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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Ionization nebulae surrounding CAL 83 and other supersoft X-ray sources

We present the results of an optical search for ionized gaseous nebulae surrounding luminous, 'supersoft' X-ray sources in the Large and Small Magellanic Clouds. This relatively new and mysterious X-ray class has characteristic luminosities approximately 10(exp 37)-10(exp 38) ergs/s with effective temperatures in the range of 2-6 x 10(exp 5) K. The presence of a large flux of UV and soft X-ray photons from these objects has led to predictions of bright optical emission lines from the local interstellar medium. One such object, CAL 83 in the LMC, was known to have an associated nebula, and we quantify here the asymmetry and luminosity of this remarkable nebula. Deep images were made using narowband filters to isolate the emission lines of H alpha and (O III) (lambda 5007). In these emission lines, the nebula is detected out to distances as far as 25 pc from the central object, and the integrated luminositu in each line is of order approximately 100 solar luminosity. Model calculations of such nebulae for chemical abundances characteristic of the LMC indicate that approximately 1% of the X-ray luminosity of the central source is reprocessed into the nebular H-alpha and (O III) lambda 5007 emission lines, from which we conclude that the time-averaged X-ray luminosity of the central source, CAL 83, is greater than 3 x 10(exp 37) ergs/s. The bright inner nebula contains approximately 150 solar mass within 7.5 pc of CAL 83, which clearly indicates that the nebular material has its origin in the interstelar medium. In sharp contrast, there were null detections for nebulae associated with nine other luminous, supersoft X-ray sources in the LMC and SMC, with upper limits for the (O III) luminosity that are a factor of approximately 10 below that for CAL 83. For eight of these latter sources, we conclude that either their time-averaged luminosity is substantially below that of CAL 83, or that the local interstellar medium is much less dense. The latter effect may be enhanced by expansion of the ionized nebula during the last several million years.

Remillard, R. A.↗
NASA NTRS1995

Ionization Nebulae Surrounding CAL 83 and Other Supersoft X-ray Sources

We present the results of an optical search for ionized gaseous nebulae surrounding luminous, "supersoft" X-ray sources in the Large and Small Magellanic Clouds. This relatively new and mysterious X-ray class has characteristic luminosities approximately 10(exp 37) - 10(exp 38) ergs/s with effective temperatures in the range of 2 - 6 x 10(exp 5) K. The presence of a large flux of UV and soft X-ray photons from these objects has led to predictions of bright optical emission lines from the local interstellar medium. One such object, CAL 83 in the LMC, was known to have an associated nebula, and we quantify here the asymmetry and luminosity of this remarkable nebula. Deep images were made using narrowband filters to isolate the emission lines of H.alpha and [O III] (lamda5007). In these emission lines, the nebula is detected out to distances as far as 25 pc from the central object, and the integrated luminosity in each line is of order approximately 100 solar luminosity. Model calculations of such nebulae for chemical abundances characteristic of the LMC indicate that approximately 1% of the X-ray luminosity of the central source is reprocessed into the nebular H.alpha and [O III] lamda5007 emission lines, from which we conclude that the time-averaged X-ray luminosity of the central source, CAL 83, is greater than 3 x 10(exp 37) ergs/s. The bright inner nebula contains approximately 150 solar mass within 7.5 pc of CAL 83, which clearly indicates that the nebular material has its origin in the interstellar medium. In sharp contrast, there were null detections for nebulae associated with nine other luminous, supersoft X-ray sources in the LMC and SMC, with upper limits for the [O III] luminosity that are a factor of approximately 10 below that for CAL 83. For eight of these latter sources, we conclude that either their time-averaged luminosity is substantially below that of CAL 83, or that the local interstellar medium is much less dense. The latter effect may be enhanced by expansion of the ionized nebula during the last several million years.

Remillard, R. A.↗
NASA NTRS1990

Data Management Standards in Computer-aided Acquisition and Logistic Support (CALS)

Viewgraphs and discussion on data management standards in computer-aided acquisition and logistic support (CALS) are presented. CALS is intended to reduce cost, increase quality, and improve timeliness of weapon system acquisition and support by greatly improving the flow of technical information. The phase 2 standards, industrial environment, are discussed. The information resource dictionary system (IRDS) is described.

Jefferson, David K.↗
NASA NTRS1993

The X-ray eclipse of the LMC binary CAL 87

ROSAT-PSPC observations of the LMC eclipsing binary CAL 87 show a short-duration, shallow X-ray eclipse which coincides in phase with the primary optical minimum. Characteristics of the eclipse suggest the X-ray emitting region is only partially occulted. Similarities with the eclipse of the accretion-disk corona in X 1822-37 are discussed. However, no temperature variation through eclipse is found for CAL 87. A revised orbital period, combining published data and recent optical photometry, is given.

Schmidtke, P. C.↗
NASA NTRS2007

A Discussion on Personnel Exposure to Posttest Byproducts from a 50-cal. Light Gas Gun

In January of 2002, employees working in the Hypervelocity Test Facility (HTF) at White Sands Test Facility (WSTF) began to notice common physical complaints. These included loss of smell, loss of taste, skin irritation, a burning sensation of the mucus membranes, and redness and chapping of the lips. These conditions extended to home during the weekends and throughout holiday breaks as well. Concerns about air contaminants were raised with regard to the operation of the .50-cal. two-stage light gas gun (2SLGG). Employees suspected that these conditions might be caused by air contaminants from small leaks at the gun pump tube joint at the breech, and exhaust gas entrainment into the WAC systems. The WSTF Industrial Hygienist (IH) was notified and samples were collected using the MIRAN infrared spectrometer (real time) air sampler on 08 January 2002 at the SO-cal. gun. The results from this screening test suggested the need for more detailed investigations with analytical sampling and analysis.

Henderson, Don↗
NASA NTRS2010

Experiment of Injecting Phase Cal Ahead of the Feed: First Results

For developing the Russian VLBI network of new generation, a few experiments of injecting the phase calibration signal ahead of the feed were carried out. In the experiments an external broadband phase calibration signal was emitted through a special feed to a receiver horn directly. Prototypes of the feed for a frequency range of 2-18 GHz were created. The first experiments on injection phase cal ahead of the feed were carried out at Svetloe Observatory of the QUASAR VLBI network. The phase cal signal was emitted by the broadband feed installed on the roof of a mirror cabin, reflected by the sub-reflector, and received by the horn of the receiving system. The results of these experiments are considered.

Ivanov, Dmitrij↗
NASA NTRS1987

Cal Poly Space Project G-279

The Cal Poly Space Project is an effort on the part of several highly motivated students to deploy a space canister which will examine the effects of microgravity on electroplating and immiscible metals. The experiments will be controlled and monitored by a specialized triple redundancy system developed to defer the possible electronic errors due to uncontrollable factors such as photons from the Sun. With the finalization of the payload design and the near completion of the data control system, the integration phase of the project is anticipated to be completed and the project ready for launching by early 1987. It is hoped that the experiments will lead to new insights in space research and also prove profitable to industry.

Farley, David R.↗
NASA NTRS1990

Aerodynamic design of the Cal Poly Da Vinci Human-Powered Helicopter

This paper will discuss the methodology used in designing the rotor and drive propellers for the third generation Cal Poly Da Vinci Human-Powered Helicopter. The rotor was designed using a lifting surface, uniform inflow hover analysis code and the propeller was designed using a minimum induced-loss method. Construction, geometry, and operating considerations are discussed as they impact the designs. Optimization of the design performance is also explained. The propellers were tested in a wind tunnel and results are compared with theoretical data. Successful flight tests of the Da Vinci III are discussed.

Larwood, Scott↗
NASA NTRS1993

The Cal Poly aircraft design program

Discussed is the aircraft design program at Cal Poly, SLO. The history of the program and the impact of the NASA/USRA ADP are presented. Examples of student design accomplishments are included. Questions on how the aircraft design education process can be improved are postulated.

Sandlin, Doral R.↗
NASA NTRS2000

A High Resolution Spectroscopic Observation of CAL 83 with XMM-Newton/RGS

We present the first high resolution photospheric X-ray spectrum of a Supersoft X-ray Source, the famous CAL 83 in the Large Magellanic Cloud. The spectrum was obtained with the Reflection Grating Spectrometer on XMM-Newton during the Calibration/Performance Verification phase of the observatory. The spectrum covers the range 20-40 A at an approximately constant resolution of 0.05 A, and shows very significant, intricate detail, that is very sensitive to the physical properties of the object. We present the results of an initial investigation of the spectrum, from which we draw the conclusion that the spectral structure is probably dominated by numerous absorption features due to transitions in the Gshells of the mid-2 elements and the M-shell of Fe, in addition to a few strong K-shell features due to CNO.

Paerels, Frits↗
NASA NTRS1955

Chemical and Physical Properties of Hi-Cal-2

As part of the Navy Project Zip to consider various boron-containing materials as possible high-energy fuels, the chemical and physical properties of Hi-Cal-2 prepared by the Callery Chemical Company were evaluated at the NACA Lewis laboratory. Elemental chemical analysis, heat of combustion, vapor pressure and decomposition, freezing point, density, self ignition temperature, flash point, and blow-out velocity were determined for the fuel. Although the precision of measurement of these properties was not equal to that obtained for hydrocarbons, this special release research memorandum was prepared to make the data available as soon as possible.

Spakowski, A. E.↗
NASA NTRSDate not supplied

Cal X-1, a Pioneer mission for absolute in-orbit flux calibration for current and future X-ray observatories

X-ray astronomy missions are now making observations capable of answering fundamental physics and cosmology questions. However, those studies are often limited by lack of absolute X-ray flux calibration; the most powerful X-ray observatories reveal discrepancies in the source fluxes at the 10-20% level. These discrepancies are plausibly related to changes in the instrument performance between the ground calibration and the orbit. We propose to overcome this problem by establishing "standard candles" in the X-ray sky. Our Cal X-1 mission, a Pioneer concept, will consist of 2 small satellites flying in tandem. One will have an X-ray telescope and the other, a pair of absolutely-calibrated X-ray sources (E=1.5 keV and 6 keV). The telescope will ping-pong between the source satellite and several well-chosen constant celestial sources, determining the accurate fluxes of those sources and turning them into standard candles for all other X-ray observatories, current and future.

Maxim Markevitch↗