bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do Relativistic Electrons Either Gain or Lose Energy, Outside of Extragalactic Nuclei?
Authors: Rudnick Lawrence , Katz-Stone Debora M. , Anderson Martha C. 
Published: July 2016

AbstractIn the generally accepted models of high-luminosity extragalactic radio sources, the relativistic electron distribution evolves significantly outside of its source in the galactic nucleus; synchrotron losses occur throughout the source, and the harder (flatter) spectra seen in the hot spots are one indicator of relativistic particle acceleration. Our reanalysis and interpretation of the Carilli et al. (1991) data on Cygnus A, on the other hand, showed no evidence for evolution of the electron distribution function, and no evidence of the universally assumed injection power-law distribution. Having found a spectrum that describes an entire source, we have also introduced the technique of correcting synchrotron maps for frequency-dependent effects. In this way, a partial deconvolution of the underlying physical parameters is possible. In Cygnus A, this correction procedure led to the dominance of a hitherto unrecognized structure, an edge-brightened channel girdled by rings. We briefly discuss some implications of this work and our plans to continue this line of investigation.Subject headings: acceleration of particles — galaxies: individual (Cygnus A) — galaxies: nuclei — radiation mechanisms: nonthermal — radio continuum: galaxies
Time-Dependent Simulation of Cosmic-Ray Shocks, Including Alfvén Transport
Authors: Jones T. W. 
Published: July 2016

AbstractTime evolution of plane, cosmic-ray modified shocks has been simulated numerically for the case with parallel magnetic fields. Computations were done in a “three-fluid” dynamical model incorporating cosmic-ray and Alfvén-wave energy transport equations. Nonlinear feedback from the cosmic rays and Alfvén waves is included in the equation of motion for the underlying plasma, as is the finite propagation speed and energy dissipation of the Alfvén waves. Exploratory results confirm earlier, steady state analyses that found these Alfvén transport effects to be potentially important when the upstream Alfvén speed and gas sound speeds are comparable. As noted earlier, Alfvén transport effects tend to reduce the transfer of energy through a shock from gas to energetic particles. These studies show as well that the timescale for modification of the shock is altered in nonlinear ways. It is clear, however, that the consequences of Alfvén transport are strongly model dependent and that both advection of cosmic rays by the waves and dissipation of wave energy in the plasma will be important to model correctly when quantitative results are needed. Comparison is made between simulations based on a constant diffusion coefficient and more realistic diffusion models allowing the diffusion coefficient to vary in response to changes in Alfvén wave intensity. No really substantive differences were found between them.Subject headings: cosmic rays — MHD — shock waves
The All Sky Automated Survey (ASAS-3) System – Its Operation and Preliminary Data
Authors: Pojmański G. 
Published: July 2016

AbstractASAS-3 is the next step in the All Sky Automated Survey. This paper describes the new hardware, consisting of two wide field (9 × 9 deg) telephoto instruments and one F = 750 mm D = 250 mm telescope with 2 × 2 deg FOV, each equipped with a 2K × 2K CCD camera. Wide field instruments are now observing the whole southern sky (almost 30,000 sq. deg) at the average rate of 0.5 measurements per day. A narrow field instrument is connected to the GCN network and is ready to respond to the GRB alerts in tens of seconds. Preliminary photometric data are presented here and briefly discussed.
A Robotic Wide-Angle Hα Survey of the Southern Sky
Authors: Gaustad John E. , Rosing Wayne , McCullough Peter , Van Buren Dave 
Published: July 2016

AbstractWe are conducting a robotic wide-angle imaging survey of the southern sky at 656.3 nm wavelength, the Hα emission line of hydrogen. Each image of the survey covers an area of the sky 13° square at an angular resolution of approximately one arcminute, and reaches a sensitivity level of 0.5 Rayleigh (3 × 10−18erg cm−2s−1arcsec−2), corresponding to an emission measure of 1 cm−6pc, and to a brightness temperature for microwave free-free emission of 3 µK at 30 GHz.
Long-period Red Variables in the Large Magellanic Cloud from the MOA Database
Authors: Takeuti Mine , Noda S. , Abe F. , Bond I. A. , Dodd R. J. , Hearnshaw J. B. , Honda M. , Jugaku J. , Kabe S. , Kilmartin P. M. , Matsubara Y. , Masuda K. , Muraki Y. , Nakamura T. , Nankivell G. R. , Noguchi C. , Ohnishi K. , Rattenbury N. J. , Reid M. , Saito To. , Sato H. , Sekiguchi M. , Skuljan J. , Sullivan D.J. , Sumi T. , Watase Y. , Yanagisawa T. , Yock P. C. M. , Yoshizawa M. 
Published: July 2016

AbstractWe studied 147 long-period red variable stars in the Large Magellanic Cloud from the MOA database. Amongst them, seven red luminous stars are likely pulsating in a higher mode.
The Carl Sagan Observatory: A Telescope for Everyone
Authors: Saucedo-Morales J. , Sánchez-Ibarra A. , Lunt D. 
Published: July 2016

AbstractThe Carl Sagan Observatory is a new project for a remote observatory that will be built at the summit of Cerro Azul (a 2480 m mountain located near Magdalena. Sonora, México). It will include one 55 cm and four 14 cm telescopes. The 55 cm telescope will be dedicated to supernovae research. One of the 14 cm Maksutov telescopes will be used as an autoguider for the stellar observations. The other 14 cm telescopes will feature different narrow band filters that will be used for solar research. The observatory will be controlled from the campus of the Universidad de Sonora in Hermosillo, Sonora, México (~ 200 km from the site). A prototype of the observatory building has been built on campus and first light is expected by the end of May of 2001. We expect to have an operating mountain observatory by the end of 2002. Some of the unique technical aspects of this observatory, which we believe can be a model for future small telescope observatories are discussed in this work.
The NCU Lu-Lin Observatory
Authors: Tsay Wean-Shun , Chen Alfred Bing-Chih , Chang Kuang-Hsiang , Li Huan-Hsin 
Published: July 2016

AbstractThe NCU (National Central University) Lu-Lin observatory is located at Mt. Front Lu-Lin, 120°52′25”E and 23°28′07” N, a 2862-m peak in the Yu-Shan National Park. The construction of Lu-Lin observatory was finished on January 14, 1999. The initial assessment of Lu-Lin site started in 1989, after which a three-year project was founded by the National Science Council (NSC) to support a modern seeing monitoring program. The average seeing at Lu-Lin is about 1.39 arc-second with an average of 200 clear nights annually. The sky background is 20.72 mag/arcsec2 in V band and 21.22 mag/arcsec2 in B band.The Lu-Lin observatory is for both research and education. A homemade 76-cm Super Light Telescope (SLT) and four TAOS 50-cm robotic telescopes for a survey on Kuiper Belt Objects will be the two major research facilities. The pilot program for SLT consists of observations of time-varying astrophysical phenomena. The TAOS #1 telescope was installed at Lu-Lin in March 2000. A 90 KW/240 VAC power line and a water pipe system have been pulled to the site in early 2001. A wireless Network system through A-Li Shan has been operating at Lu-Lin observatory while a faster wireless Network system with 11.5 Mbit/sec bandwidth is under consideration and may be available in the near future for remote observing.
Advantages and Drawbacks of the ISM Method in Globular Cluster Photometry
Authors: Benkő József M. 
Published: July 2016

AbstractIn the framework of our survey of variable stars in galactic globular clusters, we tested the promising new photometric technique, the Image Subtraction Method (Alard & Lupton 1998, Alard 2000). We found that the standard deviations of light curves are much better compared to those of the more common PSF methods (e.g. DAOPHOT), especially in the most crowded regions. Moreover, many additional variable stars have become measurable with this method. Unlike previously published data we have transformed our results into conventional magnitudes. The accuracies of the derived magnitudes are discussed.
The Kinematics of Globular Cluster NGC 288
Authors: Chang Chan-Kao , Chen Alfred B. , Tsay Wean-Shun , Chen Wen-Ping , Lu Phillip K. 
Published: July 2016

AbstractThe mean radial velocity of NGC 288 (accuracy 5.5 km/s) is determined to be −56.3 ± 20.1 km/s which, when combined with the mean proper motion (Guo, 1995), yields a peculiar velocity with respect to the LSR of (u,v,w) = (29.7 ± 18.1, −258.6 ± 18.3,62.3 ± 20.3) km/s. This implies that NGC 288 moves in a retrograde sense with the Galactic rotation. We also derived the effective temperatures for stars in our sample and, as a corroborative effort, compared with those estimated previously from the BATC data (Tsai 1998) by spectral energy distribution fitting. We demonstrate that the BATC/SED fitting is an appropriate and efficient way to estimate the effective temperature of a star.
Former Soviet Union / West Europe Consortium for AGN Monitoring
Authors: Bochkarev N.G. , Shapovalova A.I. , Burenkov A.N. 
Published: July 2016

In the same year as Blandford and McKee (1982), Prof. N. Bochkarev and Dr. I. Antokhin (Bochkarev and Antokhin, 1982) published an article on the reverberation method of AGN BLR structure analysis. In 1983, testing observations were carried out with the 6 m telescope.From 1986 up to now spectral monitoring of several AGNs has been carried out at SAO RAS (North Caucasus). Since 1988 we have been participating in AGN Watch Program. Since 1997 we have been carrying on an international program that is realised at several observatories of CIS (former Soviet Union) in collaboration with several West-European scientific groups (Bochkarev and Shapovalova, 1999). Some spectra of 3C390.3, one of the dimmest target objects of our program, m = 15.6 mag, taken with different telescopes are presented in Fig. 1(left).
The Transfer of Large-scale Magnetic Field by Radial Inhomogeneity of the Material Density in the Rotating Convection Zone
Authors: Krivodubskij V.N. , Kichatinov L.L. 
Published: July 2016

AbstractThe influence of rotation on the transfer of the mean magnetic field of the Sun, caused by the radial inhomogeneity of the solar turbulent plasma density, is investigated. It turns out that the transfer directions of the poloidal and toroidal magnetic fields do not coincide.
Solar Internal Rotation, the Boundary Layer Dynamo and Latitude Distribution of Activity Belts
Authors: Belvedere G. , Proctor M.R.E. , Lanzafame G. 
Published: July 2016

Abstract We suggest that the latitude distribution of solar activity belts and the related equatorward or poleward migration of different tracers of the solar cycle are a natural consequence of the internal radial profile of angular velocity via the working of a dynamo in the boundary layer beneath the convection zone. This has been confirmed by the results of a non-linear dynamo model in a very thin spherical shell which show that dynamo action may reasonably take place in the boundary layer and reproduce the observed surface phenomenology.Extending the argument to late main-sequence stars, it is reasonable to think that observations of the latitude distribution and migration of stellar active regions by current sophisticated techniques may make it possible to infer their internal rotation profile in a simple and direct way.
The Variations of the Hα line of HD199178
Authors: Jetsu Lauri , Savanov Igor , Tuominen Ilkka 
Published: July 2016

AbstractChanges of emission cause variations of the Hα absorption line of HD 199178. The correlation with the simultaneous light curve may depend on the relative strength of the axisymmetric and non-axisymmetric components of the evolving spot configurations.
Full Phase Coverage of BY Dra with the VLA
Authors: Caillault Jean-Pierre , Drake Stephen 
Published: July 2016

AbstractWe have obtained 21 ~one-hour observations of the prototypical spotted star, BY Dra, with the VLA. These data are sufficiently well spaced in time to allow for complete rotational and orbital phase coverage; the resultant radio light curves are compared to their optical counterpart. We also plot the emission versus time without phase-folding, in order to search for longer periods of activity. Splitting the data into smaller (three minute) time bins allows for the determination of the normalized amplitude distribution of the flux; we compare this with known stellar optical and X-ray flare distributions.
Spectral Line Variations in Ap Stars
Authors: Wood H. John 
Published: July 2016

It is the purpose of this review to outline the historical and present uses of time-dependent line-strength studies of Ap stars. One cannot ignore other important types of time-dependent observations such as photoelectric photometry in intermediate and broad bands, or radial velocity curves for selected lines in an Ap star. However, we will attempt to show how line variation studies can provide unique and sometimes crucial tests of theories and models.It would be impossible in this brief paper to mention all the relevant papers we have found during this survey of the literature. Indeed, it is remarkable that this field has been so active over the past 70 years and yet it remains so controversal.
Photoelectric Magnetic Field Measurements of Ap and Bp Stars
Authors: Landstreet J.D. , Borra Ermanno F. 
Published: July 2016

SummaryMagnetic field measurements of numerous Ap and Bp stars have been obtained using a photoelectric technique similar to that employed in the solar magnetograph, applied to Balmer line wings. The accuracy of field measurements obtained is almost independent of projected rotation velocity. A survey of rapidly rotating (v. sin i ≥ 30 km/sec) Ap stars shows that fields of more than 1 kgauss are significantly less common among rapidly rotating Ap stars than among slowly rotating ones. Magnetic fields have been found in two rapidly rotating Ap stars, four southern Ap stars, and the helium-weak star 3 Sco. Magnetic curves obtained for the known magnetic stars 53 Cam and α2CVn show significant differences from the curves observed photographically, in ways which can alter conclusions drawn about the field distributions over the surface of these stars.
Differential Curve-of-Growth Analyses of Mn-Hg Stars
Authors: Kodaira Keiichi 
Published: July 2016

SummarySpectra of eleven Mn-Hg stars (α And,μ Lep, 129 Tau, 14 Hya,κCnc, 30 UMa, πBoo, ι CrB, ϕ Her, ν Her, 46 Dra) are analyzed by the curve-of-growth method. The effective temperature and the surface gravity are estimated from the |u-b|- and the β-indexes and fall into ranges O.346 ≤ θe≤0.451 and 3.4≤log g≤3.8. The microturbulence velocity is found to be in a narrow range of 2 ≲ vt≲ 4.5 km/sec. The resulting chemical composition is very similar among the eleven Mn-Hg stars and shows following characteristics:1)The abundance ratios N(C):N(Si):N(Ca):N(Fe), N(Ti):N(Cr) and N(Sr):N(Y):N(Zr) are nearly identical to those of the sun.2)The enrichment factors relative to Fe are about 10 for Ti and Cr, about 100 for P, Sc, Mn, Sr, Y, and Zr, about 105for Ga, and about 103~106(varying among stars) for Hg.
Photometric Observations of the Metallic Line Stars Around 3600 Å
Authors: Gerbaldi M. , Morguleff N. 
Published: July 2016

SummaryAnalysis of the metallic line stars in the narrow band photometric system Barbier-Morguleff shows an important blocking effect around 3600 Å.For 14 metallic line stars Celescope observations suggest around 2300 Å a blocking effect not so strong as in U filter.
New Celestial Reference System
Authors: Seidelmann P. K. , Kaplan G. H. , Van Flandern T. C. 
Published: July 2016

AbstractThe IAU (1976) System of Astronomical Constants, the FK5 and new lunar and planetary theories are being introduced in 1984. The investigation and planning for the transition has revealed the complex interdependencies between observational techniques and the reference systems, and their strong link to the rotating and orbiting Earth. The inaccuracies in our knowledge of the star positions, astronomical constants and the rotation and motion of the Earth are embedded in subtle ways in the observations and the reference coordinate systems. For example, the FK4 reference system in 1950.0 coordinates rotates with respect to an inertial system. Details are given for the conversion to the new system.
Herschel’s Scientific Apprenticeship and the Discovery of Uranus
Authors: Bennett J.A. 
Published: July 2016

In 1784 Jean-Dominique Cassini, who as Director of the Paris Observatory was one of the foremost professional astronomers of his day, wrote
‘A discovery so unexpected could only have singular circumstances, for it was not due to an astronomer and the marvellous telescope….was not the work of an optician; it was Mr Herschel, an English musician, to whom we owe the knowledge of this seventh principal planet (Schaffer, 1981, 21).
The Stellar Data Center
Authors: Jaschek C. 
Published: July 2016

AbstractThe paper presents an overview of the problems astronomical data centers are facing today.When one organizes a colloquium, one can do some fairly outrageous things, like putting ones own contribution first . However as an excuse for such a procedure, I shall say that I want really not to discuss that much what the C.D.S. itself does, but what problems we have been confronted with, specially those which came up since the last Strasbourg colloquium, or which got more complicated to handle.
Management of Astronomical Data at Kanazawa Data Center
Authors: Terashita Yoichi 
Published: July 2016

AbstractThe methods of controlling and disseminating astronomical data at the Kanazawa Data Center (operated under the Computer Center of the Kanazawa Institute of Technology) are described. Discussions include the coded data descriptions used in conjunction with a file processing language. Problems concerning remote data access are also discussed, and the future plan presented.
Infrared Astronomical Data Base and Catalog of Infrared Observations
Authors: Schmitz Marion , Gezari Daniel Y. , Mead Jaylee M. 
Published: July 2016

AbstractA computer data base of infrared astronomical observations has been established at NASA/Goddard Space Flight Center. It contains a summary of all infrared (1µm-1000µm) observations of celestial sources outside the solar system, published in the major scientific journals since 1960, as well as the contents of infrared surveys and catalogs. A Catalog of Infrared Observations (CIO) has been developed from the data base in printed and magnetic tape versions. A bibliographic Guide to the Infrared Astronomical Literature, and an Atlas of Infrared Source Names and Positions will be published in conjunction with the catalog. Future plans include development of an interactive data system at Goddard which will give a user direct access to the computerized data.
Responsibilities and practical limitations in the operation of an astronomical data center
Authors: Warren Wayne H. , Mead Jaylee M. , Nagy Theresa A. 
Published: July 2016

AbstractThe operation of an astronomical data center requires that many decisions be made concerning the handling of the astronomical catalogs and data distributed. Should a data center be, as Wilkins (1977) described it, passive, in that catalogs and data are collected and distributed blackbox-wise upon request, or should a data center be active and have experts in various fields to scrutinize, correct, reformat, and document data where necessary? These questions will be addressed and illustrated by describing the current operations and future goals of the Astronomical Data Center at NASA/GSFC.
Proton Induced X-Ray Emission (Pixe) Analysis of Meteoritic Microsamples
Authors: Wallenwein R. , Blank H. , Jessberger E.K. , Traxel K. 
Published: July 2016

AbstractInterplanetary dust particles (IDPs) collected in the stratosphere are thought to be mostly of cometary origin. They survived heating during their deceleration in the earth’s atmosphere (1). Because of their small size (< 50 μm ) and mass (< 10−7 g) they are difficult to analyse. Special preparation and examination methods have been developed for their investigations (2). We set out to study the trace-element-composition of these particles using the Heidelberg proton microprobe.
Laboratory Infrared Transmission Measurements of Interplanetary Dust and Implications for Remote Observations of Cosmic Particles
Authors: Sandford S.A. , Walker R.M. 
Published: July 2016

AbstractLaboratory infrared absorption spectra of interplanetary dust particles show that most fall into one of three spectral groups (1) designated as “pyroxenes”, “olivines”, and “hydrated silicates”.Comparisons with 10 μm emission data from Comet Kohoutek (2) show that no single spectral type matches the cometary data. However, a reasonable match is obtained by coadding equal amounts of pyroxene and hydrated silicate type spectra.The possibility that the 10 μm feature seen in some comets is due to a combination of these two components can be tested in two ways. First, the pyroxene type spectra show detailed features of variable position and strength within their 10 μm bands. Based on the laboratory data we estimate that comet spectra taken at a resolution of λ/Δλ ~ 200 would be sufficient to find these features, if present. The magnitude of these features is expected to be ≤ 0.1 of the maximum strength of the 10 μm band.Second, the hydrated silicate particles usually have bands at 3.0, 6.2, and 6.9 µm. The first two bands are probably linked to the presence of water while the 6.9 μm band is probably due to carbonates. The 3.0 μm feature is broad and might be hard to separate from thermal background. However, spectra taken at resolutions of λ/Δλ ~ 50 could see the 6.2 and 6.9 μm bands. The strengths of these bands (which are also seen in the spectra of CM meteorites) vary (one particle has a carbonate band that is actually stronger than its corresponding 10 μm silicate band), but are typically ~0.1 the depth of the silicate features. A second, narrow carbonate band at 11.4 μm can also sometimes be seen in particle spectra but its strength is less than that of the 6.9 μm band. This the search for the 6.2 and 6.9 μm bands in astronomical objects, while not requiring high resolutions, would require good S/N.
Planetary Perturbations: Effects on the Shape of a Cloud of Dust in Circular Heliocentric Orbits
Authors: Gustafson Bo Å. S. 
Published: July 2016

AbstractSynthetic infrared pictures are used to illustrate changes in the shape of portions of an interplanetary dust-cloud. The dust particles, in circular heliocentric orbits, are perturbed by radiation and corpuscular forces combined with gravitational disturbances by the major planets. Dust in the inner solar system and close to the ecliptic or the orbital plane of Venus is brought to a more narrow range of ecliptic latitudes. A dust-band evolves near and inside the orbit of Venus. The cloud’s shape is less affected at high ecliptic latitudes.
A Comparison of Various NLTE Codes in Computing the Charge-State Populations of an Argon Plasma
Authors: Stone Sam R. , Weisheit Jon C. 
Published: July 2016

A comparison among nine computer codes shows surprisingly large differences where it had been believed that the computational physics was well understood. The codes simulate a plasma that is in steady state but not in local thermodynamic equilibrium (NLTE codes). In this study each code treats an “easy” problem, which is an argon plasma, optically thin and with no external photon flux; densities are varied from near-coronal to an intermediate 1021 electrons/cc and above. The temperatures are high enough that most ions have two or fewer bound electrons, which for this plasma means temperatures above about 300 eV.The present study asks only if the codes compute similar charge-state populations (a surprising “no”), and, if not, why not. It does not claim accuracy for any code either by comparison to experiment or by appeal to a concensus.