Typescript
Topics: Spiral galaxies, Spiral galaxies
Click here to view the University of Florida catalog record
Topic: Spiral galaxies
Click here to view the University of Florida catalog record
Topic: Spiral galaxies
Click here to view the University of Florida catalog record
Topic: Spiral galaxies
786
786
Aug 19, 2009
08/09
by
NASA
image
eye 786
favorite 1
comment 0
Taken by the Hubble Space Telescope in 1999, the larger and more massive galaxy is cataloged as NGC 2207 (on the left in the Hubble Heritage image), and the smaller one on the right is IC 2163.
Topics: A Grazing Encounter Between Two Spiral Galaxies, What -- Hubble Space Telescope (HST)
Source: http://www.nasa.gov/50th/favpic/spiralGalaxies.html
361
361
Jul 11, 2010
07/10
by
NON
texts
eye 361
favorite 0
comment 0
The author has identified the following significant results. A color composite of image E1010-14035, dated 2 August 1972, covers the west central Bolivian Altiplano near Salar de Coipasa. It clearly shows the distribution of surface water and scant patches of vegetation. The Salar de Coipasa is the largest body of water in the area, about 130 sq km of dark blue fresh water. A lighter blue area south of the lake suggests a thin cover of highly saline water superposed on salt beds. The scattered...
Topics: COSMIC RAYS, GALACTIC RADIATION, GAMMA RAYS, DISKS (SHAPES), MODELS, SAS-2, SPIRAL GALAXIES
368
368
May 22, 2011
05/11
by
Isar, Aurelia
texts
eye 368
favorite 0
comment 0
The harmonic oscillator with dissipation is studied within the framework of the Lindblad theory for open quantum systems. By using the Wang-Uhlenbeck method, the Fokker-Planck equation, obtained from the master equation for the density operator, is solved for the Wigner distribution function, subject to either the Gaussian type or the delta-function type of initial conditions. The obtained Wigner functions are two-dimensional Gaussians with different widths. Then a closed expression for the...
Topics: BRIGHTNESS, DUST, MASSIVE STARS, RADII, SPIRAL GALAXIES, STAR FORMATION, HEATING, INTERSTELLAR...
246
246
Jul 26, 2010
07/10
by
Bingel, Bradford D
texts
eye 246
favorite 0
comment 0
The Analytic Patch Configuration (APC) is an interactive software tool which translates aircraft configuration geometry files from one format into another. This initial release of the APC Gateway accommodates six formats: the four accepted APC formats (89f, 89fd, 89u, and 89ud), the PATRAN 2.x phase 1 neutral file format, and the Integrated Aerodynamic Analysis System (IAAS) General Geometry (GG) format. Written in ANSI FORTRAN 77 and completely self-contained, the APC Gateway is very portable...
Topics: COSMIC DUST, SILICATES, DISTRIBUTION (PROPERTY), HALOS, SPIRAL GALAXIES, DIELECTRICS, EQUATIONS OF...
369
369
May 24, 2011
05/11
by
Roberts, S. G.; Hutchinson, T. M.; Arnaud, S. B.; Kiratli, B. J; Steele, C. R
texts
eye 369
favorite 0
comment 0
Accurate non-invasive mechanical measurement of long bones is made difficult by the masking effect of surrounding soft tissues. Mechanical response tissue analysis (MRTA) offers a method for separating the effects of the soft tissue and bone; however, a direct validation has been lacking. A theoretical analysis of wave propagation through the compressed tissue revealed a strong mass effect dependent on the relative accelerations of the probe and bone. The previous mathematical model of the bone...
Topics: SPIRAL GALAXIES, CONFERENCES, SEYFERT GALAXIES, INTERSTELLAR MATTER, BLACK HOLES (ASTRONOMY),...
The increase in random kinetic energy of stars by rapidly fluctuating gravitational fields (collisionless or violent relaxation) in disk galaxy models is investigated for three interaction potentials of the stars corresponding to (1) point stars, (2) rod stars of length 2 kpc, and (3) uniform density spherical stars of radius 2 kpc. To stabilize the galaxy against the large scale bar forming instability, a fixed field corresponding to a central core or halo component of stars was added with the...
Topics: NASA Technical Reports Server (NTRS), KINETIC ENERGY, SPIRAL GALAXIES, GRAVITATIONAL FIELDS,...
It is explained why one can observe a leading spiral pattern in close pairs of galaxies where the direction of the orbital momentum of the satellite is opposite to the direction of the spin of the spiral galaxy.
Topics: NASA Technical Reports Server (NTRS), DIRECTION, GALACTIC ROTATION, ORBITS, SPIRAL GALAXIES,...
306
306
Jul 26, 2010
07/10
by
Miles, Richard H.; Schulman, Joel N.; Chow, D. H.; Mcgill, Tom C
texts
eye 306
favorite 0
comment 0
The successful growth of InAs/Ga(1-x)In(x)Sb superlattices and their optical and structural characterization is discussed. Samples were grown by molecular beam epitaxy at fairly low substrate temperatures (less than 400 C). Structural quality was assessed by reflection high energy electron difrraction, transmission electron microscopy, and x ray diffraction. Excellent structures were achieved for growth on thick, strain relaxed GaSb buffer layers on GaAs substrates, despite a residual threading...
Topics: CARBON MONOXIDE, TELESCOPES, DETECTION, EMISSION, GALACTIC CLUSTERS, SPIRAL GALAXIES, VIRGO...
200
200
May 6, 2010
05/10
by
Burbidge, E. M
texts
eye 200
favorite 0
comment 0
Ultraviolet radiation emission from normal elliptical, spiral, and irregular galaxies
Topics: ELLIPTICAL GALAXIES, ULTRAVIOLET RADIATION, ELLIPTICITY, EMISSION, GALACTIC RADIATION, IRREGULAR...
503
503
May 28, 2011
05/11
by
Jaunky, N.; Ambur, D. R.; Knight, N. F., Jr
texts
eye 503
favorite 0
comment 0
A design strategy for optimal design of composite grid-stiffened cylinders subjected to global and local buckling constraints and strength constraints was developed using a discrete optimizer based on a genetic algorithm. An improved smeared stiffener theory was used for the global analysis. Local buckling of skin segments were assessed using a Rayleigh-Ritz method that accounts for material anisotropy. The local buckling of stiffener segments were also assessed. Constraints on the axial...
Topics: X RAY SOURCES, EMISSION, SPIRAL GALAXIES, POINT SOURCES, OBSERVATION, X RAY ASTROPHYSICS FACILITY,...
290
290
Aug 2, 2010
08/10
by
Barth, Timothy J.; Wiltberger, N. Lyn; Gandhi, Amar S
texts
eye 290
favorite 0
comment 0
Algorithms for the generation of 3D unstructured surface and volume grids are discussed. These algorithms are based on incremental insertion and local optimization. The present algorithms are very general and permit local grid optimization based on various measures of grid quality. This is very important; unlike the 2D Delaunay triangulation, the 3D Delaunay triangulation appears not to have a lexicographic characterization of angularity. (The Delaunay triangulation is known to minimize that...
Topics: INFRARED ASTRONOMY, INFRARED SOURCES (ASTRONOMY), RADIO ASTRONOMY, RADIO GALAXIES, SPIRAL GALAXIES,...
A variety of observations of galaxies in clusters indicate that the gas in these galaxies is strongly affected by the cluster environment. We present results of a study of the dynamical effects of the mean cluster tidal field on a disk galaxy as it falls into a cluster for the first time on a bound orbit with constant angular momentum (Valluri 1992). The problem is studied in the restricted 3-body framework. The cluster is modelled by a modified Hubble potential and the disk galaxy is modelled...
Topics: NASA Technical Reports Server (NTRS), DISK GALAXIES, GALACTIC CLUSTERS, GALACTIC EVOLUTION, SPIRAL...
303
303
Jul 26, 2010
07/10
by
Bougen, H.; Wright, James P
texts
eye 303
favorite 0
comment 0
No Abstract Available
Topics: DENSITY WAVE MODEL, GRAVITATIONAL FIELDS, MILKY WAY GALAXY, PHOTOMETRY, SPIRAL GALAXIES, STELLAR...
1,058
1.1K
Jun 1, 2011
06/11
by
Baldridge, Jennifer; Villegas, Yvonn
texts
eye 1,058
favorite 0
comment 0
Several preliminary materials compatibility studies have been conducted to determine the practicality of a new hypergolic fuel system. Hypergolic fuel ignites spontaneously as the oxidizer decomposes and releases energy in the presence of the fuel. The bipropellant system tested consists of high-test hydrogen peroxide (HTP) and a liquid fuel blend consisting of a hydrocarbon fuel, an ignition enhancer and a transition metal catalyst. In order for further testing of the new fuel blend to take...
Topics: ACCRETION DISKS, X RAY SOURCES, HIGH TEMPERATURE, BLACK HOLES (ASTRONOMY), SPIRAL GALAXIES, STELLAR...
Under the grant we studied the X-ray emission from galaxies, clusters, and gravitational lenses as observed by ROSAT. In addition to several invited and contributed talks presented at conferences, the following papers (listed with their abstracts) that are published in refereed journals were completed as part of this activity.
Topics: NASA Technical Reports Server (NTRS), GALACTIC RADIATION, SPIRAL GALAXIES, X RAYS, GALACTIC...
Several oscillations have been identified in spherical galaxy models. These are normal mode oscillations in a stable galaxy. Each has its own distinct period and spatial form, and each rings without detectable damping through a Hubble time. The most important are: (1) a simple radial pulsation (fundamental mode), in which all parts of the galaxy move inward or outward with the same phase; and (2) a second spherically symmetrical radial mode with one node, so material inside the node moves...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, GALAXIES, OSCILLATIONS, STAR FORMATION,...
The purpose of the grant was to obtain and analyze International Ultraviolet Explorer (IUE) spectra of the spiral galaxy NGC 4395, which contains the nearest and least luminous known Seyfert nucleus. The ultraviolet (UV) spectra was to be used to test the intriguing hypothesis that the 'activity' could be explained by purely stellar phenomena, and to further explore the unprecedented properties of this nucleus. To test the feasibility of the project (the nucleus of NGC 4395 is very faint), one...
Topics: NASA Technical Reports Server (NTRS), SEYFERT GALAXIES, SPIRAL GALAXIES, STELLAR ACTIVITY,...
We present results of three-dimensional, hydrodynamic models of gaseous disks settling in a nonspherical potential. As the gas settles, differential precession creates a warped disk similar to the warps seen in spiral galaxies. A logarithmic potential, indicative of a massive halo, seems to induce warps more extreme than those produced by a l/r potential with a quadrupole distortion.
Topics: NASA Technical Reports Server (NTRS), ANGULAR MOMENTUM, MOMENTUM TRANSFER, PRECESSION, SPIRAL...
The distribution of morphological types of galaxies in compact groups is studied on plates from the 6 m telescope. In compact groups there are 57 percent galaxies of late morphological types (S + Irr), 23 percent lenticulars (SO) and 20 percent elliptical galaxies. The morphological content of compact groups is very nearly the same as in loose groups. There is no dependence of galaxy morphology on density in all compact groups (and possibly in loose groups). Genuine compact groups form only 60...
Topics: NASA Technical Reports Server (NTRS), ELLIPTICAL GALAXIES, GALACTIC CLUSTERS, SPATIAL DISTRIBUTION,...
The galaxy merging is investigated with hydrodynamical processes taken into account. For this purpose, the 3D calculations are performed by the use of a smoothed particle hydrodynamics (SPH) scheme combined with an N-body scheme. In these calculations, we find a new merging criterion and the dependence of the central phase space density of merger remnants upon the gas fraction in progenitors. It is concluded that ellipticals can be formed just by merging of fairly gas-rich primordial galaxies,...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, ELLIPTICAL GALAXIES, GALACTIC EVOLUTION,...
A portion of the observing time with the Hubble Space Telescope (HST) was awarded by NASA to scientists involved in the development of the HST and its instruments. These scientists are the Guaranteed Time Observers (GTO's). Observing time was also awarded to General Observers (GO's) on the basis of the proposal reviews in 1989 and 1991. The majority of the 1989 programs have been completed during 'Cycle 1', while the 1991 programs will be completed during 'Cycle 2', nominally a 12-month period...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL CATALOGS, ASTRONOMICAL PHOTOMETRY, HUBBLE SPACE...
Multiobject spectroscopy results of HII regions in nearby late-type spiral galaxies are given. Results include excitation measurements, log ((O III)/H beta), for 81 regions in M 101, 30 regions in NGC 2403, and 13 regions in M 51. Researchers conclude that late-type spirals can be classified into two distinct populations, examine possible causes of this division, and derive metallicity gradients for these galaxies. M 51 appears to have an anomalously shallow abundance gradient.
Topics: NASA Technical Reports Server (NTRS), H II REGIONS, SPECTROSCOPY, SPIRAL GALAXIES, EXCITATION,...
The grant contributed to the publication of 18 refereed papers and 5 conference proceedings. The primary uses of the funding have been for page charges, travel for invited talks related to the grant research, and the support of a graduate student, Charles Keeton. The refereed papers address four of the primary goals of the proposal: (1) the statistics of radio lenses as a probe of the cosmological model (#1), (2) the role of spiral galaxies as lenses (#3), (3) the effects of dust on statistics...
Topics: NASA Technical Reports Server (NTRS), COSMOLOGY, ASTRONOMICAL MODELS, SPIRAL GALAXIES, GALACTIC...
A reexamination of Dressler's (1980) sample of nearly 6000 galaxies in 55 clusters shows that the morphology-clustercentric radius relation is more fundamental than the morphology-local density relation. This conclusion is supported by improved correlations when the projected clustercentric radius is used as the independent parameter, and by a comparison of galaxies with the same normalized clustercentric radii by different values of the projected local density.
Topics: NASA Technical Reports Server (NTRS), ELLIPTICAL GALAXIES, GALACTIC CLUSTERS, GALACTIC EVOLUTION,...
226
226
May 23, 2011
05/11
by
Li, Hongwei; McCray, Richar
texts
eye 226
favorite 0
comment 0
By the time the expanding envelope of a Type 2 supernova becomes transparent in the optical continuum, most of the gamma-ray luminosity produced by radioactive Fe/Co/Ni clumps propagates into the hydrogen/helium envelope and is deposited there, if at all. The resulting fast electrons excite He 1 and H 1, the two- photon continua of which are the dominant internal sources of ultraviolet radiation. The UV radiation is blocked by scattering in thousands of resonance lines of metals and converted...
Topics: LYMAN ALPHA RADIATION, HYDROGEN, ABSORPTION SPECTRA, DWARF GALAXIES, SPIRAL GALAXIES, RADIO...
The original Revised Shapley-Ames (RSA) galaxy sample of almost 1300 galaxies has been augmented with further bright galaxies from the RSA appendix as well as newer galaxy catalogs. A complete and homogeneous, strictly magnitude-limited all-sky sample of 2345 galaxies brighter than 13.4 in apparent blue magnitude was formed. New 21 cm H1 line observations for more than 600 RSA galaxies have been combined with all previously available H1 data from the literature. This new extentise data act...
Topics: NASA Technical Reports Server (NTRS), DATA REDUCTION, EMISSION SPECTRA, LINE SPECTRA, MICROWAVE...
Kennicutt and Kent (1983) have shown that the global H alpha emission from a spiral galaxy is an indicator of the formation rate of massive stars. Moss, Whittle and Irwin (1988) have surveyed two clusters (Abell 347 and 1367) for galaxies with H alpha emission using a high dispersion objective prism technique. The purpose of the survey is to investigate environmental effects on star formation in spiral galaxies, and in particular to ascertain whether star formation is enhanced in cluster...
Topics: NASA Technical Reports Server (NTRS), EMISSION, GALACTIC CLUSTERS, INTERACTING GALAXIES, SPIRAL...
A declining rotation curve was recently found for the galaxy NGC 3521 by HI synthesis telescope observations (Casertano and van Gorkom 1991). From a comparison of the shapes of rotation curves for a larger sample of galaxies Casertano and van Gorkom argue that this is due to initial properties during the phase of galaxy formation. In several studies of global properties of galaxies, NGC 3521 was always considered a 'normal' unbarred, non-interacting, isolated spiral. However, we present CCD...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL PHOTOMETRY, GALACTIC EVOLUTION, INTERACTING...
We use high resolution (HiRes) 60 and 100 micron data to investigate the variation of the dust temperature in a sample of 4 late-type spiral galaxies. We have investigated the radial variation of the azimuthally averaged 60 and 100 micron surface brightness profiles to see how the dust temperature (or, more correctly, the relative strength of the two components) varies as a function of radius within the galaxies. We find strong evidence for a decrease in the dust temperature (or an increase in...
Topics: NASA Technical Reports Server (NTRS), BRIGHTNESS, DUST, MASSIVE STARS, RADII, SPIRAL GALAXIES, STAR...
It has long been held that the star formation rate (SFR) may be described as a power law of the gas density, p(exp n), as given by Schmidt (1959). However, this relation has as yet remained poorly defined and is likewise poorly understood. In particular, most studies have been investigations of global gas and star formation properties of galaxies, due to lack of adequate high-resolution data for detailed studies of individual galaxies. The three spiral galaxies in this study have published maps...
Topics: NASA Technical Reports Server (NTRS), GALAXIES, GAS DENSITY, GRAVITATION, SPIRAL GALAXIES, STAR...
Tidal interaction between the galaxies in binary systems leads to important consequences. Some peculiarities in galactic morphology as well as the transfer of matter from one galaxy to another may be due to this factor. In particular, gas flows in intergalactic space may be formed. Such flows enriching one component with gas from the other may play a substantial role in the evolution of mixed (S-E) pairs. One can mention several facts corroborating the possibility of the gas transfer from the...
Topics: NASA Technical Reports Server (NTRS), ELLIPTICAL GALAXIES, EMISSION SPECTRA, GAS FLOW, KINEMATICS,...
The evolution of an initially balanced rotating disk of stars with an initial velocity dispersion given by Toomre's local criterion was investigated by means of a computer model for isolated disks of stars. It was found that the disk is unstable against very large scale modes. A stable axisymmetric disk with a velocity dispersion much larger than that given by Toomre's criterion was generated. The final mass distribution for the disk gives a high density central core and a disk population of...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, DISKS (SHAPES), GALACTIC EVOLUTION,...
230
230
May 31, 2011
05/11
by
Heber, Gerd; Biswas, Rupak; Gao, Guang R
texts
eye 230
favorite 0
comment 0
Space-filling curves is a popular approach based on a geometric embedding for linearizing computational meshes. We present a new O(n log n) combinatorial algorithm for constructing a self avoiding walk through a two dimensional mesh containing n triangles. We show that for hierarchical adaptive meshes, the algorithm can be locally adapted and easily parallelized by taking advantage of the regularity of the refinement rules. The proposed approach should be very useful in the runtime partitioning...
Topics: X RAY BINARIES, OUTGASSING, X RAY ASTRONOMY, X RAY SPECTROSCOPY, STELLAR LUMINOSITY, SPIRAL...
336
336
May 23, 2011
05/11
by
Tam, Christopher K. W.; Fang, Jun; Kurbatskii, Konstantin A
texts
eye 336
favorite 0
comment 0
A set of nonhomogeneous radiation and outflow conditions which automatically generate prescribed incoming acoustic or vorticity waves and, at the same time, are transparent to outgoing sound waves produced internally in a finite computation domain is proposed. This type of boundary condition is needed for the numerical solution of many exterior aeroacoustics problems. In computational aeroacoustics, the computation scheme must be as nondispersive ans nondissipative as possible. It must also...
Topics: INFRARED SPECTRA, METHYLENE, POLYCYCLIC AROMATIC HYDROCARBONS, INFRARED RADIATION, SHOCK HEATING,...
Any spiral structure in computer-generated galaxies is generally short lived and the final state is a rotating bar. The bar thus obtained rotates more slowly than the stars. It has been argued that core/halo components have a stabilizing effect on galaxies and result in longer lived spiral structure. However, numerical experiments with large fixed stellar components representing the core/halo component show that multiarmed spiral structure develops and persists for many rotations but only in an...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, MANY BODY PROBLEM, PLASMAS...
From a study of spiral galaxies in the Virgo Cluster (VC), it is shown that the RDDO anemics with smooth arms and no sign of present formation of (massive) stars have HI surface densities below a threshold value of 2 to 5 x 10 to the 20th power atoms/sq cm. This value is very consistent with predictions of theoretical models. It is likely that the HI disks of VC HI-deficient RDDO anemics were deeply affected by ram pressure stripping in the gaseous intracluster medium, while VC HI deficient...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, GALACTIC EVOLUTION, SPIRAL GALAXIES,...
The ways in which recent infrared observations, particularly by the Infrared Astronomy Satellite (IRAS), have influenced ideas about star formation in normal galaxies, are discussed.
Topics: NASA Technical Reports Server (NTRS), GALACTIC STRUCTURE, LUMINOSITY, RADIO ASTRONOMY, SPIRAL...
Progress towards understanding the nature of the COS-B galactic gamma-ray sources was made by two recent developments. The developments are: (1) the existence of extensive wide-latitude CO surveys, from the Northern Hemisphere, and from the Southern Hemisphere which give more precise information on molecular cloud population of the Perseus, Sagittarius, and Carina spiral arms; (2) the study of the time variability of gamma-ray sources in gamma-rays but also at other wavelengths, leading to the...
Topics: NASA Technical Reports Server (NTRS), GALACTIC RADIATION, MOLECULAR CLOUDS, RADIATION SOURCES,...
At the end of three days' spirited discussion of the type 2 Seyfert galaxy NGC 1068, what do we think we understand about this object? New observations, particularly in the infrared and radio are helping to resolve old problems, while drawing attention to new ones. It appears that NGC 1068 is a relatively normal spiral galaxy in which large-scale gravitational disturbances are funneling matter into the nucleus. A collimated outflow disturbs the interstellar medium out to kiloparsec scales, but...
Topics: NASA Technical Reports Server (NTRS), SPIRAL GALAXIES, CONFERENCES, SEYFERT GALAXIES, INTERSTELLAR...
The program's goal was to understand the physics underlying the [O III] (lambda)5007 planetary nebula luminosity function (PNLF) and evaluate its accuracy as an extragalactic distance indicator. Work under the grant concentrated in two areas. The first major goal was to extensively test the PNLF method to find its limits. We did this performing yet another internal test of the method in the core galaxies of the Fornax Cluster, performing external comparisons of PNLF distances with distances...
Topics: NASA Technical Reports Server (NTRS), RESEARCH, PLANETARY NEBULAE, LUMINOSITY, H II REGIONS,...
A survey of bright Hydra cluster spiral galaxies for the CO(1-0) transition at 115 GHz was performed with the 15m Swedish-ESO submillimeter telescope (SEST). Five out of 15 galaxies observed have been detected in the CO(1-0) line. The largest spiral galaxy in the cluster, NGC 3312, got more CO than any spiral of the Virgo cluster. This Sa-type galaxy is optically largely distorted and disrupted on one side. It is a good candidate for ram pressure stripping while passing through the cluster's...
Topics: NASA Technical Reports Server (NTRS), CARBON MONOXIDE, DETECTION, EMISSION, GALACTIC CLUSTERS,...
NGC 3077 is the third largest system in the M81 swarm of galaxies, after the giant spiral M81 itself and dwarf oddity M82. We are interested in exploring the fate of molecular material in NGC 3077. For that reason we have mapped the distribution of J = 1 to 0 CO emission in the central approximately 1 arcmin (1 kpc) diameter region of the galaxy using the Owens Valley millimeter-array with an angular resolution of 6.'7 x 5.'7 (110 pc x 90 pc). The results are shown on the following page as a...
Topics: NASA Technical Reports Server (NTRS), DWARF GALAXIES, MAPS, MOLECULAR GASES, SPIRAL GALAXIES, STAR...
The stability of two-dimensional interstellar gas flow passing through a spiral potential has been investigated. The background flow is assumed to move in a tightly wound potential, which may be regarded as external or self-generated. The unperturbed flow, which may be time dependent, is self-gravitating and satisfies the Roberts equations of motion. A polytropic, single-fluid assumption has been used. Magnetic effects are not considered. The motivation behind this work is to try to understand...
Topics: NASA Technical Reports Server (NTRS), COMPARISON, DYNAMIC STABILITY, GAS DYNAMICS, INTERSTELLAR...
Early theoretical work of Parker is presented along with the observational evidence supporting his Archimedes spiral model. Variations present in the interplanetary magnetic field from the spiral angle are related to structures in the solar wind. The causes of these structures are found to be either nonuniform radial solar wind flow or the time evolution of the photospheric field. Coronal magnetic models are related to the connection between the solar magnetic field and the interplanetary...
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY MAGNETIC FIELDS, SOLAR CYCLES, SOLAR WIND,...
Work included the analysis of the HRJ observations of the Sombrero galaxy (Fabbiano and Juda) published in Ap.J. This paper discussed the discovery of a point-like x-ray source at the nucleus of the galaxy, which is suspected to host a massive black hole. More work was done on the analysis of the Observation of M94 in support of an AXAF proposal. We have also analyzed the M81 data by adding to our observation the entire set of the archival ROSAT data. We plan to write up the results for...
Topics: NASA Technical Reports Server (NTRS), X RAY SOURCES, EMISSION, SPIRAL GALAXIES, POINT SOURCES,...
Galactic CO line emission at 115 GHz was surveyed in order to study the distribution of molecular clouds in the inner galaxy. Comparison of this survey with similar H1 data reveals a detailed correlation with the most intense 21 cm features. To each of the classical 21 cm H1 spiral arms of the inner galaxy there corresponds a CO molecular arm which is generally more clearly defined and of higher contrast. A simple model is devised for the galactic distribution of molecular clouds. The modeling...
Topics: NASA Technical Reports Server (NTRS), EMISSION SPECTRA, GALACTIC STRUCTURE, MOLECULAR CLOUDS,...
