bluuebunny/crossref_metadata_2025_split huggingface dataset:
Archiving and retrieval of data from the International Ultraviolet Explorer (IUE) mission
Authors: Warren W. H. , Alderman D. F. 
Published: July 2016

AbstractThe data base of IUE spectra available for dissemination to the scientific community presently contains approximately 22,000 separate images. Due to storage space and computer processing time limitations, it was decided to store the data on high density (6250 bpi) specially formatted tapes and to retrieve and reconvert them to the originally supplied format upon request. The archival/retrieval system for the data and an automatic data entry system for creation and maintenance of an indexing data base are described. Suggestions are made for the use of standard formats for future image data storage, retrieval and dissemination.
Le Centre de Donnees des Amas de Galaxies
Authors: Fernandez A. , Mathez G. , Mazure A. , Nottale L. , Rothenflug R. 
Published: July 2016

AbstractA Cluster of Galaxies Data Center is in the process of being settled. Its aim will be to collect the data presently scattered in the literature, concerning clusters of galaxies, in all wavelength ranges. We describe its diverse entries and we discuss some specific problems and its possible future utilization.
Geneva photometric boxes. IV. A refined method for direct access
Authors: Nicolet Bernard 
Published: July 2016

AbstractIn the Geneva photometry, a photometric box around a so-called central star is the set of stars having almost the same colours as this central star.For the most current applications, it is useful to construct the boxes of a few hundred stars. A method allowing to obtain these boxes rapidly is described. It is based on socalled direct access square files. A FORTRAN routine on a UNIVAC 1160 computer is widely used at the Geneva Observatory. The principles described in this paper may be easily adapted to build square files and to write routines in evolved languages for most computers.Other applications of square files are also outlined.
The Zelenchuk 6m Telescope (BTA) of the USSR Academy of Sciences
Authors: Ioannisiani B.K. , Neplokhov E.M. , Kopylov I.M. , Rylov V.S. , Snezhko L.I. 
Published: July 2016

AbstractA description is given of the alt-azimuth mounted 6-meter telescope (BTA) installed in the North Caucasus at an altitude of 2070m above sea level and about 40km to the south of Zelenchukskaya village. Some details of the BTA instrumentation and the local astroclimate are also reported.
Statistical test of the distribution of perihelion points and its implication for cometary origin
Authors: Yabushita S. 
Published: July 2016

AbstractThe distribution of perihelion points of long-period comets is known to cluster towards the solar apex, and some authors ascribe it to north-south asymmetry in the distribution of observers. Validity or otherwise of this alleged selection effect is tested by randomly picking up the same number of perihelia in the southern (δ < 0) as those in the northern (δ > 0) hemisphere. It is shown that the observed clustering cannot be ascribed to the asymmetry of observers. Further, 67 comets which are new in Oort’s sense are tested similary. The character of their distribution is similar to that of all the known comets. It appears difficult to interpret the clustering in terms of a recent stellar disturbance of the Oort cloud.
Dynamical interactions of the solar system with massive nebulae
Authors: Napier W.M. 
Published: July 2016

AbstractThe effects of encounters with massive nebulae on the long-period comet population are examined, paying particular attention to the uncertainties in the data. An earlier conclusion, that the long-period comet system is dynamically unstable, is upheld. Whether replenishment by unbinding from a dense inner comet cloud is a viable hypothesis awaits detailed modelling, but a qualitative discussion is given which argues tentatively against it. If comets occur in molecular clouds, however, their capture into temporarily bound Solar System orbits is a natural consequence of close encounters for realistic velocities and potentials. A large disturbance or capture may have occurred a few Myr ago as the Sun emerged from the Orion spiral arm.
The dynamical history of comet Halley
Authors: Yeomans Donald K. 
Published: July 2016

AbstractThe history of the attempts to predict the motion of comet Halley is outlined and the importance of the so-called nongravitational forces acting upon this comet is emphasized. Recent orbital work of the International Halley Watch Astrometry Network is reviewed. Comet Halley’s transverse nongravitational parameter is positive and nearly constant with time suggesting that the comet is in direct rotation without precession of the spin pole. The nongravitational effects are consistent with the vaporization of water ice from the comet’s nucleus and long term integrations suggest that the comet has been in its present orbit for at least 16,000 years and probably much longer.
Photographic Observations of the Inner Zodiacal Light Aboard Saliout 7
Authors: Nikolsky G. , Koutchmy S. , Lamy P.L. , Nesmjanovich I.A. 
Published: July 2016

AbstractColor photographs of the inner Zodiacal Light were obtained aboard Saliout 7 with Kodak Ekta 400. Absolute calibrations were performed in-Flight with attenuated Sun light. The photometric analysis was carried out in three colors and corrections were introduced for the 01 emission of the F layers. The brightness of the Zodiacal Light along the ecliptic is found in good agreement with published data while its color is found slightly redder than the Sun. Its out-of-ecliptic variation coincides neither with the fan nor the ellipsoidal model; the photometric axis is found near the projection of the orbital plane of Venus.
An Observational Search for the Schuerman Dust Arcs
Authors: Giovane F. , Weinberg J.L. , Mann H.M. , Oliver J.P. 
Published: July 2016

AbstractLarge-scale interplanetary dust arcs were predicted by Schuerman (1980) to be associated with the planets. An arc, if one exists, would produce asymmetries on opposite sides of the Gegenschein during the Earth’s two passages through the arc each year. A brief description is given of Gegenschein/arc observing constraints, of future viewing opportunities, and of the results of a test program conducted from Mt. Haleakala, Hawaii, in Jan/Feb 1984 when the Earth encountered the arc associated with Saturn.
A Coronascanner for a Sun Oriented Space Mission
Authors: Koutchmy S. , Lamy P.L. 
Published: July 2016

AbstractThe quantitative study of the solar corona between 3 and 20 R⊙ is still a challenging task. Inherent difficulties are the proximity of the Sun and the still bright inner corona (< 3 R⊙), the low brightness of the outer corona and the low contrast of possible structures. A spinning, externally-occulted coronograph having its field-of-view limited to a sector of the corona presents several advantages over conventional coronographs for this study such as higher rejection of stray light and azimuthal uniformity over the whole field-of-view. Such an instrument could address the following aspects of the F-corona:– photopolarimetry and colorimetry– ellipticity, axis of symmetry– temporal/spatial variations– equatorial enhancements (rings)– local component.
Influence of Surface Roughness on Scattering Patterns
Authors: Mukai S. , Mukai T. 
Published: July 2016

AbstractThe influence of surface roughness on scattering properties of light is examined in terms of our previous mathematical method (Mukai et al. 1982). We found that albedo for single reflected light increases with an increase of surface roughness. In addition, a higher order of reflection light becomes effective for stronger rough particles.
Selection Effects Against Small Comets
Authors: Zook H.A. , Fernández J.A. , Grün E. 
Published: July 2016

AbstractThere are three factors that inhibit detecting small comets relative to large comets: 1. They must pass closer to the Earth than large comets to be detected. 2. The resulting higher angular velocity for nearby comets means that, at comparable apparent magnitudes, there is less time available to discover a small comet relative to a large comet. 3. Small comets physically decay and vanish faster than do large comets. With these three factors, it can be shown that if the small comet input distribution gi (Rn) in varies as , where Rn is the nuclear radius of the comet, then the observed distribution will vary as
Interaction of the Cometary Dust with the Solar Wind and Cometary Plasma
Authors: Ip W.-H. , Kimura H. , Liu C.-P. 
Published: July 2016

AbstractAlong the lines of previous studies on the cometary dust-plasma interaction processes, we evaluate the electromagnetic effect of submicron dust in the coma and in the dust tail. The possible occurence of electrostatic disruption of charged dust in the ion tail is also discussed from theoretical and observational points of view. The relevance of these processes to the formation of striae in the dust tails of several comets is addressed and the conclusion is made that trajectory study of the submicron dust in the striae must take into account the action of the interplanetary electric field.
Optical and Photoelectric Properties of Materials of Astrophysical Interest
Authors: Quemerais A. , Seignac A. , Priol M. , Lefèvre J. 
Published: July 2016

AbstractThe charge of cosmic grains can be calculated if the optical constants, the photoelectric yields and the photoelectron energy distributions for a large range of energy of incident photons are known. Our measurements are made on several materials which are possible constituents of interstellar and interplanetary dusts. We present here our results for fused quartz, iron and carbon.
Laboratory Simulation of Chemical Interactions of Accelerated Ions with Dust and Ice Grains
Authors: Rössler K. 
Published: July 2016

AbstractEnergetic ions or atoms in space may undergo hot chemical reactions upon penetration into interplanetary or interstellar dust grains, ice layers, cometary matter, and surfaces of planetary moons. The mechanistic pathways can be different from those of classical ion molecule interactions, photolytical and radiolytical processes. The kinetic energy of the hot reactant facilitates endothermic reactions and those with high energy of activation, among them atom-molecule interactions. The conditions of hot cosmic chemistry are simulated in laboratory experiments in order to obtain insight into the nature of chemical products and the reaction mechanisms of their formation. This paper reviews the methods of ion implantation, nuclear recoil in situ, nuclear recoil implantation, secondary knock-on processes and computer simulation of collision cascades. Carbon and nitrogen impact in frozen H2O, NH3 and CH4 is shown to lead to the formation and radiolytic permutation of a series of organic molecules, among them e.g. formaldehyde, methanol, methylamine, cyanamide, formamidine and guanidine which may act as precursors for biomolecules.
Summary and Conclusion of the Colloquium
Authors: Lamy P.L. 
Published: July 2016

There is now a satisfactory convergence of the observational results for the absolute intensity of the zodiacal light for elongations larger than 20° to 30°. They are still discrepancies affecting the data for the F-corona but after carefully scrutinizing available data, Koutchmy and Lamy could obtain an axy-asymmetric non-spherical model for the equatorial and polar regions which satisfactorily bridges to the zodiacal light. However, a closer examination reveals several points of concern:
i)the gradient of the brightness which is of utmost importance for retrieving the phase function of interplanetary dust: the “Hawaï” data (Misconi and Weinberg), the PCN data (Nikolsky et al.) and the classical data of Dumont and Sanchez are in disagreement;ii)a lack of data for the inner zodiacal light;iii)insufficient out-of-ecliptic data; the on-going analysis of the “Hawaï” data (which benefits from an improved reduction method) and of the “South Africa” data will help partly remedy this situation. A consensus appears to be reached on the near solar color of the zodiacal light or, to be more precise, a slight reddening down to 2000 Å. The inner zodiacal light and the F-corona are clearly redder than the Sun. Some structure near 2800 Å reported by Feldman et al. is certainly worth of further investigation. Ultraviolet observations of Comet Halley may well provide adequate opportunities. The situation of the polarization of the zodiacal light is less satisfactory as large discrepancies persist. Of major importance for the properties of the dust grains are the behaviours at small and large scattering angles - in particular, the shape of the negative branch - as well as the angle of maximum polarization and its magnitude. The polarization is certainly color dependent but the present data are insufficient for a clear-cut conclusion.
Derivation of the Ionization Balance for Iron XIV/XXV and XXIII/XXIV Using Solar X-Ray Data
Authors: Antonucci E. , Dodero M.A. , Gabriel A.H. , Tanaka K. 
Published: July 2016

The relative concentrations of different ionization stages of iron are measured using the spectral emission of plasmas formed during solar flares. This is an extension of a study on the ionization balance of heavy elements, initiated with the analysis of calcium solar spectra (Antonucci et al., 1984). The data consist of a large set of iron spectra in the wavelength range from 1.84 to 1.88 Å, detected during the recent maximum of activity with the X-ray Polychromator Bent Crystal Spectrometer (BCS) on the NASA Solar Maximum Mission satellite and on the Soft X-ray Crystal Spectrometer (SOX) on the Hinotori satellite.At the low densities typical of the solar corona, in the steady state the ionization balance of an element is a function of the plasma electron temperature. Hence, it can be measured for plasmas of known temperature and in slowly varying physical conditions, and in most cases, solar flare plasmas can be considered to be in such conditions.
The Relevancy of Magnetically Confined Plasmas - Tokamak and Mirror - for Atomic Spectroscopy And Astrophysical Plasma Diagnostics
Authors: Finkenthal M. 
Published: July 2016

This talk presented the magnetic confinement experiments from a different angle, i.e. as laboratory sources which allow the study of various problems in such fields as atomic physics and astrophysics.Tokamak and magnetic mirror plasmas have properties which make them particularly suitable for basic atomic physics experiments; they are stable over long intervals of time and have wide ranges of electrom densities and temperatures. Also, models on which electron density and temperature diagnostics are based in astrophysical research can be checked since these quantities are accurately measured by independent non-spectroscopic methods.
Observation of Ionization of Laser Excited Atoms by Synchrotron Radiation
Authors: Bizau J.M. , Wuilleumier F. , Gerard P. , Dhez P. , Carré B. , Spiess G. , Ederer D.L. , Picqué J.L. , LeGouet J.L. , Keller J.C. , Koch P. 
Published: July 2016

We have begun a program to measure oscillator strengths of autoionizing resonances that result from a transition in the VUV between a laser excited initial state and a final state in which a core electron is promoted. These measurements demonstrate a new technique to combine synchrotron radiation, laser pumping, and photoelectron spectroscopy.Measurements of the energy positions of autoionizing resonances have been honed to a fine art over the past 50 years. Total cross section measurements and the parameters that describe autoionizing resonances have been determined. Most of these studies have been made from the dipole allowed ground state. Recently autoionizing resonances have been observed from excited initial states and from ion initial states. We have heard several talks, at this meeting which described some of this type of research. In the measurements to be described in this paper, laser radiation is combined with synchrotron radiation, as shown schematicaly in Figure 1, to study the photoionization from excited initial states to continuum final states or to autoionizing final states. Continuum radiation from the Aneau de Collisions d’Orsay (ACO), which is installed at the Universite de Paris-Sud, in Orsay France, is monochromatized by a toroidal grating monochromator (TGM) and is focused by a toroidal output mirror on to a weakly collimated sodium beam emanating from a furnace mounted on the axis of a cylinderical mirror analyzer (CMA). This electron spectrometer is used to study the kinetic energy distribution of the ejected photoelectrons produced by the interaction of the photon beam with the focused synchrotron radiation.
Critical Compilations of Atomic Transition Probabilities
Authors: Martin G.A. , Fuhr J.R. , Wiese W.L. 
Published: July 2016

The NBS Data Center on Atomic Transition Probabilities is nearing completion of a critical compilation of atomic transition probability data on allowed and forbidden transitions in the elements scandium through nickel in all stages of ionization. This compilation constitutes a revision of a series of smaller NBS compilations published in recent years in the Journal of Physical and Chemical Reference Data. Upon completion of this project, work on updating of an even earlier compilation covering the elements hydrogen through neon will be initiated.The world literature on atomic transition probabilities is collected and catalogued on an ongoing basis by the Data Center. A master reference list is maintained, and annotated bibliographies are issued as the number of new articles in the literature and the resources of the Center permit. A computerized bibliographic database system is being developed to enhance the capability for handling bibliographical information in the NBS data centers on transition probabilities, line shapes and shifts, and energy levels. Development of a computerized database of critically evaluated numerical data on atomic spectroscopic quantities is planned for the future.
Dielectronic Recombination of Highly Stripped Argon Ions: Theoretical Calculations and Direct Observations in an Ebis Source
Authors: Loulergue M. , Dubau J. , Briand J.P. , Charles P. , Laurent H. 
Published: July 2016

The dielectronic recombination is one of the most important atomic processes in highly ionised plasmas. It corresponds to the simultaneous capture of a free electron and excitation of an ion, i.e.It is a collisionally resonant process which occurs only at the energy of the corresponding autoionisation electron. We present here a preliminary theoretical analysis of the results of an experiment using a novel technique in which it is possible to observe the interaction of a given ion with an electron at a given energy and so to measure the differential dielectronic cross section corresponding to each resonant level of this ion.
New Methods in Development of X-Ray Optics for Plasma Diagnostics of Laser - Produced Plasma
Authors: Hudec R. , Valníček B. 
Published: July 2016

A new technology was developed for manufacturing of precise and low-cost X-ray grazing incidence microscopic optics.Imaging experiments represent one of the main directions in the Czechoslovak X-ray astronomy program. The Space Research Department of the Astronomical Institute of the Czechoslovak Academy of Sciences in Ondřejov has been active in the development of X-ray mirrors since 1970. We have participated in 7 space X-ray imaging experiments. 6 experiments were flown onboard the Vertical 8, 9 and 11 rockets in the years 1979, 1981 and 1983 (Hudec et al. 1984a), one experiment was flown onboard the Soviet orbital station Salyut 7 in the year 1982 (Valníček et al. 1983 and Hudec et al. 1984b). The experiments represent both small solar X-ray imaging telescopes and big stellar X-ray telescope.
Neutrino Transport in a Type II Supernova Environment
Authors: Schinder Paul J. , Shapiro Stuart L. 
Published: July 2016

AbstractWe discuss the full problem of neutrino transport in the context of a Type II supernova environment. We describe the “standard model” of Type II supernova, which involves the core collapse and core bounce of an 8 — 20M⊙ star. Although the shock produced in the standard model is supposed to expel the outer layers of the star, this does not happen in the best numerical collapse calculations without considerable numerical tweaking, if at all. In this model, neutrino transport plays an important role. We describe the weakness of the best transport approximation currently used in collapse calculations, the flux-limited diffusion approximation. We investigate the effect of a full transport approach by constructing two different types of model atmospheres, with conditions chosen to closely approximate conditions found in full collapse calculations. The first model is to construct equilibrium plane-parallel hydrostatic neutrino atmospheres. The second is to solve the equations of neutrino hydrodynamics for a spherical shell of matter, with a piston and a source of neutrinos at the lower boundary. We describe in detail the neutrino interactions which are important in the supernova problem. We present the equations of neutrino hydrodynamics and neutrino hydrostatics which are solved in the two models, and emphasize the differences between photon transport and neutrino transport. We describe briefly a “toy” model, the neutrino Eddington atmosphere, which highlights the differences between photon and neutrino atmospheres. We present the results of our model atmosphere calculations for a few selected cases of interest. Finally, we summarize alternatives and extensions to the standard model which are of current interest and may hold the answer to the Type II supernova problem. However, the delicate balance between competing effects suggest that a rigorous calculation of neutrino transport will be required to obtain a definitive answer.
Observations of Compact X-Ray Sources
Authors: Tanaka Y. 
Published: July 2016

This paper reviews the present status of observations of compact X-ray sources with emphasis on the aspects related to radiation hydrodynamics, based on the recent observational results, in particular those from the Japanese X-ray astronomy satellite Tenma. The main feature of Tenma is a large-area gas scintillation proportional counters (GSPC) with energy resolution twice that of ordinary proportional counters, which can yield information on energy spectrum superior in quality to previous results. We shall deal here only with those galactic X-ray sources in which the compact object is a neutron star or possibly a black hole, and exclude white dwarf sources.There exist more than one hundred bright X-ray sources in our galaxy in the luminosity range 1036−1038 ergs/sec. They are most probably binaries involving a neutron star or, in some cases, possibly a black hole. The high luminosities of these sources are explained in terms of the large gravitaional energy release by matter accreting from the companion star to the compact object.