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May 23, 2011
05/11
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Mitskevich, Amanda M.; Murray, Susan L.; Safford, Robert R.; Swart, William W
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Time standards are usually developed for highly repetitive tasks of short duration. Therefore, most of the work measurement techniques available for producing standards are formulated for this level of activity. There is an increasing need for standards on tasks that are less repetitive and of longer duration. It is also necessary to continue to ensure that the development of the standards is cost effective. One way to assist in minimizing cost is to select the appropriate technique for the...
Topics: ASTROPHYSICS, COSMOLOGY, GINGA SATELLITE, SURVEYS
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May 31, 2011
05/11
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Patt, Frederick S
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The navigation algorithms for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) were designed to meet the requirement of 1-pixel accuracy-a standard deviation (sigma) of 2. The objective has been to extract the best possible accuracy from the spacecraft telemetry and avoid the need for costly manual renavigation or geometric rectification. The requirement is addressed by postprocessing of both the Global Positioning System (GPS) receiver and Attitude Control System (ACS) data in the...
Topics: SEYFERT GALAXIES, IRON, GINGA SATELLITE, CENTROIDS, ACCRETION DISKS, X RAYS, PHOTOIONIZATION, K...
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May 21, 2011
05/11
by
Zhuang, W.; Chouinard, J.-Y.; Yongacoglu, A
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Land mobile satellite communications at Ka-band (30/20 GHz) are attracting an increasing interest among researchers because of the frequency band availability and the possibility of small earth station designs. However, communications at the Ka-band pose significant challenges in the system designs due to severe channel impairments. Because only very limited experimental data for mobile applications at Ka-band is available, this paper studies the channel characteristics based on experimental...
Topics: GALAXIES, TORQUE, VISUAL OBSERVATION, X RAYS, GINGA SATELLITE, MASS TRANSFER, PULSARS, STELLAR...
This grant was awarded to Dr. C. Megan Urry of the Space Telescope Science Institute in response to two successful ADP proposals to use archival Ginga and Rosat X-ray data for 'Testing the Pairs-Reflection model with X-Ray Spectral Variability' (in collaboration with Paola Grandi, now at the University of Rome) and 'X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects' (in collaboration with then-graduate student Rita Sambruna, now a post-doc at Goddard Space Flight...
Topics: NASA Technical Reports Server (NTRS), BL LACERTAE OBJECTS, NASA PROGRAMS, ROSAT MISSION, X RAYS,...
We proposed to search for high-temperature, flare-produced Fe XXIII line emission from active cool star binary systems using the ALEXIS all-sky survey. Previous X-ray transient searches with ARIEL V and HEAO-1, and subsequent shorter duration monitoring with the GINGA and EXOSAT satellites demonstrated that active binaries can produce large (EM approximately equals 10(exp 55-56/cu cm) X-ray flares lasting several hours or longer. Hot plasma from these flares at temperatures of 10(exp 7)K or...
Topics: NASA Technical Reports Server (NTRS), X RAYS, COOL STARS, EXTREME ULTRAVIOLET RADIATION, HIGH...
This grant was to support the reduction and analysis of our approved XMM observation of the nearby Seyfert 2 galaxy NGC 5506. The observation has been carried out simultaneously with a BeppoSAX observation of the same source. The proposal was aimed to study in detail the Compton reflection component and the complex Iron K line of this source, combining the still unique capability of BeppoSAX in hard X-rays (to strongly constrain the reflection component, and then the intrinsic nuclear...
Topics: NASA Technical Reports Server (NTRS), SEYFERT GALAXIES, X RAYS, PHOTOIONIZATION, K LINES,...
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May 24, 2011
05/11
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Wang, Alian; Jolliff, Bradley L.; Haskin, Larry A
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The sharp, nonoverlapping Raman bands for plagioclase, pyroxene, and olivine would be advantageous for on-surface, active mineralogical analysis of lunar materials. A robust, light-weight, low-power, rover-based Raman spectrometer with a laser exciting source, entirely transmission-mode holographic optics, and a charge-coupled device (CCD) detector could fit within a less than 20 cm cube. A sensor head on the end of an optical fiber bundle that carried the laser beam and returned the scattered...
Topics: SEYFERT GALAXIES, MODELS, ABSORBERS, ENERGY BANDS, TEMPORAL DISTRIBUTION, BLACK BODY RADIATION, X...
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May 23, 2011
05/11
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Ng, Daniel; Spuckler, Charles M
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The self calibrating emissivity and/or transmissivity independent multiwavelength pyrometer is ideally suited to measure the temperature of a surface when the emissivity of the surface and the transmissivity of the medium separating the surface from the pyrometer are either or both not known. Such is the case of the tungsten filament in a quartz lamp. Using a one-color pyrometer would require knowing the quartz lamp envelope transmissivity and the filament's emissivity to measure temperature....
Topics: FLARE STARS, IUE, ROSAT MISSION, VERY LARGE ARRAY (VLA), LIGHT CURVE, X RAYS, X RAY ASTRONOMY,...
The key goal of the observation of X0748-67B was to study changes in the time of the X-ray eclipses in order to determine the orbital period, which, in turn allows us to infer properties of the system. We attempted to carry out ROSAT observations but both scheduled pointings missed the requested ephemerides to see the eclipses. We were, however, able to use ASCA performance verification phase data to undertake our intended scientific goal and the combined ASCA/Ginga data were published as:...
Topics: NASA Technical Reports Server (NTRS), X RAY BINARIES, TIME FUNCTIONS, ECLIPSES, ORBITAL SERVICING,...
This program involves analysis and interpretation of results from GINGA Large Area Counter (LAC) observations from a group of large stellar X-ray flares. All LAC data are re-extracted using the standard Hayashida method of LAC background subtraction and analyzed using various models available with the XSPEC spectral fitting program.Temperature-emission measure histories are available for a total of 5 flares observed by GINGA. These will be used to compare physical parameters of these flares...
Topics: NASA Technical Reports Server (NTRS), COUNTERS, DATA ACQUISITION, DATA PROCESSING, GINGA SATELLITE,...
This program involves analysis and interpretation of results from GINGA Large Area Counter (LAC) observations from a group of large stellar x-ray flares. All LAC data are re-extracted using the standard Hayashida method of LAC background subtraction and analyzed using various models available with the XSPEC spectral fitting program. Temperature-emission measure histories are available for a total of 5 flares observed by GINGA. These will be used to compare physical parameters of these flares...
Topics: NASA Technical Reports Server (NTRS), EMISSION SPECTRA, SPECTRUM ANALYSIS, STELLAR FLARES, STELLAR...
The following publications are included and serve as the final report: The X-ray Spectrum of Abell 665; Clusters of Galaxies; Ginga Observation of an Oxygen-rich Supernova Remnant; Ginga Observations of the Coma Cluster and Studies of the Spatial Distribution of Iron; A Measurement of the Hubble Constant from the X-ray Properties and the Sunyaev-Zel'dovich Effect of Abell 2218; Non-polytropic Model for the Coma Cluster; and Abundance Gradients in Cooling Flow Clusters: Ginga LAC (Large Area...
Topics: NASA Technical Reports Server (NTRS), GALACTIC CLUSTERS, SUPERNOVA REMNANTS, X RAY SPECTRA,...
The goal of this proposal was to observe with ASCA, YY Dra, a DQ Her objected identified using archival Ginga data, in order to complete a high quality ASCA study of Ginga-detected DQ Her stars. There are relatively few DQ Her objects characterized by X-ray pulsations at the white dwarf spin period and optical pulsations at the orbital period and extremely complex X-ray spectra. The ASCA study included seven DQ Her objects. ASCA is able to resolve separate components of the Fe K emission and to...
Topics: NASA Technical Reports Server (NTRS), X RAY SPECTRA, COLD GAS, HELIUM, HYDROGEN, UNSTEADY FLOW,...
The pulse-timing projects supported by NASA Grant NAG8-695 were motivated in large part by our long-standing interest in the physics of rotating neutron stars and particularly the variations in rotation due to internal and external fluctuating torques. For accretion-powered pulsars, observed as compact galactic X-ray sources, our work has been motivated by questions regarding the physics of matter accretion, mass transfer, and mass loss in these X-ray binary systems. For rotation-powered...
Topics: NASA Technical Reports Server (NTRS), GALAXIES, GINGA SATELLITE, MASS TRANSFER, PULSARS, STELLAR...
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May 26, 2011
05/11
by
Davis, R. H
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The focus of the symposium was on multiparticle hydrodynamic interactions which lead to fluctuating motion of the particles and resulting particle migration and dispersion or diffusion. Implications of these phenomena were described for sedimentation, fluidization, suspension flows, granular flows, and fiber suspensions. Computer simulation techniques as well as experimental techniques were described. Each session had an invited leadoff talk which overviewed the session topic as well as...
Topics: GAMMA RAYS, STELLAR MASS, STABILITY, PAIR PRODUCTION, OPTICAL THICKNESS, LINE OF SIGHT, GINGA...
This is the final report to the National Aeronautics and Space Administration (NASA) concerning NASA grant NAG8-697. This grant was awarded to Dr. C. Megan Urry of the Space Telescope Science Institute in response to a proposal, entitled 'X-Ray Temporal and Spectral Studies of Blazars with the Ginga Satellite', to collaborate with Japanese colleagues in using the Ginga X-ray satellite. The grant was originally awarded on 2/27/88 and expired on 3/31/94. The Ginga X-ray satellite had...
Topics: NASA Technical Reports Server (NTRS), ACTIVE GALACTIC NUCLEI, ASTROPHYSICS, BLAZARS, LUMINOSITY,...
The x-ray phenomena of the binary system SMC X-1/Sk 160, observed with the Ginga and ROSAT x-ray observatories, are compared with computed phenomena derived from a three dimensional hydrodynamical model of the stellar wind perturbed by x-ray heating and ionization which is described in the accompanying paper. In the model the BOI primary star has a line-driven stellar wind in the region of the x-ray shadow and a thermal wind in the region heated by x-rays. We find general agreement between the...
Topics: NASA Technical Reports Server (NTRS), ECLIPSING BINARY STARS, STELLAR ENVELOPES, STELLAR MODELS,...
We develop a general expression for the gamma - gamma absorption coefficient, alpha(sub gamma(gamma)) for gamma-rays propagating in an arbitrary direction at an arbitrary point in space above an X-ray-emitting accretion disk. The X-ray intensity is assumed to vary as a power law in energy and radius between the outer disk radius, R(sub 0), and the inner radius, R(sub ms) which is the radius of marginal stability for a Schwarzschild black hole. We use our result for alpha(sub gamma(gamma)) to...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAYS, BLAZARS, COLLIMATION, COMPUTATION, X RAYS,...
SN1006 [4] and Cas A [1, 9] supernova remnants have been shown convincingly to have a hard X-ray power-law continuum. This continuum is thought to be the synchrotron radiation from accelerated electrons of approx. 100 TeV at the shock fronts. Our goal of AO2 RXTE observation is to detect the hard X-ray continuum and to determine the nature of the continuum from Tycho SNR. A detection of a power-law continuum from Tycho SNR can strongly argue for SNRs are the source of cosmic rays with the first...
Topics: NASA Technical Reports Server (NTRS), SUPERNOVA REMNANTS, COSMIC RAYS, BREMSSTRAHLUNG, NEUTRON...
We present analyses of two Ginga observations and two observations from the ROSAT database of NGC 7469, focusing on the spectral variability observed on timescales of days and longer. During the 1988 Ginga observation, the hardness ratio (8-21 keV/3.4-5.7 keV) increased significantly as the total flux decreased by 30%. As the spectrum is well fit by the reflection model and since the spectra variability dominates the higher energy band, this could be explained by either a variation in the power...
Topics: NASA Technical Reports Server (NTRS), SEYFERT GALAXIES, X RAY SPECTRA, VARIABILITY, SATELLITE...
LMC X-1 and LMC X-3 are the only two black holes that are consistently seen in the soft X-ray state. We present the results from the spectral and temporal analysis of a long (150 ksec) observation of these two objects. The spectra can be well described by a disk black body plus a high energy power-law, which extends to at least 50keV. Starting in December 1996 we have also monitored these objects with RXTE in about three to four week intervals. We present the evolution of the spectral...
Topics: NASA Technical Reports Server (NTRS), ACCRETION DISKS, BLACK HOLES (ASTRONOMY), X RAY ASTRONOMY,...
This grant supported study of cyclotron scattering lines in the spectra of gamma-ray bursts through analysis of Ginga and HEAO-1 archival data, and modeling of the results in terms of radiation transfer calculations of cyclotron scattering in a strong magnetic field. A Monte Carlo radiation transfer code with which we are able to calculate the expected properties of cyclotron scattering lines in the spectra of gamma-ray bursts was developed. The extensive software necessary in order to carry...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, GAMMA RAY SPECTRA, MAGNETIC FIELDS, MONTE...
