Foundation) supported network has been crucial in helping to make a broader audience for the the most interesting and relevant research lines being developed currently in Nuclear Astrophysics, especially related to the physics of neutron stars. The program of the meeting was tailored to theoretical descriptions of the physics of neutron stars although some input from experimental observers and other condensed matter and optics areas of interest was also included.

  7. 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

  8. Karl Schwarzschild and the professionalization of astrophysics. (German Title: Karl Schwarzschild und die Professionalisierung der Astrophysik)

    Science.gov (United States)

    Schmidt-Kaler, Theodor

    Professionalization is characteristic for physics and astronomy since 1830, and forms the basis for their rapid evolution in the 20th century. Karl Schwarzschild's contributions to professionalization of astronomy are presented: the introduction of course lectures in a repeating cycle, a permanent astrophysical laboratory, a tight connection between teaching and research, simulations and suggestions for astronomy at high schools and for the training of high school teachers, an interest in international organisation, and the initiative and planning of a southern observatory.

  9. Recent Results In Nuclear Astrophysics At The n_TOF Facility At CERN

    CERN Document Server

    Tagliente, Giuseppe; Andrzejewski, J; Audouin, L; Bacak, M; Balibrea, J; Barbagallo, M; Bečvář, F; Berthoumieux, E; Billowes, J; Bosnar, D; Brown, A; Caamaño, M; Calviño, F; Calviani, M; Cano-Ott, D; Cardella, R; Casanovas, A; Cerutti, F; Chen, Y H; Chiaveri, E; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Cosentino; Damone, L A; Diakaki, M; Domingo-Pardo, C; Dressler, L R; Dupont, E; Durán, I; Fernández-Domínguez, B; Ferrari, A; Ferreira, P; Finocchiaro, P; Furman, V; Göbel, K; García, A R; Gawlik, A; Gilardoni, S; Glodariu, T; Gonçalves, I F; González, E; Griesmayer, E; Guerrero, C; Gunsing, F; Harada, H; Heinitz, S; Heyse, J; Jenkins, D G; Jericha, E; Käppeler, F; Kadi, Y; Kalamara, A; Kavrigin, P; Kimura, A; Kivel, N; Kokkoris, M; Krtička, M; Kurtulgil, D; Leal-Cidoncha, E; Lederer, C; Lerendegui-Marco, J; Leeb, H; Lo Meo, S; Lonsdale, S J; Macina, D; Marganiec, J; Martínez, T; Masi, A; Massimi, C; Mastinu, P; Mastromarco, M; Maugeri, E A; Mazzone, A; Mendoza, E; Mengoni, A; Mingrone, F; Milazzo, P M; Musumarra, A; Negret, A; Nolte, R; Oprea, A; Patronis, N; Pavlik, A; Perkowski, J; Porras, I; Praena, J; Quesada, J M; Radeck, D; Rauscher, T; Reifarth, R; Rubbia, C; Ryan, J A; Sabaté-Gilarte, M; Saxena, A; Schillebeeckx, P; Schumann, D; Sedyshev, P; Smith, A G; Sosnin, N V; Stamatopoulos, A; Tain, J L; Tarifeño-Saldivia, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Vlachoudis, V; Vlastou, R; Wallner, A; Warren, S; Woods, P J; Żugec, P Č

    2017-01-01

    The neutron time of flight (n_TOF) facility at CERN is a spallation source characterized by a white neutron spectrum. The innovative features of the facility, in the two experimental areas, (20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. The recent results obtained at n_TOF facility are presented.

  10. Study of the fragmentation of astrophysical interest molecules (CnHm) induced by high velocity collision

    International Nuclear Information System (INIS)

    Tuna, Th.

    2008-07-01

    This work shows the study of atom-molecule collision processes in the high velocity domain (v=4,5 a.u). The molecules concerned by this work are small unsaturated hydrocarbons C 1-4 H and C 3 H 2 . Molecules are accelerated with the Tandem accelerator in Orsay and their fragmentation is analyzed by the 4π, 100% efficient detector, AGAT. Thanks to a shape analysis of the current signal from the silicon detectors in association with the well known grid method, we are able to measure all the fragmentation channels of the incident molecule. These dissociation measurements have been introduced in the modelization of two objects of the interstellar medium in which a lot of hydrocarbon molecules have been observed (TMC1, horse-head nebula). We have extended our branching ratios obtained by high velocity collision to other electronic processes included in the chemical database like photodissociation and dissociative recombination. This procedure is feasible under an assumption of the statistical point of view of the molecular fragmentation. The deviations following our modification are very small in the modelization of TMC1 but significant in the photodissociation region. The first part is dedicated to the description of the experimental setting that has enabled us to study the fragmentation of C n H m molecules: the Orsay's Tandem accelerator and the Agat detector. The second part deals with negative ion sources and particularly with the Sahat source that is based on electronic impact and has shown good features for the production of anions and correct stability for its use with accelerators. The third part is dedicated to the experimental results in terms of cross-sections, number of fragments and branching ratios, associated to the various collisional processes. The last part presents an application of our measurement of fragmentation data to astro-chemistry. In this field, the simulation codes of the inter-stellar medium require databases of chemical reactions that depend on the issues of the fragmentation processes

  11. Fusion cross section measurements of astrophysical interest for light heavy ions systems within the STELLA project

    Directory of Open Access Journals (Sweden)

    Fruet Guillaume

    2017-01-01

    The experimental setup composed of an ultra high vacuum reaction chamber, a set of 3 silicon strip detectors, up to 36 LaBr3(Ce scintillators from the UK FATIMA collaboration, and a fast rotating target system will be described. The 12C+12C fusion reaction has been studied from Elab = 11 to 5.6 MeV using STELLA at the Andromède facility in Orsay, France. Preliminary commissioning results are presented in this article.

  12. PREFACE: Second School on Cosmic Rays and Astrophysics

    Science.gov (United States)

    Zepeda, Arnulfo

    2008-02-01

    The physics of cosmic rays, gamma rays and neutrinos has become nowadays a subject of fast development. On the other hand present and planed experimental facilities installed in the American continent, attract and facilitate the involvement of local young researchers. For these reasons Professor Oscar Saavedra and his team of the high altitude cosmic ray Chacaltaya laboratory and the Universidad Mayor de San Andres in La Paz Bolivia, conceived the idea of organizing the First School on Cosmic Rays and Astrophysics in La Paz 9-20 August 2004. That school was possible, in spite of the scarcity of funds, thanks to the solidary participation of several distinguish lecturers who paid their travel and local expenses. Their lectures were made available on a CD by the local students. It was then decided that a second school be organized for 2006 in Mexico. It was held from 28 August to 15 September 15. Some of the lecturers in this Second School on Cosmic Rays and Astrophysics were too busy to write their lectures, but here we put at the disposal of the interested community the contributions of Roberto Battiston, Karen S Caballero, Edgar Casimiro, David Delepine, Giorgio Giacomelli, Gonzalo Rodríguez and Luis Villaseñor. This School was possible thanks to the financial assistance of CONACyT (Mexico), the Benemerita Universidad Autonoma de Puebla, Centro de Investigacion y de Estudios Avanzados (Cinvestav), the University of Torino and the Centro Latino Americano de Fisica. Arnulfo Zepeda The editors of these proceedings are: Rebeca López Rodrigo Pelayo Oscar Saavedra Arnulfo Zepeda

  13. Measurement of reaction rates of interest in stellar structure and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Terrasi, F.; D`Onofrio, A. [Dipt. di Scienze Ambientali, Seconda Univ. di Napoli, Caserta (Italy)]|[INFN, Napoli (Italy); Campajola, L.; Imbriani, G. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy); Gialanella, L. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy)]|[Inst. fuer Experimentalphysik III, Ruhr-Univ. Bochum, Bochum (Germany); Greife, U.; Rolfs, C.; Strieder, F.; Trautvetter, H.P. [Inst. fuer Experimentalphysik III, Ruhr-Univ. Bochum, Bochum (Germany); Roca, V.; Romano, M. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy); Straniero, O. [Osservatorio Astronomico di Collurania, Teramo (Italy)

    1998-06-01

    Accurate determinations of reaction rates at astrophysical energies are very important in stellar structure and evolution studies. The cases of two key reactions, namely {sup 7}Be(p,{gamma}){sup 8}B and {sup 12}C({alpha},{gamma}){sup 16}O are discussed, both from the point of view of their astrophysical interest and of the experimental difficulties in the measurement of their cross section. (orig.)

  14. Modules for Experiments in Stellar Astrophysics (MESA)

    Science.gov (United States)

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

    2011-01-01

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

  15. BOOK REVIEW: Particle Astrophysics (Second Edition)

    Science.gov (United States)

    Bell, Nicole

    2009-07-01

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

  16. 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

  17. Underground Nuclear Astrophysics Experiment JUNA in China

    Science.gov (United States)

    Liu, W. P.

    Underground Nuclear Astrophysics Experiment in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. A 400 kV high current accelerator with an ECR source and γ , neutron and charged particle detectors will be set up. We plan to study directly a number of nuclear reactions important to hydrostatic stellar evolution near their Gamow window energies such as 25Mg(p, γ )26Al, 19F(p, α )16O, 13C(α , n)16O, and 12C(α , γ )16O, by the end of 2019.

  18. 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.

  19. Showing Complex Astrophysical Settings Through Virtual Reality

    Science.gov (United States)

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

    2018-01-01

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

  20. Nuclear Data on Unstable Nuclei for Astrophysics

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  1. Nonlinear evolution of astrophysical Alfven waves

    Science.gov (United States)

    Spangler, S. R.

    1984-01-01

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

  2. Dimensional analysis and group theory in astrophysics

    CERN Document Server

    Kurth, Rudolf

    2013-01-01

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

  3. 3D Immersive Visualization with Astrophysical Data

    Science.gov (United States)

    Kent, Brian R.

    2017-01-01

    We present the refinement of a new 3D immersion technique for astrophysical data visualization.Methodology to create 360 degree spherical panoramas is reviewed. The 3D software package Blender coupled with Python and the Google Spatial Media module are used together to create the final data products. Data can be viewed interactively with a mobile phone or tablet or in a web browser. The technique can apply to different kinds of astronomical data including 3D stellar and galaxy catalogs, images, and planetary maps.

  4. 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 linear regime, the dynamo saturates at a level significantly higher than normal turbulent dynamos, namely at exact equipartition when the magnetic Prandtl number Prm~ 1. Visualization of the magnetic and velocity fields at saturation will help us to understand some of the aspects of the non-linear dynamo...

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

    Science.gov (United States)

    Swinbank, Elizabeth

    1997-01-01

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

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

    International Nuclear Information System (INIS)

    Smith, Michael Scott

    2011-01-01

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

  7. Demonstration of Submillimeter Astrophysics Technology at Caltech Submillimeter Observatory

    Data.gov (United States)

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

  8. New Worlds, New Horizons in Astronomy and Astrophysics

    National Research Council Canada - National Science Library

    2010-01-01

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

  9. 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.

  10. Astrophysical dark matter: candidates from particle physics and detection possibilities

    International Nuclear Information System (INIS)

    Freese, K.

    1989-01-01

    In this talk, I will discuss the arguments that 50% to 90% of the matter in galaxies, including our own, is made of an unknown type of dark matter. I will review the reason why cosmologists believe Ω = 1 and illustrate the contrast with the limits on the amount of baryonic matter from element abundances in Big Bang Nucleosynthesis. Other arguments for nonbaryonic dark matter will also be discussed. Candidates for the dark matter from particle physics will be presented. I will focus on cold dark matter candidates known as WIMPs, weakly interacting massive (O(GeV)) particles. I will try to illustrate why these particles are interesting for astrophysics and outline ideas for cornering them. Detection possibilities for these particles include indirect detection, which takes advantage of the annihilation products of these particles in the galactic halo, the sun, or the earth. Direct detection via newly proposed cryogenic detectors must be sensitive to <∼ keV energy deposits. Annual modulation of the dark matter signal can be used as a signature for these halo particles. I hope to motivate the interest in these particles and discuss ideas for finding them

  11. 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...

  12. 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)

  13. The CATS Service: An Astrophysical Research Tool

    Directory of Open Access Journals (Sweden)

    O V Verkhodanov

    2009-03-01

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

  14. 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.

  15. Art as a Vehicle for Nuclear Astrophysics

    Science.gov (United States)

    Kilburn, Micha

    2013-04-01

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

  16. Communicating the Science from NASA's Astrophysics Missions

    Science.gov (United States)

    Hasan, Hashima; Smith, Denise A.

    2015-01-01

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

  17. Time-symmetric integration in astrophysics

    Science.gov (United States)

    Hernandez, David M.; Bertschinger, Edmund

    2018-01-01

    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 which 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 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 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 favored. We also show that time-symmetry and time-reversibility are properties that are distinct for an integrator.

  18. Advancing Astrophysics with the Square Kilometre Array

    CERN Document Server

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

    2015-01-01

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

  19. Black Hole Astrophysics The Engine Paradigm

    CERN Document Server

    Meier, David L

    2012-01-01

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

  20. Interest rate derivatives

    DEFF Research Database (Denmark)

    Svenstrup, Mikkel

    This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered.......This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered....

  1. AtomPy: A Cloud Atomic-data Service for Astrophysical Applications

    Science.gov (United States)

    Mendoza, Claudio; Boswell, J. S.; Bautista, M.

    2013-06-01

    Apart from our long-term commitment to the computing of accurate atomic data for astrophysical applications, we have also been interested in the problems of data access and dissemination. In this respect, one of us took part in the developments of TIPTOPbase [1, 2, 3], the astrophysical opacity server referred to as OPserver [4, 5], and, more recently, of the Virtual Atomic and Molecular Data Center [6, 7]. Our present effort is now with the establishment of a cloud atomic data web service, AtomPy, implemented by means of SOAP web services, Google Drive spreadsheets and Python modules. In the present poster we will describe the outline of this ambitious project, illustrated with some prototypes that are already operational.

  2. The 8Li(α, n)11B Reaction Rate at Astrophysical Temperatures

    Science.gov (United States)

    La Cognata, Marco; Del Zoppo, Antonio

    2011-08-01

    At temperatures (0.5-1.2) × 109 K, the 8Li + 4He → 11B+n reaction can allow for 12C and heavier element production in the framework of the inhomogeneous big bang nucleosynthesis. At temperatures (2.5-5) × 109 K, it can influence the production of seed nuclei, later burnt to heavier elements by means of rapid neutron capture reactions, during Type II supernova explosions. Previous determinations of the reaction rate show an untenable disagreement. In this work, a new reaction rate calculation is proposed for the intervals of astrophysical interest. This new recommendation turns out to be up to a factor of five larger than the most recent rate in the literature, thus enforcing the role of 8Li + 4He → 11B+n as a candidate for key astrophysical reactions. The analytical expression of the recommended reaction rate is given.

  3. THE 8Li(α, n)11B REACTION RATE AT ASTROPHYSICAL TEMPERATURES

    International Nuclear Information System (INIS)

    La Cognata, Marco; Del Zoppo, Antonio

    2011-01-01

    At temperatures (0.5-1.2) x 10 9 K, the 8 Li + 4 He → 11 B+n reaction can allow for 12 C and heavier element production in the framework of the inhomogeneous big bang nucleosynthesis. At temperatures (2.5-5) x 10 9 K, it can influence the production of seed nuclei, later burnt to heavier elements by means of rapid neutron capture reactions, during Type II supernova explosions. Previous determinations of the reaction rate show an untenable disagreement. In this work, a new reaction rate calculation is proposed for the intervals of astrophysical interest. This new recommendation turns out to be up to a factor of five larger than the most recent rate in the literature, thus enforcing the role of 8 Li + 4 He → 11 B+n as a candidate for key astrophysical reactions. The analytical expression of the recommended reaction rate is given.

  4. 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.

  5. Novel laboratory simulations of astrophysical jets

    Science.gov (United States)

    Brady, Parrish Clawson

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

  6. 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

  7. 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. A. A. Hakobyan. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 1 March 2016 pp 1. H α Velocity Fields and Galaxy Interaction in the Quartet of Galaxies NGC 7769, 7770, 7771 and 7771A · A. A. Yeghiazaryan T. A. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. G. C. Anupama. Articles written in Journal of Astrophysics and Astronomy. Volume 34 Issue 2 June 2013 pp 175-192. Generation of a Near Infra-Red Guide Star Catalog for Thirty-Meter Telescope Observations · Smitha Subramanian Annapurni Subramaniam Luc ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Niruj M. Ramanujam. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 37 Review. Fast Transients with the Square Kilometre Array and its Pathfinders: An Indian Perspective · Yashwant Gupta Poonam Chandra Manjari ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Pushpa Khare. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 1-2 June 2000 pp 19-27. Nature of the Background Ultraviolet Radiation Field at High Redshifts · Archana Samantaray Pushpa Khare · More Details Abstract Fulltext PDF.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. DEBADES BANDYOPADHYAY. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 36 Review. Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective · Sushan Konar Manjari Bagchi Debades ...

  12. 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. Biswajit Paul. Articles written in Journal of Astrophysics and Astronomy. Volume 28 Issue 4 December 2007 pp 175-184. Search for Orbital Motion of the Pulsar 4U 1626-67: Candidate for a Neutron Star with a Supernova Fall-back Accretion Disk.

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

    Indian Academy of Sciences (India)

    2016-01-27

    Journal of Astrophysics and Astronomy | News. Continuous Article Publication. Posted on January 27, 2016. Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Zhao Wen-juan. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 21 Research Article. Classification of Stellar Spectra with Fuzzy Minimum Within-Class Support Vector Machine · Liu Zhong-bao Song Wen-ai Zhang Jing ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. G. C. Stewart. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

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

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Astrophysics and Astronomy; Forthcoming articles. Forthcoming articles. Journal of Astrophysics and Astronomy. JOAA-D-17-00049. The Nature of ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Shanti Priya Devarapalli. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 3 September 2016 pp 18 Research Article. First Hα and Revised Photometric Studies of Contact Binary KP101231 · Shanti Priya Devarapalli Rukmini Jagirdar.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. PATRICK DAS GUPTA. Articles written in Journal of Astrophysics and Astronomy. Volume 39 Issue 1 February 2018 pp 14 Review. Collapsing supra-massive magnetars: FRBs, the repeating FRB121102 and GRBs · PATRICK DAS GUPTA NIDHI SAINI · More Details ...

  19. 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. John McKean. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 557-566. LOFAR and APERTIF Surveys of the Radio Sky: Probing Shocks and Magnetic Fields in Galaxy Clusters · Huub Röttgering ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Surajit Paul. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 533-536. Double Relics in the Outskirts of A3376: Accretion Flows Meet Merger Shocks? Ruta Kale K. S. Dwarakanath Joydeep Bagchi Surajit Paul.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sergey V. Ershkov. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 5 Research Article. Forbidden Zones for Circular Regular Orbits of the Moons in Solar System, R3BP · Sergey V. Ershkov · More Details Abstract Fulltext ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Samir Choudhuri. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 35 Review. Prospects of Measuring the Angular Power Spectrum of the Diffuse Galactic Synchrotron Emission with SKA1 Low · Sk. Saiyad Ali Somnath ...

  3. 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. T. Sivarani. Articles written in Journal of Astrophysics and Astronomy. Volume 34 Issue 1 March 2013 pp 5-17 Review Articles. Stellar Relics from the Early Galaxy · T. Sivarani · More Details Abstract Fulltext PDF. We reviewed the recent progress in ...

  4. 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. Himali Bhatt. Articles written in Journal of Astrophysics and Astronomy. Volume 34 Issue 4 December 2013 pp 393-429. X-ray Observations of Eight Young Open Star Clusters: I. Membership and X-ray Luminosity · Himali Bhatt J. C. Pandey K. P. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. Suryanarayana Sarma. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 33 Review Article. Charged Particle Monitor on the AstroSat Mission · A. R. Rao M. H. Patil Yash Bhargava Rakesh Khanna M. K. Hingar A. P. K. ...

  6. 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. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sarmistha Banik. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 36 Review. Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective · Sushan Konar Manjari Bagchi Debades Bandyopadhyay ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Shabnam Iyyani. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 30 Review. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors · Poonam Chandra G. C. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. N. Hari Prasad Rao. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 35 Review Article. Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations · R. Pandiyan S. V. Subbarao T.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Anshu Chauhan. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 35 Review Article. Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations · R. Pandiyan S. V. Subbarao T.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Journal of Astrophysics and Astronomy. Volumes & Issues. Volume 39. Issue 1. Feb 2018. Volume 38. Issue 1. Mar 2017; Issue 2. Jun 2017; Issue 3. Sep 2017; Issue 4. Dec 2017. Volume 37. Issue 1. Mar 2016; Issue 2. Jun 2016; Issue 3. Sep 2016; Issue 4. Dec 2016 ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Ananda Hota. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 41 Review. Tracking Galaxy Evolution Through Low-Frequency Radio Continuum Observations using SKA and Citizen-Science Research using ...

  13. 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. A. N. Ramaprakash. Articles written in Journal of Astrophysics and Astronomy. Volume 34 Issue 2 June 2013 pp 175-192. Generation of a Near Infra-Red Guide Star Catalog for Thirty-Meter Telescope Observations · Smitha Subramanian Annapurni ...

  14. 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. INDRANIL CHATTOPADHYAY. Articles written in Journal of Astrophysics and Astronomy. Volume 23 Issue 1-2 March-June 2002 pp 149-153. Radiatively Driven Winds from Effective Boundary Layer around Black Holes · Indranil Chattopadhyay ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. F. Reale. Articles written in Journal of Astrophysics and Astronomy. Volume 29 Issue 1-2 March-June 2008 pp 339-343. SphinX: A Fast Solar Photometer in X-rays · J. Sylwester S. Kuzin Yu. D. Kotov F. Farnik F. Reale · More Details Abstract Fulltext PDF. The scientific ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. U. S. Kamath. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 38 Review. Interstellar Medium and Star Formation Studies with the Square Kilometre Array · P. Manoj S. Vig G. Maheswar U. S. Kamath A. Tej.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Siddhartha Bhattacharyya. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 37 Review. Fast Transients with the Square Kilometre Array and its Pathfinders: An Indian Perspective · Yashwant Gupta Poonam Chandra ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Gireesh C. Joshi. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 4 December 2017 pp 72 Research Article. Identification of Stellar Sequences in Various Stellar Systems: ESO65-SC03, Teutsch 106, Turner 6 · Gireesh C. Joshi.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Gerard Vauclair. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 319-322 Session VII – Magnetoconvection & Stellar Activity. The Space Stellar Photometry Mission COROT: Asteroseismology and Search ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. ABHILASH R. SARWADE. Articles written in Journal of Astrophysics and Astronomy. Volume 39 Issue 1 February 2018 pp 11 Review. Study of X-ray transients with Scanning Sky Monitor (SSM) onboard AstroSat · M. C. RAMADEVI B. T. RAVISHANKAR ABHILASH R.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. C. Konar. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 471-474. A Multifrequency Study of Five Large Radio Galaxies · A. Pirya S. Nandi D. J. Saikia C. Konar M. Singh · More Details Abstract Fulltext PDF.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Siddharth Malu. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 529-532. Discovery of a Giant Radio Halo in a Massive Merging Cluster at = 0.443 · K. S. Dwarakanath Siddharth Malu Ruta Kale · More Details ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. A. K. Singh. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

  4. 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.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Ruta Kale. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 529-532. Discovery of a Giant Radio Halo in a Massive Merging Cluster at = 0.443 · K. S. Dwarakanath Siddharth Malu Ruta Kale · More Details Abstract ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Rajesh Mondal. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 29 Review. Modelling the 21-cm Signal from the Epoch of Reionization and Cosmic Dawn · T. Roy Choudhury Kanan Datta Suman Majumdar ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. V. Girish. Articles written in Journal of Astrophysics and Astronomy. Volume 26 Issue 2-3 June-September 2005 pp 203-211. HD 12098 and Other Results from Nainital–Cape Survey · V. Girish · More Details Abstract Fulltext PDF. Nainital;Cape Survey was started ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Abhishek Shukla. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 7 Research Article. Benford's Distribution in Extrasolar World: Do the Exoplanets Follow Benford's Distribution? Abhishek Shukla Ankit Kumar Pandey ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Essy Samuel. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. MOHAMMED HASAN. Articles written in Journal of Astrophysics and Astronomy. Volume 39 Issue 1 February 2018 pp 11 Review. Study of X-ray transients with Scanning Sky Monitor (SSM) onboard AstroSat · M. C. RAMADEVI B. T. RAVISHANKAR ABHILASH R.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Surya Ratna Prakash Dumpa. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 35 Review Article. Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations · R. Pandiyan S. V. ...

  12. 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. Monica Trasatti. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 589-598. LOFAR: Recent Imaging Results and Future Prospects · George Heald Michael R. Bell Andreas Horneffer André R. Offringa ...

  13. 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. A. A. Yeghiazaryan. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 1 March 2016 pp 1. H α Velocity Fields and Galaxy Interaction in the Quartet of Galaxies NGC 7769, 7770, 7771 and 7771A · A. A. Yeghiazaryan T. A. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Yash Bhargava. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 33 Review Article. Charged Particle Monitor on the AstroSat Mission · A. R. Rao M. H. Patil Yash Bhargava Rakesh Khanna M. K. Hingar A. P. K. Kutty J. P. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. S. V. Vadawale. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

  16. Statistical learning methods in high-energy and astrophysics analysis

    International Nuclear Information System (INIS)

    Zimmermann, J.; Kiesling, C.

    2004-01-01

    We discuss several popular statistical learning methods used in high-energy- and astro-physics analysis. After a short motivation for statistical learning we present the most popular algorithms and discuss several examples from current research in particle- and astro-physics. The statistical learning methods are compared with each other and with standard methods for the respective application

  17. Statistical learning methods in high-energy and astrophysics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, J. [Forschungszentrum Juelich GmbH, Zentrallabor fuer Elektronik, 52425 Juelich (Germany) and Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)]. E-mail: zimmerm@mppmu.mpg.de; Kiesling, C. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

    2004-11-21

    We discuss several popular statistical learning methods used in high-energy- and astro-physics analysis. After a short motivation for statistical learning we present the most popular algorithms and discuss several examples from current research in particle- and astro-physics. The statistical learning methods are compared with each other and with standard methods for the respective application.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. SANTABRATA DAS. Articles written in Journal of Astrophysics and Astronomy. Volume 23 Issue 1-2 March-June 2002 pp 143-147. Standing Shocks around Black Holes and Estimation of Outflow Rates · Santabrata Das Sandip K. Chakrabarti · More Details Abstract ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. T. Roy Choudhury. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 27 Review. Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations · Kanan K. Datta ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. M. Ramesh. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Chandreyee Maitra. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 36 Review. Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective · Sushan Konar Manjari Bagchi Debades ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sravani Vaddi. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 41 Review. Tracking Galaxy Evolution Through Low-Frequency Radio Continuum Observations using SKA and Citizen-Science Research using ...

  3. 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. J. Tao. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 1-2 March-June 2011 pp 67-71 Part 2. Blazar Observations in Infrared and Optical. Variability of Blazars · J. H. Fan Y. Liu Y. Li Q. F. Zhang J. Tao O. Kurtanidze.

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

    Indian Academy of Sciences (India)

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

  5. 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)

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Ankit Kumar Pandey. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 7 Research Article. Benford's Distribution in Extrasolar World: Do the Exoplanets Follow Benford's Distribution? Abhishek Shukla Ankit Kumar Pandey ...

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. M. Hiremath. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 263-264 Session V – Vector Magnetic Fields, Prominences, CMEs & Flares. Emergence of Twisted Magnetic Flux Related Sigmoidal ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. S. Dwarakanath. Articles written in Journal of Astrophysics and Astronomy. Volume 24 Issue 1-2 March-June 2003 pp 37-43. GMRT Detection of HI 21cm Associated Absorption towards the = 1.2 Red Quasar 3C 190 · C. H. Ishwara-Chandra K. S. Dwarakanath ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. S. Sarma. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

  11. 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. James Wicker. Articles written in Journal of Astrophysics and Astronomy. Volume 31 Issue 3 September 2010 pp 121-133. Oxygen Abundance Methods in SDSS: View from Modern Statistics · Fei Shi Gang Zhao James Wicker · More Details Abstract ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Samanwita Kar. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 3 September 2016 pp 17 Research Article. Possible Effect of the Earth's Inertial Induction on the Orbital Decay of LAGEOS · Ujjal Dey Samanwita Kar Amitabha Ghosh.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Frank Verbunt. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 3 September 2017 pp 40 Review Article. A New Look at Distances and Velocities of Neutron Stars · Frank Verbunt Eric Cator · More Details Abstract Fulltext PDF. We take a ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sagar Sethi. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 41 Review. Tracking Galaxy Evolution Through Low-Frequency Radio Continuum Observations using SKA and Citizen-Science Research using ...

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

  17. 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. Wahab Uddin. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 229-232 Session V – Vector Magnetic Fields, Prominences, CMEs & Flares. Analysis of the 9th November 1990 flare.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Liu Zhong-bao. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 2 June 2016 pp 12. Stellar Spectral Classification with Locality Preserving Projections and Support Vector Machine · Liu Zhong-bao · More Details Abstract Fulltext PDF.

  19. 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. H. M. Antia. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 353-356 Session VIII – Helioseismology. Temporal Variation of Large Scale Flows in the Solar Interior · Sarbani Basu H. M. ...

  20. 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. C. H. Ishwara-Chandra. Articles written in Journal of Astrophysics and Astronomy. Volume 24 Issue 1-2 March-June 2003 pp 37-43. GMRT Detection of HI 21cm Associated Absorption towards the = 1.2 Red Quasar 3C 190 · C. H. Ishwara-Chandra ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Sushan Konar. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 36 Review. Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective · Sushan Konar Manjari Bagchi Debades Bandyopadhyay ...

  2. 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. Rulee Baruah. Articles written in Journal of Astrophysics and Astronomy. Volume 30 Issue 3-4 September-December 2009 pp 165-175. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation · Rulee Baruah Kalpana ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. G. Arun. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 30 Review. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors · Poonam Chandra G. C. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. V. Navalkar. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. S. V. Subbarao. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 35 Review Article. Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations · R. Pandiyan S. V. Subbarao T. Nagamani ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. N. Vagshette. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. P. Priya. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna A. P. K. ...

  8. 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. Yang Chen. Articles written in Journal of Astrophysics and Astronomy. Volume 33 Issue 2 June 2012 pp 213-220. Star Formation Rate Indicators in Wide-Field Infrared Survey Preliminary Release · Fei Shi Xu Kong James Wicker Yang Chen Zi-Qiang ...

  9. 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. Sujan Sengupta. Articles written in Journal of Astrophysics and Astronomy. Volume 34 Issue 2 June 2013 pp 151-155. Spectro-Polarimetry of Self-Luminous Extrasolar Planets · Sujan Sengupta · More Details Abstract Fulltext PDF. Planets which are ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. N. J. Westergaard. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. H. Navalgund. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 29 Review Article. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance · K. P. Singh G. C. Stewart N. J. Westergaard S.

  12. 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. Leonard Strachan. Articles written in Journal of Astrophysics and Astronomy. Volume 29 Issue 1-2 March-June 2008 pp 167-170. Ultraviolet Spectroscopic Observations of Coronal Streamers in the SOHO Era · Leonard Strachan · More Details ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Somnath Bharadwaj. Articles written in Journal of Astrophysics and Astronomy. Volume 22 Issue 4 December 2001 pp 293-307. HI Fluctuations at Large Redshifts: I–Visibility correlation · Somnath Bharadwaj Shiv K. Sethi · More Details Abstract Fulltext PDF.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. BLESSY ELIZABETH BABY. Articles written in Journal of Astrophysics and Astronomy. Volume 39 Issue 1 February 2018 pp 11 Review. Study of X-ray transients with Scanning Sky Monitor (SSM) onboard AstroSat · M. C. RAMADEVI B. T. RAVISHANKAR ABHILASH ...

  15. 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. Avinash A. Deshpande. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 37 Review. Fast Transients with the Square Kilometre Array and its Pathfinders: An Indian Perspective · Yashwant Gupta ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. VIVEK KUMAR AGARWAL. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 32 Review Article. Early In-orbit Performance of Scanning Sky Monitor Onboard AstroSat · M. C. Ramadevi B. T. Ravishankar N. Sitaramamurthy G.

  17. 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. N. Kumar. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 3 September 2017 pp 57. Classical Orbital Paramagnetism in Non-equilibrium Steady State · Avinash A. Deshpande N. Kumar · More Details Abstract Fulltext PDF.

  18. 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. M. Ferricha-Alami. Articles written in Journal of Astrophysics and Astronomy. Volume 36 Issue 2 June 2015 pp 269-280. Tree Level Potential on Brane after Planck and BICEP2 · M. Ferricha-Alami A. Safsafi L. Lahlou H. Chakir M. Bennai.

  19. 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. J. O. Stenflo. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 451-457 Session XII – Conclusion. Summary Lecture · J. O. Stenflo · More Details Abstract Fulltext PDF. This summary ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Annie Baglin. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 319-322 Session VII – Magnetoconvection & Stellar Activity. The Space Stellar Photometry Mission COROT: Asteroseismology and Search ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Corot team. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 319-322 Session VII – Magnetoconvection & Stellar Activity. The Space Stellar Photometry Mission COROT: Asteroseismology and Search for ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. C. R. Subrahmanya. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 10 Review Article. The Ooty Wide Field Array · C. R. Subrahmanya P. K. Manoharan Jayaram N. Chengalur · More Details Abstract Fulltext PDF.

  3. 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. Jayaram Chengalur. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 475-476. The First Polarization Maps from the GMRT · Sanhita Joshi Jayaram Chengalur · More Details Abstract Fulltext PDF.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. P. Prasad. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 11 Review Article. The Receiver System for the Ooty Wide Field Array · C. R. Subrahmanya P. Prasad B. S. Girish R. Somashekar P. K. Manoharan A. K. Mittal.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Shashanka R. Gurumath. Articles written in Journal of Astrophysics and Astronomy. Volume 36 Issue 3 September 2015 pp 355-374. Solar Wind Associated with Near Equatorial Coronal Hole · M. Hegde K. M. Hiremath Vijayakumar H. Doddamani Shashanka R.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Rupal Basak. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 33 Review Article. Charged Particle Monitor on the AstroSat Mission · A. R. Rao M. H. Patil Yash Bhargava Rakesh Khanna M. K. Hingar A. P. K. Kutty J. P. ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Y. K. Arora. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. M. K. Hingar. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. D. S. Wamalwa. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 4 December 2017 pp 71 Research Article. Relativistic Dynamics in a Matter-Dominated Friedmann Universe · M. Langa D. S. Wamalwa C. Mito · More Details Abstract Fulltext ...

  10. 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. NAGENDRA KUMAR. Articles written in Journal of Astrophysics and Astronomy. Volume 29 Issue 1-2 March-June 2008 pp 243-248. Damping of Slow Magnetoacoustic Waves in an Inhomogeneous Coronal Plasma · Nagendra Kumar Pradeep ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Somak Raychaudhury. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 4 December 2017 pp 68 Research Article. Active Galactic Nucleus Feedback with the Square Kilometre Array and Implications for Cluster Physics and Cosmology.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Mahadev Pandge. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 4 December 2017 pp 68 Research Article. Active Galactic Nucleus Feedback with the Square Kilometre Array and Implications for Cluster Physics and Cosmology.

  13. 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.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. S. Seetha. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 1-2 June 2000 pp 29-38. X-ray Observation of XTE J2012+381 during the 1998 Outburst · S. Naik P. C. Agrawal B. Paul A. R. Rao S. Seetha Κ. Kasturirangan · More Details Abstract ...

  15. 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. Shibu K. Mathew. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 233-236 Session V – Vector Magnetic Fields, Prominences, CMEs & Flares. A Rapidly Evolving Active Region NOAA ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. T. Paul. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 6 Research Article. Short-Term H α Line Variations in Classical Be Stars: 59 Cyg and OT Gem · K. T. Paul S. B. Shruthi Annapurni Subramaniam · More Details ...

  17. 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. D. J. Saikia. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 471-474. A Multifrequency Study of Five Large Radio Galaxies · A. Pirya S. Nandi D. J. Saikia C. Konar M. Singh · More Details Abstract ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. Duorah. Articles written in Journal of Astrophysics and Astronomy. Volume 36 Issue 3 September 2015 pp 375-383. A Comparative Study on SN II Progenitors for the Synthesis of Li and B with the help of Neutrinos · N. Lahkar S. Kalita H. L. Duorah K. Duorah.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Abudusaimaitijiang Yisikandeer. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 3 September 2016 pp 22 Research Article. Velocity Distributions of Runaway Stars Produced by Supernovae in the Galaxy · Abudusaimaitijiang Yisikandeer ...

  20. 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. S. Kalita. Articles written in Journal of Astrophysics and Astronomy. Volume 36 Issue 3 September 2015 pp 375-383. A Comparative Study on SN II Progenitors for the Synthesis of Li and B with the help of Neutrinos · N. Lahkar S. Kalita H. L. Duorah ...

  1. 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. B. N. Dwivedi. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 397-401 Session X – Cycle Variation in the Quiet Corona & Coronal Holes. The EUV Spectrum of Sunspot Plumes ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. H. L. Duorah. Articles written in Journal of Astrophysics and Astronomy. Volume 30 Issue 3-4 September-December 2009 pp 165-175. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation · Rulee Baruah Kalpana Duorah H. L. Duorah.

  3. 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. Kalpana Duorah. Articles written in Journal of Astrophysics and Astronomy. Volume 30 Issue 3-4 September-December 2009 pp 165-175. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation · Rulee Baruah Kalpana ...

  4. 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. Larry D. Gardner. Articles written in Journal of Astrophysics and Astronomy. Volume 29 Issue 1-2 March-June 2008 pp 321-327. Next Generation UV Coronagraph Instrumentation for Solar Cycle-24 · John L. Kohl Rajmal Jain Steven R. Cranmer ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Viral Parekh. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 31 Review. Clusters of Galaxies and the Cosmic Web with Square Kilometre Array · Ruta Kale K. S. Dwarakanath Dharam Vir Lal Joydeep Bagchi Surajit ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Visweshwar Ram Marthi. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 1 March 2017 pp 12 Review Article. Prowess – A Software Model for the Ooty Wide Field Array · Visweshwar Ram Marthi · More Details Abstract Fulltext PDF.

  7. Interface between astrophysical datasets and distributed database management systems (DAVID)

    Science.gov (United States)

    Iyengar, S. S.

    1988-01-01

    This is a status report on the progress of the DAVID (Distributed Access View Integrated Database Management System) project being carried out at Louisiana State University, Baton Rouge, Louisiana. The objective is to implement an interface between Astrophysical datasets and DAVID. Discussed are design details and implementation specifics between DAVID and astrophysical datasets.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Duncan Lorimer. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 3 September 2017 pp 55 Review Article. Fast Radio Bursts · Akshaya Rane Duncan Lorimer · More Details Abstract Fulltext PDF. We summarize our current state of ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Rukmini Jagirdar. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 3 September 2016 pp 18 Research Article. First Hα and Revised Photometric Studies of Contact Binary KP101231 · Shanti Priya Devarapalli Rukmini Jagirdar · More Details ...

  10. 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. Chetana Jain. Articles written in Journal of Astrophysics and Astronomy. Volume 28 Issue 4 December 2007 pp 175-184. Search for Orbital Motion of the Pulsar 4U 1626-67: Candidate for a Neutron Star with a Supernova Fall-back Accretion Disk.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Prateek Sharma. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 31 Review. Clusters of Galaxies and the Cosmic Web with Square Kilometre Array · Ruta Kale K. S. Dwarakanath Dharam Vir Lal Joydeep Bagchi ...

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Abhirup Datta. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 27 Review. Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations · Kanan K. Datta ...

  13. Points of Interest: What Determines Interest Rates?

    Science.gov (United States)

    Schilling, Tim

    Interest rates can significantly influence people's behavior. When rates decline, homeowners rush to buy new homes and refinance old mortgages; automobile buyers scramble to buy new cars; the stock market soars, and people tend to feel more optimistic about the future. But even though individuals respond to changes in rates, they may not fully…

  14. Cosmic collaboration in an undergraduate astrophysics laboratory

    Science.gov (United States)

    Gunter, Ramona; Spiczak, Glenn; Madsen, James

    2010-10-01

    Lessons learned during the first offering of a lab component of an intermediate astrophysics course at the University of Wisconsin-River Falls are discussed. The course enrolled students from a variety of majors. Students worked in mixed-gender, mixed-major collaborative groups. They explored cosmic rays through hands-on, inquiry-based activities that took them from classic, fundamental discoveries to open-ended questions of their own design. We find that students divided their labor and brought the various parts of their research project together with little or no discussion regarding the various pieces and how they inform each other. Aspects of the lab design helped disrupt some typical gender dynamics in that men did not dominate group discussions. However, men did dominate the hands-on activities of the lab.

  15. 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.

  16. Astrophysical life extinctions what killed the dinosaurs?

    CERN Document Server

    Dar, Arnon

    1999-01-01

    Geological records indicate that the exponential diversification of marine and continental life on Earth in the past 500 My was interrupted by many life extinctions. They also indicate that the major mass extinctions were correlated in time with large meteoritic impacts, gigantic volcanic eruptions, sea regressions and drastic changes in global climate. Some of these catastrophes coincided in time. The astrophysical life extinction mechanisms which were proposed so far, in particular, meteoritic impacts, nearby supernova explosions, passage through molecular or dark matter clouds, and Galactic gamma/cosmic ray bursts cannot explain the time coincidences between these catastrophes. However, recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their passage near Earth could have generated gigantic tidal waves, large volcanic eruptions, ...

  17. Theoretically Palatable Flavor Combinations of Astrophysical Neutrinos.

    Science.gov (United States)

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

    2015-10-16

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

  18. New Prospects in High Energy Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Blandford, Roger; /KIPAC, Menlo Park

    2011-11-15

    Recent discoveries using TeV, X-ray and radio telescopes as well as Ultra High Energy Cosmic Ray arrays are leading to new insights into longstanding puzzles in high energy astrophysics. Many of these insights come from combining observations throughout the electromagnetic and other spectra as well as evidence assembled from different types of source to propose general principles. Issues discussed in this general overview include methods of accelerating relativistic particles, and amplifying magnetic field, the dynamics of relativistic outflows and the nature of the prime movers that power them. Observational approaches to distinguishing hadronic, leptonic and electromagnetic outflows and emission mechanisms are discussed along with probes of the velocity field and the confinement mechanisms. Observations with GLAST promise to be very prescriptive for addressing these problems.

  19. General relativity with applications to astrophysics

    CERN Document Server

    Straumann, Norbert

    2004-01-01

    This text provides a comprehensive and timely introduction to general relativity The foundations of the theory in Part I are thoroughly developed together with the required mathematical background from differential geometry in Part III The six chapters in Part II are devoted to tests of general relativity and to many of its applications Binary pulsars are studied in considerable detail Much space is devoted to the study of compact objects, especially to black holes This includes a detailed derivation of the Kerr solution, Israel's proof of his uniqueness theorem, and derivations of the basic laws of black hole physics The final chapter of this part contains Witten's proof of the positive energy theorem The book addresses undergraduate and graduate students in physics, astrophysics and mathematics It is very well structured and should become a standard text for a modern treatment of gravitational physics The clear presentation of differential geometry makes it also useful for string theory and other fields of ...

  20. Astrophysical black holes in screened modified gravity

    International Nuclear Information System (INIS)

    Davis, Anne-Christine; Jha, Rahul; Muir, Jessica; Gregory, Ruth

    2014-01-01

    Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect

  1. Astrophysical black holes in screened modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Anne-Christine; Jha, Rahul; Muir, Jessica [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom); Gregory, Ruth, E-mail: acd@damtp.cam.ac.uk, E-mail: r.a.w.gregory@durham.ac.uk, E-mail: r.jha@damtp.cam.ac.uk, E-mail: jlmuir@umich.edu [Centre for Particle Theory, South Road, Durham, DH1 3LE (United Kingdom)

    2014-08-01

    Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect.

  2. Interstellar Polycyclic Aromatic Compounds and Astrophysics

    Science.gov (United States)

    Hudgins, Douglas M.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role polycyclic aromatic compounds (PAC) in the interstellar medium (ISM). Twenty years ago, the notion of an abundant population of large, carbon rich molecules in the ISM was considered preposterous. Today, the unmistakable spectroscopic signatures of PAC - shockingly large molecules by previous interstellar chemistry standards - are recognized throughout the Universe. In this paper, we will examine the interstellar PAC model and its importance to astrophysics, including: (1) the evidence which led to inception of the model; (2) the ensuing laboratory and theoretical studies of the fundamental spectroscopic properties of PAC by which the model has been refined and extended; and (3) a few examples of how the model is being exploited to derive insight into the nature of the interstellar PAC population.

  3. Relativistic astrophysics and cosmology a primer

    CERN Document Server

    Hoyng, Peter

    2006-01-01

    This book offers a succinct and self-contained treatment of general relativity and its application to neutron stars, black holes, gravitational waves and cosmology, at an intermediate level. The required mathematical concepts are introduced informally, following geometrical intuition as much as possible. The approach is theoretical, but there is ample discussion of observational aspects and instrumental issues where appropriate. Topical issues such as the Gravity Probe B mission, and the physics of interferometer detectors of gravitational waves and the angular power spectrum of the Cosmic Microwave Background are included. The book is written for advanced undergraduates and beginning graduate students in (astro)physics. The reader is assumed to be familiar with linear algebra and analysis, ordinary differential equations, special relativity, and basic thermal physics, but prior knowledge of differential geometry and general relativity is not required. Containing 140 exercises with extensive hints for their s...

  4. Studies of High Energy Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Nitz, David F [Michigan Technological University; Fick, Brian E [Michigan Technological University

    2014-07-30

    This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in the Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.

  5. Analogue Hawking radiation from astrophysical black-hole accretion

    International Nuclear Information System (INIS)

    Das, Tapas K

    2004-01-01

    We show that spherical accretion onto astrophysical black holes can be considered as a natural example of an analogue system. We provide, for the first time, an exact analytical scheme for calculating the analogue Hawking temperature and surface gravity for general relativistic accretion onto astrophysical black holes. Our calculation may bridge the gap between the theory of transonic astrophysical accretion and the theory of analogue Hawking radiation. We show that the domination of the analogue Hawking temperature over the actual Hawking temperature may be a real astrophysical phenomenon, though observational tests of this fact will at best be difficult and at worst might prove to be impossible. We also discuss the possibilities of the emergence of analogue white holes around astrophysical black holes. Our calculation is general enough to accommodate accreting black holes with any mass

  6. Parallel Information Phenomena of Biology and Astrophysics

    Science.gov (United States)

    Frieden, B. Roy; Soffer, Bernard H.

    The realms of biology and astrophysics are usually regarded as distinct, to be studied within individual frameworks. However, current searches for life in the universe, and the expectation of positive results, are guiding us toward a unification of biology and astrophysics called astrobiology. In this chapter the unifying aspect of Fisher information is shown to form two bridges of astrobiology: (i) In Section 5.1 quarter-power laws are found to both describe attributes of biology, such as metabolism rate, and attributes of the cosmos, in particular its universal constants, (ii) In Section 5.2 we find that the Lotka-Volterra growth equations of biology follow from quantum mechanics. Both these bridges follow, ultimately, from the extreme physical information EPI principle and, hence, are examples of the “cooperative” universe discussed in Chapter 1. That is, the universe cooperates with our goal of understanding it, through participatory observation. The participatory aspect of the effect (i) is the observation of biological and cosmological attributes obeying quarter-power laws. In the Lotka-Volterra quantum effect (ii) the participation is the observation of a general particle member that undergoes scattering by a complex potential. This potential causes the growth or depletion of the particle population levels to obey Lotka-Volterra equations. Effectively, the interaction potentials of a standard Hartree view of the scattering process become corresponding fitness coefficients of the L-V growth equations. The two ostensibly unrelated effects of scattering and biological growth are thereby intimately related; out of a common flow of Fisher information to the observer.

  7. 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

  8. 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

  9. 78 FR 66384 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-11-05

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... INFORMATION: The agenda for the meeting includes the following topics: --Astrophysics Division Update...

  10. 75 FR 2893 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-01-19

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... and Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA... the room. The agenda for the meeting includes the following topics: --Astrophysics Division Update...

  11. 76 FR 5405 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2011-01-31

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topics: --Astrophysics Division Update --Update from the James Webb Space...

  12. 75 FR 51116 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-08-18

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... the meeting includes the following topics: --Astrophysics Division Update --2010 Astronomy and...

  13. 2nd Iberian Nuclear Astrophysics Meeting on Compact Stars

    Science.gov (United States)

    Perez-Garcia, M. Angeles; Pons, Jose; Albertus, C.

    2012-02-01

    ORGANIZING COMMITTEE Dr M Ángeles Pérez-García (Área Física Teórica-Universidad de Salamanca & IUFFYM) Dr J A Miralles (Universidad de Alicante) Dr J Pons (Universidad de Alicante) Dr C Albertus (Área Física Nuclear-Universidad de Salamanca & IUFFYM) Dr F Atrio (Área Física Teórica-Universidad de Salamanca & IUFFYM) PREFACE The second Iberian Nuclear Astrophysics meeting was held at the University of Salamanca, Spain on 22-23 September 2011. This volume contains most of the presentations delivered at this international workshop. This meeting was the second in the series following the previous I Encuentro Ibérico de Compstar, held at the University of Coimbra, Portugal in 2010. The main purpose of this meeting was to strengthen the scientific collaboration between the participants of the Iberian and the rest of the southern European branches of the European Nuclear Astrophysics network, formerly, COMPSTAR. This ESF (European Science Foundation) supported network has been crucial in helping to make a broader audience for the the most interesting and relevant research lines being developed currently in Nuclear Astrophysics, especially related to the physics of neutron stars. It is indeed important to emphasize the need for a collaborative approach to the rest of the scientific communities so that we can reach possible new members in this interdisciplinary area and as outreach for the general public. The program of the meeting was tailored to theoretical descriptions of the physics of neutron stars although some input from experimental observers and other condensed matter and optics areas of interest was also included. The main scientific topics included: Magnetic fields in compact stars Nuclear structure and in-medium effects in nuclear interaction Equation of state: from nuclear matter to quarks Importance of crust in the evolution of neutron stars Computational simulations of collapsing dense objects Observational phenomenology In particular, leading

  14. Evidence for Astrophysical Muon Neutrinos from the Northern Sky with IceCube

    Science.gov (United States)

    Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Tjus, J. Becker; Becker, K.-H.; Beiser, E.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Brown, A. M.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Christy, B.; Clark, K.; Classen, L.; Coenders, S.; Cowen, D. F.; Silva, A. H. Cruz; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; Dumm, J. P.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fahey, S.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Fuchs, T.; Glagla, M.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Gier, D.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Goodman, J. A.; Góra, D.; Grant, D.; Gretskov, P.; Groh, J. C.; Groß, A.; Ha, C.; Haack, C.; Ismail, A. Haj; Hallgren, A.; Halzen, F.; Hansmann, B.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hellwig, D.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfe, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jero, K.; Jurkovic, M.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kiryluk, J.; Kläs, J.; Klein, S. R.; Kohnen, G.; Kolanoski, H.; Konietz, R.; Koob, A.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, G.; Kroll, M.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Middlemas, E.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Paul, L.; Pepper, J. A.; de los Heros, C. Pérez; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Pütz, J.; Quinnan, M.; Rädel, L.; Rameez, M.; Rawlins, K.; Redl, P.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Richter, S.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Sabbatini, L.; Sander, H.-G.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schimp, M.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schukraft, A.; Schulte, L.; Seckel, D.; Seunarine, S.; Shanidze, R.; Smith, M. W. E.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Tosi, D.; Tselengidou, M.; Unger, E.; Usner, M.; Vallecorsa, S.; van Eijndhoven, N.; Vandenbroucke, J.; van Santen, J.; Vanheule, S.; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallraff, M.; Wandkowsky, N.; Weaver, C.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wichary, C.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Zoll, M.; IceCube Collaboration

    2015-08-01

    Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of νe and ντ charged-current and neutral-current (cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35 000 muon neutrinos from the Northern sky is extracted from data taken during 659.5 days of live time recorded between May 2010 and May 2012. While this sample is composed primarily of neutrinos produced by cosmic ray interactions in Earth's atmosphere, the highest energy events are inconsistent with a hypothesis of solely terrestrial origin at 3.7 σ significance. These neutrinos can, however, be explained by an astrophysical flux per neutrino flavor at a level of Φ (Eν)=9.9-3.4+3.9×10-19 GeV-1 cm-2 sr-1 s-1(Eν/1 00 TeV ) -2 , consistent with IceCube's Southern-Hemisphere-dominated result. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed. We find a spectral index of 2.2-0.2+0.2 , which is also in good agreement with the Southern Hemisphere result.

  15. 360-degree videos: a new visualization technique for astrophysical simulations, applied to the Galactic Center

    Science.gov (United States)

    Russell, Christopher

    2018-01-01

    360-degree videos are a new type of movie that renders over all 4π steradian. Video sharing sites such as YouTube now allow this unique content to be shared via virtual reality (VR) goggles, hand-held smartphones/tablets, and computers. Creating 360-degree videos from astrophysical simulations not only provide a new way to view these simulations due to their immersive nature, but also yield engaging content for outreach to the public. We present our 360-degree video of an astrophysical simulation of the Galactic center: a hydrodynamics calculation of the colliding and accreting winds of the 30 Wolf-Rayet stars orbiting within the central parsec. Viewing the movie, which renders column density, from the location of the supermassive black hole gives a unique and immersive perspective of the shocked wind material inspiraling and tidally stretching as it plummets toward the black hole. We also describe how to create such movies, discuss what type of content does and does not look appealing in 360-degree format, and briefly comment on what new science can be extracted from astrophysical simulations using 360-degree videos.

  16. Evidence for Astrophysical Muon Neutrinos from the Northern Sky with IceCube.

    Science.gov (United States)

    Aartsen, M G; Abraham, K; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Ahrens, M; Altmann, D; Anderson, T; Archinger, M; Arguelles, C; Arlen, T C; Auffenberg, J; Bai, X; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Tjus, J Becker; Becker, K-H; Beiser, E; BenZvi, S; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Börner, M; Bos, F; Bose, D; Böser, S; Botner, O; Braun, J; Brayeur, L; Bretz, H-P; Brown, A M; Buzinsky, N; Casey, J; Casier, M; Cheung, E; Chirkin, D; Christov, A; Christy, B; Clark, K; Classen, L; Coenders, S; Cowen, D F; Silva, A H Cruz; Daughhetee, J; Davis, J C; Day, M; de André, J P A M; De Clercq, C; Dembinski, H; De Ridder, S; Desiati, P; de Vries, K D; de Wasseige, G; de With, M; DeYoung, T; Díaz-Vélez, J C; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Ehrhardt, T; Eichmann, B; Euler, S; Evenson, P A; Fadiran, O; Fahey, S; Fazely, A R; Fedynitch, A; Feintzeig, J; Felde, J; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Fuchs, T; Glagla, M; Gaisser, T K; Gaior, R; Gallagher, J; Gerhardt, L; Ghorbani, K; Gier, D; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grant, D; Gretskov, P; Groh, J C; Groß, A; Ha, C; Haack, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hansmann, B; Hanson, K; Hebecker, D; Heereman, D; Helbing, K; Hellauer, R; Hellwig, D; Hickford, S; Hignight, J; Hill, G C; Hoffman, K D; Hoffmann, R; Holzapfe, K; Homeier, A; Hoshina, K; Huang, F; Huber, M; Huelsnitz, W; Hulth, P O; Hultqvist, K; In, S; Ishihara, A; Jacobi, E; Japaridze, G S; Jero, K; Jurkovic, M; Kaminsky, B; Kappes, A; Karg, T; Karle, A; Kauer, M; Keivani, A; Kelley, J L; Kemp, J; Kheirandish, A; Kiryluk, J; Kläs, J; Klein, S R; Kohnen, G; Kolanoski, H; Konietz, R; Koob, A; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krings, K; Kroll, G; Kroll, M; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Lanfranchi, J L; Larson, M J; Lesiak-Bzdak, M; Leuermann, M; Leuner, J; Lünemann, J; Madsen, J; Maggi, G; Mahn, K B M; Maruyama, R; Mase, K; Matis, H S; Maunu, R; McNally, F; Meagher, K; Medici, M; Meli, A; Menne, T; Merino, G; Meures, T; Miarecki, S; Middell, E; Middlemas, E; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Niederhausen, H; Nowicki, S C; Nygren, D R; Obertacke, A; Olivas, A; Omairat, A; O'Murchadha, A; Palczewski, T; Paul, L; Pepper, J A; de Los Heros, C Pérez; Pfendner, C; Pieloth, D; Pinat, E; Posselt, J; Price, P B; Przybylski, G T; Pütz, J; Quinnan, M; Rädel, L; Rameez, M; Rawlins, K; Redl, P; Reimann, R; Relich, M; Resconi, E; Rhode, W; Richman, M; Richter, S; Riedel, B; Robertson, S; Rongen, M; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Sabbatini, L; Sander, H-G; Sandrock, A; Sandroos, J; Sarkar, S; Schatto, K; Scheriau, F; Schimp, M; Schmidt, T; Schmitz, M; Schoenen, S; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Seckel, D; Seunarine, S; Shanidze, R; Smith, M W E; Soldin, D; Spiczak, G M; Spiering, C; Stahlberg, M; Stamatikos, M; Stanev, T; Stanisha, N A; Stasik, A; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Strotjohann, N L; Sullivan, G W; Sutherland, M; Taavola, H; Taboada, I; Ter-Antonyan, S; Terliuk, A; Tešić, G; Tilav, S; Toale, P A; Tobin, M N; Tosi, D; Tselengidou, M; Unger, E; Usner, M; Vallecorsa, S; van Eijndhoven, N; Vandenbroucke, J; van Santen, J; Vanheule, S; Veenkamp, J; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Wallraff, M; Wandkowsky, N; Weaver, C; Wendt, C; Westerhoff, S; Whelan, B J; Whitehorn, N; Wichary, C; Wiebe, K; Wiebusch, C H; Wille, L; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, D L; Xu, X W; Xu, Y; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Zoll, M

    2015-08-21

    Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of ν(e) and ν(τ) charged-current and neutral-current (cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35,000 muon neutrinos from the Northern sky is extracted from data taken during 659.5 days of live time recorded between May 2010 and May 2012. While this sample is composed primarily of neutrinos produced by cosmic ray interactions in Earth's atmosphere, the highest energy events are inconsistent with a hypothesis of solely terrestrial origin at 3.7σ significance. These neutrinos can, however, be explained by an astrophysical flux per neutrino flavor at a level of Φ(E(ν))=9.9(-3.4)(+3.9)×10(-19)  GeV(-1) cm(-2) sr(-1) s(-1)(E(ν)/100  TeV(-2), consistent with IceCube's Southern-Hemisphere-dominated result. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed. We find a spectral index of 2.2(-0.2)(+0.2), which is also in good agreement with the Southern Hemisphere result.

  17. Interests and corruption

    Directory of Open Access Journals (Sweden)

    Joković Milica S.

    2017-01-01

    Full Text Available This paper analyses the connection of interests and corruption, especially corruption and political interests. It first considers the notion of interest, i.e. its meanings and significance, both for an individual and for a society. It presents the classification if interests by Albion Woodbury Small. A special emphasis is given to the encounter of different interests as the beginning of clash between humans. The paper analyses individual, special and general interests, as well as their relations. The paper also analyses two levels of conflict of interest: the conflict between public and private interest and the conflict between interests within the public offices. The relation of interests in society and politics is solved in the best way by adopting laws, i.e. by introducing the rule of law into political order. Without that the interest orientation of politicians can easily end up in abuse and illegality. In turn, abuses and illegalities open the possibilities for various kinds of corruptive acts.

  18. Solar Astrophysics, Interferometry, and Coronagraphy at DomeC/Concordia

    Science.gov (United States)

    Damé, L.; Amans, J.-P.; Dournaux, J.-L.; Koutchmy, S.; Lamy, P.; Preumont, A.

    Excellent seeing, coronal conditions, and very low IR thermal background are qualities of the Dome C/Concordia station site that will allow unique solar astrophysics science. We review the science case for inner corona observations (onset of the coronal heating mechanism still poorly understood) and the promises of high angular resolution to disentangle the possible mechanisms at work between waves, convection, and reconnection in this particularly magnetically structured solar atmosphere between the high chromosphere and inner corona. For coronagraphy, IR and high resolution possibilities, Dome C is a case by itself between classical ground-based sites and space opportunities. Telescopes from 50 cm (coronagraphy oriented) to 4 m (full high resolution advantage including IR access) are proposed to benefit from these remarkable observing capabilities. Using 3×O50 cm off-axis telescopes, we first propose a medium size facility (1.4 m equivalent telescope) for very high resolution access, ADSIIC (Antarctica Demonstrator of Solar Interferometric Imaging & Coronagraphy), before the ultimate 9-telescope Solar Facility equivalent to a 4 m diameter telescope: A-FOURMI (Antarctica 4 m Interferometer). Finally, 30 m tower designs and their logistics using standard containers and elementary elements of 6 m maximum length, are presented and discussed. These towers are indeed of general interest also for the other optical and IR telescopes intended for Dome C/Concordia, allowing to get over most of the turbulent ground layer and to reach the best possible permanent seeing conditions (better than half an arcsec).

  19. TeV Particle Astrophysics 2010, Booklet of abstracts

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  20. Nuclear Physics Constraints on the Characteristics of Astrophysical Thermonuclear Flashes

    International Nuclear Information System (INIS)

    Truran, James W

    2012-01-01

    We review the nuclear physics that is associated with the outbursts of Type Ia (thermonuclear) supernova explosions and with the thermonuclear runaway events that define the outbursts of both classical novae and recurrent novae. We describe how distinguishing characteristics of these two classes of astrophysical explosion are strongly dependent both upon fuel ignition in degenerate matter and upon the rates of critical charged-particle reaction rates and weak interaction rates. In this centennial celebration of the important contributions of Rutherford and his collaborators to our understanding of the structure of the nucleus of an atom, it is quite interesting to note the evolution of the α-particle scattering experiments described in Rutherford's seminal paper (Rutherford 1911) to current studies of α-particle induced reactions and their defining roles in studies of stellar, nova, and supernova nucleosynthesis. We identify and discuss for example: (1) the manner in which (α, p) reactions in proximity to the Z = N line carry the major flows from 12 C and 16 O to 56 Ni in Type Ia supernovae; and (2) the critical role of the 15 O(α, γ) 19 Ne reaction in possibly effecting 'breakout' of the Hot CNO cycles at the highest temperatures achievable in Classical Novae. In this contribution, we first review the current status our understanding of Type Ia supernova events and then that of Classical Novae.