(NASA-TM-103451; NAS 1.15:103451; PB90-233305) Avail: NTIS HC/MF A03 CSCL 03B In the absence of accretion torques, a pulsar in a binary system will spin down due to electromagnetic dipole radiation and the spin-down power will drive a wind of relativistic electron-positron pairs. Winds from pulsars with short periods will prevent any subsequent accretion but may be confined by the companion star atmosphere, wind, or magnetosphere to form a standing shock. The authors investigate the possibility of particle acceleration at such a pulsar wind shock and the production of very high energy (VHE) and ultra high energy (UHE) gamma rays from interactions of accelerated protons in the companion star's wind or atmosphere. They find that in close binaries containing active pulsars, protons will be shock accelerated to a maximum energy dependent on the pulsar spin-down luminosity. If a significant fraction of the spin-down power goes into particle acceleration, these systems should be sources of VHE and possibly UHE gamma rays. The authors discuss the application of the pulsar wind model to binary sources such as Cygnus X-3, as well as the possibility of observing VHE gamma-rays from known binary radio pulsar systems. N91-10817# Los Alamos National Lab., NM. GRA A SEMI-ANALYTICAL MODEL OF STELLAR FLARES Roger A. Kopp and Giannina Poletto (Osservatorio Astrofisico di Arcetri, Florence, Italy) 1990 4 p Presented at the Armagh International Colloquium on Surface Inhomogenities, Armagh, Ireland, 24-27 Jul. 1990 Submitted for publication Sponsored in part by Consiglio Nazionale delle Ricerche; Florence Univ., Italy; and Italian Space Agency (Contract W-7405-eng-36) (DE90-016434; LA-UR-90-2903; CONF-9007158-1) Avail: NTIS HC/MF A01 We present a simplified 'point' model to describe the hydrodynamic response of coronal loop plasma to the sudden release of energy which occurs at the time of a flare. Our simplification allows the full set of partial differential equations for energy, momentum, and mass conservation to be replaced by a corresponding set of ordinary differential equations for the plasma properties averaged over the loop volume. The temporal profiles of plasma temperature, density, and velocity are calculated over a time interval long enough to ensure that pre-flare conditions are re-established. The model is used for the interpretation of stellar flare data. In particular, we derive a set of representative loop geometries and flare energy inputs which allows us to reproduce the high emission measures typically inferred from observations of stellar flares. DOE N91-10818# Los Alamos National Lab., NM. Theoretical Div. NUCLEAR STRUCTURE CALCULATIONS FOR ASTROPHYSICAL APPLICATIONS Peter Moeller, J. Rayford Nix, Karl-Ludwig Kratz, and W. Michael Howard (Lawrence Livermore National Lab., CA.) 15 Aug. 1990 12 p Presented at the International Symposium on Nuclear Astrophysics: Nuclei in the Cosmos, Vienna, Austria, 18-22 Jun. 1990 Submitted for publication (Contract W-7405-eng-36) (DE90-016433; LA-UR-90-2909; CONF-9006212-2) Avail: NTIS HC/MF A03 Relative to other fields of physics, astrophysics is probably unique in its requirement that a very large number of physical environments be modeled to achieve a satisfactory description of the phenomena under study. The dynamics of the cosmos is governed by interactions that span a vast range, from subnucleon, nucleon and nuclear distances to distances affected by the gravitational interactions, which extend over the width of a galaxy and beyond, to the edge of the universe. It is the nuclear processes that provide much of the energy that drives the macroscopic behavior of the cosmos. Through this energy release the behavior on the very small scale is coupled to the very large-scale behavior. On the nuclear level, cross sections, nuclear decay energies and nuclear decay paths are but a few examples of quantities that are of paramount importance in astrophysical models. Because nuclei of extreme composition, quite different from what can be studied on earth, exist in stellar environments, an understanding of the nuclear structure properties of these nuclei can only be obtained through theoretical means. This presents a continuing, stimulating challenge to the nuclear-physics community. Here we present calculated results on such diverse properties as nuclear energy levels, ground-state masses and shapes, (beta)-decay properties and fission-barrier heights. Our approach to these calculations is to use a unified theoretical framework within which the above properties can all be studied. The results are obtained in the macroscopic-microscopic approach in which a microscopic nuclear-structure single-particle model with extensions is combined with a macroscopic model, such as the liquid-drop model. DOE N91-10819# Consiglio Nazionale delle Ricerche, Frascati (Italy). Ist. di Fisica dello Spazio Interplanetario. UV OBSERVATIONS OF HERBIG-HARO OBJECTS ASSOCIATED WITH BIPOLAR MOLECULAR OUTFLOWS: HH 7, HH 11 AND HH 29 Murray Cameron (University Coll., London, England) and Rene Liseau Apr. 1990 44 p Submitted for publication Sponsored in part by Swedish Board for Space Activities; Deutche Akademie der Wissenschaften; and Royal Society (IFSI-90-9; ETN-90-97792) Avail: NTIS HC/MF A03 Observations carried out by the International Ultraviolet Explorer (IUE) of the shock exited nebulae HH 7, HH 11 and HH 29 are presented. The individual UV observations of these objects appear very faint. An alternative extraction method different from that commonly used for the reduction of IUE data is described. The method is applied to the data in image space therefore not distorting the photometry. The reliability of this method is demonstrated. Data from the observation of the Herbig-Haro stars is presented and discussed. ESA N91-10820# Consiglio Nazionale delle Ricerche, Frascati (Italy). A. Felici and M. Storini Apr. 1990 17 p The interaction of an interplanetary shock with the terrestrial magnetic field produces geomagnetic sudden storm commencements. Rapid variations observed in terrestrial magnetographs recorded from 1975 to 1986 are collected. They are to be used in a preliminary evaluation of the sudden storm commencement event which occurred during solar cycle N.21. The data is useful for studies connected to solar-terrestrial physics in the absence of solar wind measurements. ESA 91 LUNAR AND PLANETARY EXPLORATION Includes planetology; and manned and unmanned flights. For spacecraft design or space stations see 18 Spacecraft Design, Testing and Performance. N91-10821 Toledo Univ., OH. Avail: Univ. Microfilms Order No. DA9015889 By obtaining spectra of 33 09-B2 near-main sequence stars, and by calculating a grid of theoretical stellar atmospheres, the fundamental properties were determined and mass loss was examined in a select sample of stars. Most stars are cluster members and photometrically constant; all are single stars and none exhibit emission lines. The optical observations were made with the coude spectrograph at the 2.1 m and coude feed telescopes at Kitt Peak National Observatory; the data have a signal-to-noise ratio of around 100, and resolutions ranging from .11 to 5 A. High dispersion ultraviolet observations were made with the IUE satellite; additional data were obtained from the IUE archives. Effective temperatures, surface gravities, and projected rotational velocities in the program stars were determined by comparing selected lines of H, He I, and Mg II with a grid of models calculated with a non-LTE, line-blanketed code (Anderson, 1985, 1989). The code was updated to include bound-bound and bound-free transitions of H, He I and II, C II-III, N II-IV, O II-IV, and Mg II. A method of opacity sampling was developed to account for blanketing due to the elements with atomic numbers 21 to 28. Mass loss was characterized by a parameter describing the asymmetry of the C IV doublet. Roughly half the program stars show evidence of a wind-winds appear to switch on at around 26000 to 27000 K at a log g of 4, where the equivalent width of the model C IV doublet is 2.5 to 3 A. The degree of asymmetry of the CIV doublet shows a clear monotonic increase with temperature; it also shows a monotonic trend with luminosity. No abundance anomalies in He, N, and C are apparent. (PB90-182338; SGD-545-Pt-1; ISSN-0038-0911; LC-79-640375) Avail: NTIS HC/MF A08 CSCL 03B A detailed index for 1989 is presented. Data for December 1989 include: solar-terrestrial environment, IUWDS alert periods (advance and worldwide), solar activity indices, solar flares, solar radio emission, and Stanford mean solar magnetic field. Data for November 1989 include: solar active regions, sudden ionospheric disturbances, solar radio spectral observations, cosmic ray measurements by neutron monitor, and geomagnetic indices. Late Data of geomagnetic indices from September to October 1989 include: solar active regions-Carrington Rotation 1821 October 1989. Author N91-10823# National Geophysical Data Center, Boulder, CO. SOLAR-GEOPHYSICAL DATA NUMBER 546, FEBRUARY 1990. PART 1: (PROMPT REPORTS). DATA FOR JANUARY 1990, DECEMBER 1989, AND LATE DATA H. E. Coffey Feb. 1990 164 p (PB90-195363; SGD-546-Pt-1) Avail: NTIS HC/MF A08 CSCL 09B A detailed index is presented for 1989 and 1990. Data for January 1990 include: Solar terrestrial environment; IUWDS alert periods (advance and worldwide); Solar activity indices; Solar flares; Solar radio emission, and Stanford mean solar magnetic field. Data for December 1989 include: Solar active regions; Sudden ionospheric disturbances; Solar radio spectral observations; Cosmic ray measurements by neutron monitor; and Geomagnetic indices. Late data include: Cosmic ray measurements by neutron monitor; and Reprint of Halftone page Kitt Peak solar magnetic field synoptic chart for Nov. 1989. Author N91-10824# National Geophysical Data Center, Boulder, CO. SOLAR-GEOPHYSICAL DATA NUMBER 546, FEBRUARY 1990. PART 2: (COMPREHENSIVE REPORTS). DATA FOR AUGUST 1989 AND MISCELLANEOUS H. E. Coffey Feb. 1990 184 p (PB90-195371; SGD-546-Pt-2) Avail: NTIS HC/MF A09 CSCL 03B A detailed index is presented for 1989 and 1990. Data for August 1989 include: Solar flares; solar radio bursts at fixed frequencies; Solar x ray radiation from GOES satellite; Mass ejections from the sun; and Active prominences and filaments. Miscellaneous data include: Meudon carte synoptique Carrington rotations 1816 and 1817 for June 1989; and Interplanetary solar particles. Author N91-10825# National Geophysical Data Center, Boulder, CO. SOLAR-GEOPHYSICAL DATA NUMBER 547, MARCH 1990. PART 1: (PROMPT REPORTS). DATA FOR FEBRUARY, JANUARY 1990, AND LATE DATA H. E. Coffey Mar. 1990 153 p (PB90-208877; SGD-547-Pt-1) Avail: NTIS HC/MF A08 CSCL 03B A detailed index is presented for 1989 and 1990. Data for February 1990 include: Solar terrestrial environment; IUWDS alert periods (advance and worldwide); Solar activity indices; Solar flares; Solar radio emission; and Stanford mean solar magnetic field. Data for January 1990 include: Solar active regions; Sudden ionospheric disturbances; Solar radio spectral observations; Cosmic ray measurements by neutron monitor; and Geomagnetic indices. Late data include: Solar radio emission January 1990; Geomagnetic indices Oct. to Nov. 1989; and Solar geophysical data questionnaire results. Author N91-10826# National Geophysical Data Center, Boulder, CO. SOLAR-GEOPHYSICAL DATA NUMBER 547, MARCH 1990. PART 2: (COMPREHENSIVE REPORTS). DATA FOR SEPTEMBER 1989 AND MISCELLANEOUS H. E. Coffey Mar. 1990 147 p (PB90-208885; SGD-547-Pt-2) Avail: NTIS HC/MF A07 CSCL 03B A detail index is presented for 1989 and 1990. Data for September 1989 include: Solar flares; Solar radio bursts at fixed frequencies; Solar x ray radiation from GOES satellite; Mass ejections from the sun; and Active prominences and filaments. Miscellaneous data include: Meudon carte synoptique; Carrington rotation 1818 July 1989; Solar proton events affecting the Earth's environment (GOES satellites) Jan. 1976 to Jan. 1990; and Solar Author geophysical data questionnaire results. N91-10827 Arizona Univ., Tucson. THE DEVELOPMENT OF THE CONTINUOUS Ross Debner Rosenwald 1989 461 p Two new analysis methods for solar seismology are developed. Called the continuous orthonormalization (CON) and adjoint methods, their use enables both solar eigenfrequencies and eigenfrequency sensitivities to be computed more accurately and efficiently than with existing methods. The CON method integrates an eighth-order nonlinear system of ordinary differential equations (ODES) which defines the linear adiabatic nonradial oscillation modes of the Sun. All normal modes of oscillation are treated identically, regardless of their type or their predominant location inside the Sun. The adjoint method integrates a related eighth-order linear inhomogeneous system of ODEs. From the resultant solution, an eigenfrequency's partial derivatives with respect to an extensive set of solar model parameters may be computed simultaneously. Extensive numerical tests confirm the validity of the two new methods. Eigenfrequencies obtained via the CON method have seven significant digits and match within 1 percent the eigenfrequencies obtained via finite difference or mesh approaches. Eigenfrequency sensitivities obtained via the adjoint method match with 2 percent the results obtained by explicitly perturbing the solar model parameters and recomputing the eigenfrequencies. The usefulness and power of the two new methods are demonstrated by applying them to the solution of an elementary solar inversion problem. A sample solar model's f-mode frequencies are iteratively driven into agreement with an observed set of f-mode frequencies. Adjoint sensitivity results are used to alter solar model parameters within hundreds of radial bins. Dissert. Abstr. (PB90-214487; NCAR/CT-124) Avail: NTIS HC/MF A15 CSCL 03B Observations of Stokes spectral profiles enable the magnetic fields on the Sun's surface to be determined. Inversion is the process whereby the profiles are reduced to magnetic field vectors. One of the most robust, accurate, and rapid methods available for inversion uses the least squares fitting of analytical Stokes profiles. As this technique is suitable for the automated reduction of large sets of data, it was adopted for use with the Advanced Stokes Polarimeter, presently under development. The limitations of inversion by analytical profile fitting were not firmly established. Confident analysis of magnet field vectors depends upon the precise interpretation of reduced data. A framework is introduced which allows such an assessment to be made. The magnetofluid-static sunspon models presented provide a self-consistent range of physical conditions similar to those in sunspots. Inversion can then be carried out on Stokes profiles synthesized from these known realistic conditions. Author (NASA-CR-187337; JPL-Publ-90-34; NAS 1.26:187337) Avail: NTIS HC/MF A03 CSCL 03B Solar radio emission could seriously interfere with observations made by a low frequency (1 to 10 MHz) array in space. International Sun-Earth Explorer (ISEE-3) radio data were used to determine solar emission level. The results indicate that solar emission should seriously disturb less than ten percent of the data, even during the years of solar maximum. Thus it appears that solar emission should not cause a disastrous loss of data. The information needed to design procedures to excise solar interference from the data produced by any low-frequency array is provided. Author (DE90-016495; LA-UR-90-2764; CONF-9006261-1) Avail: NTIS HC/MF A01 It has been suggested by Parker Sturrock et al., and others that the corona may be stochastically heated, on spatial scales at or below current instrumental resolution limits, by a continuous succession of many small flarelike events commonly referred to as nanoflares. In this paper we extend a semi-analytical point model developed previously for solar compact flares, to include gravitational plasma downfall during the late decay phase. Applying the model to conditions representative of nanoflares allows us to predict the temporal variation of average plasma properties in such events and should ultimately facilitate a calculation of the spectral characteristics of a nanoflare-heated corona. DOE N91-10831# Texas Univ., Austin. PROPAGATION OF MAGNETOACOUSTIC WAVES IN THE SOLAR ATMOSPHERE WITH RANDOM INHOMOGENEITIES OF DENSITY AND MAGNETIC FIELDS M. Ryutova (Academy of Sciences, USSR, Novosibirsk ), M. Kaisig, and T. Tajima Aug. 1990 18 p (Contract DE-FG05-80ET-53088) (DE90-017616; DOE/ET-53088/446; IFSR-446) Avail: NTIS HC/MF A03 Effects of strong and random inhomogeneities of the magnetic fields, plasma density, and temperature in the solar atmosphere on the properties of magnetoacoustic waves of arbitrary amplitudes are studied. The procedure which allows one to obtain the averaged equation containing the nonlinearity of a wave, dispersion properties of a system, and dissipative effects is described. It is shown that depending on the statistical properties of the medium, different scenarios of wave propagation arise: in the predominance of dissipative effects the primary wave is damped away in the linear stage and the efficiency of heating due to inhomogeneities is much greater than that in homogeneous medium. Depending on the interplay of nonlinear and dispersion effects, the process of heating can be afforded through the formation of shocks or through the storing of energy in a system of solitons which are later damped away. Our computer simulation supports and extends the above theoretical investigations. In particular the enhanced dissipation of waves due to the strong and random inhomogeneities is observed and this is more pronounced for shorter waves. DOE N91-10832*# National Aeronautics and Space Administration. (NASA-TM-103516; NAS 1.15:103516) Avail: NTIS HC/MF A03 CSCL 03B The objective was to develop the capability for and coaligned observations of the structure and evolution of the Sun's magnetic field at two different heights in the solar atmosphere: the photosphere, which is the lowest region observable with optical telescopes; and the chromosphere, which lies just above the photosphere and is the region where the magnetic field dominates the gas motion so that a well-ordered structure governed by the field is observed. By obtaining this three-dimensional picture of the solar magnetic field, a better understanding can be developed of the magnetic forces that produce and control the dynamic, high-energy phenomena occurring in the solar atmosphere that can affect the entire heliosphere, including the terrestrial environment. Author N91-10833# Consiglio Nazionale delle Ricerche, Rome (Italy). Ist. di Fisica dello Spazio Interplanetario. G. Villoresi, F. Re, F. Signoretti, N. L. Zangrilli, and N. lucci (Rome (IFSI-90-15; ETN-90-97797) Avail: NTIS HC/MF A04 The preliminary five minute pressure corrected data of total neutron intensity and of the intensities of multiplicities one to greater than or equal to eight are presented in the form of daily plots. The data was recorded during March 1990 by the Rome 17-NM-64. Ways in which the data can be used during the forthcoming solar activity maximum are discussed. For each monitor section the various multiplicities are measured in a gate time of 1200 microseconds. The attenuation coefficients for atmospheric pressure change correction are given. ESA N91-10834# Consiglio Nazionale delle Ricerche, Rome (Italy). Ist. di Fisica dello Spazio Interplanetario. PLOTS OF THE 5-MINUTE NEUTRON MONITOR INTENSITY AND MULTIPLICITIES RECORDED BY THE ROME 17-NM64, APRIL 1990 G. Villoresi, F. Re, F. Signoretti, N. L. Zangrilli, and N. lucci (Rome Univ., Italy) Frascati, Italy May 1990 63 p (IFSI-90-18; ETN-90-97800) Avail: NTIS HC/MF A04 The preliminary five minute pressure corrected data of total N91-10835 Manchester Univ. (England). David W. Murphy 1988 284 p Avail: Univ. Microfilms Order No. BRD-88730 The radio properties of a complete sample of 94 core-dominated radio sources, observed with the VLA, are examined to determine whether these properties are consistent with the hypothesis, known as the unified scheme, that core-dominated quasars are intrinsically the same object as lobe-dominated quasars, but just viewed with their radio jets oriented closer to the line of sight. High dynamic range maps are produced by combining data sets from different VLA arrays, frequencies and epochs. Various distributions of parameters are compared with the predictions of the relativistic beaming models. In particular it is found that the data cannot be fitted with a single relativistic jet velocity but require a large dispersion in this parameter. This dispersion only agrees with VLBI data on transverse motions if Hubble's constant is nearer to 100 than 50 km s(exp-1) Mpc(exp-1). Furthermore the large projected linear sizes of the quasars cannot be explained by large intrinsic bend angles but require that these sources have large intrinsic linear sizes. Evidence is also found from the radio properties of the BL Lacs in the sample that they are not quasars oriented with their radio jets at very small angles to the line of sight, as has been proposed by various authors. The radio morphology and spectra of the empty field sources indicate that they may belong to the 'compact VLBI double' class of radio source. Finally published optical and x-ray data on quasars are examined and evidence is found for the existence of a beamed component in radio sources which exhibits itself in all wavebands from the radio to the x-ray regime. The presence of such a component has obvious repercussions for understanding of Active Galactic Nuclei. Dissert. Abstr. (DE90-016467; LA-UR-90-2631; CONF-900367-2) Avail: NTIS HC/MF A03 Intrinsic properties of neutrinos as deduced from cosmological, astrophysical, and laboratory experiments are reviewed. Bounds on magnetic moments and theoretical models which yield large moments but small masses are briefly discussed. The MSW solution to the solar neutrino problem is reviewed in light of the existing data from the Cl-37 and Kamiokande II experiments. The combined data disfavor the adiabatic solution and tend to support either the large angle solution or the nonadiabatic one. In the former case the Ga-71 signal will be suppressed by the same factor as for Cl-37, and in the latter case the suppression factor could be as DOE large as 10 or more. N91-10837# Consiglio Nazionale delle Ricerche, Rome (Italy). ON THE AUTOREGRESSION METHODS APPLIED TO THE S. Pase, M. Parisi, S. Sparnocchia (Rome Univ., Italy ), E. Salusti, and M. Storini Frascati, Italy Oct. 1989 29 p (IFSI-89-19; ETN-90-97780) Avail: NTIS HC/MF A03 Application of autoregressive methods to temporal variations of the cosmic ray nucleonic component is presented. The hourly data registered in Rome (Italy) in the NM-64 detector with a threshold rigidity of 6.2 GV during the period 1977 to 1982 is examined. The results obtained through analysis of two Forbush decreases are discussed in detail. These events on February 14, 1978 and July 10, 1982 are shown to be best analyzed using a nonlinear autoregressive model rather than a linear model. The decrease amplitude and temporal recovery phase are easily reconstructed without the aid of external physical parameters. ESA N91-10838# Consiglio Nazionale delle Ricerche, Rome (Italy). COSMIC-RAY INTENSITY INCREASE OBSERVED ON E. G. Cordado, N. lucci (Rome Univ., Italy ), and M. Storini Frascati, Data obtained in Chile with the standard neutron monitor are reported. The Santiago 6NM-64 monitor has a geomagnetic cut-off rigidity of about 11 GV. A ground-level solar cosmic ray event registered on September 29, 1989 is analyzed in detail. Possible studies connected with such a rare event are suggested. The importance of such studies in developing a better understanding of solar-interplanetary-terrestrial relations is stressed. Comparisons between the readings recorded at the Rome and Japan based ESA stations are presented. 99 GENERAL No abstracts in this category. N91-10836# Los Alamos National Lab., NM. NON-ACCELERATOR EXPERIMENTS S. P. Rosen 25 Jul. 1990 17 p Presented at the 1st International Symposium on Particles, Strings, and Cosmology, Boston, MA, 27-31 Mar. 1990 Submitted for publication (Contract W-7405-eng-36) |