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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 577 records · Page 32

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NASA NTRS1974

A search for solar neutrons from 10-100 MeV

A search for solar neutrons is reported from a balloon flight launched from Palestine, Texas on Sept. 26, 1971. The sun was observed from 8:30 to 19:30 CST. The neutrons were detected with a telescope consisting of two 0.5 sq m scintillation detectors spaced 1 meter apart using a double-scattering/time-of-flight technique. Upper limits for solar neutrons in the energy intervals 10 to 30, 30 to 50, and 50 to 100 MeV are .00011, .00026 and .00059 neutron/sq cm-sec, respectively. These are combined into an overall upper limit of .00051 neutron/sq cm-sec.

Monn, S.↗

NASA NTRS1974

A search for Lyman-alpha emission in beta Lyrae from Copernicus

High-resolution (0.2 A) spectrophotometric observations of the complex eclipsing binary beta Lyrae were obtained with the Princeton Telescope Spectrometer on the Copernicus satellite. We discuss the search for L-alpha emission in beta Lyrae and compare the Copernicus results with the OAO-2 observations of the same binary system. The possible L-alpha emission features observed from OAO-2 are identified as blends of the emission lines of other elements in the vicinity of L-alpha.

Kondo, Y.↗

NASA NTRS1974

Search for deuterium in Orion and detection of high-velocity features

Results of a search for D alpha emission near the bright H alpha line in Orion. The observations revealed a high-velocity H alpha feature near -60 km/sec, whose intensity varied across the nebula, ranging from 0.005 to 0.005 relative to H alpha; another much weaker feature, possibly also H alpha, was observed at about -100 km/sec. Because these high-velocity H alpha features partially overlap the expected position of D alpha, only an upper limit D/H less than .00013 for the number ratio in Orion can be derived.

Traub, W. A.↗

NASA NTRS1974

Search for celestial X-ray bursts

Progress in two experimental programs is reported. One program involves the search through satellite data for existing evidence for fast photon intensity bursts with energies exceeding 80 keV. The second program is concerned with the development of very sensitive instrumentation to make possible studies of X-ray and gamma ray bursts in the region from 0.1 to 15 MeV with angular resolution, energy resolution, and time resolution, taking into account the complete dynamic range from several nanoseconds to several hours.

Cline, T. L.↗

NASA NTRS1974

Search for gamma ray lines from supernovae and supernova remnants

A gamma ray monitor with a NaI crystal shielded with a cup-shaped CsI cover was contained in the rotating wheel compartment of the OSO-7 spacecraft for measuring the gamma ray spectra from 0.3 to 10 MeV in search for gamma ray lines from a possible remnant in the Gum Nebula and the apparent Type I supernovae in NGC5253. A brief analysis of data yielded no positive indications for X-rays, gamma ray lines, or continuum from these sources.

Chupp, E. L.↗

NASA NTRS1974

A search for a cosmological component of the soft X-ray background in the direction of M31

Results of an experiment to search for absorption of the soft diffuse X-ray background by M31, the Andromeda Nebula, are presented. Both X-ray and 21-cm observations were obtained with high spatial resolution; the X-ray detector had a 2-degree field of view, and the 21-cm data were taken with 20-minute resolution. The results establish that at least 48 percent of the soft X-ray flux has a local source, but that the remainder may be of distant origin and therefore of cosmological significance.

Margon, B.↗

NASA NTRS1975

A search for X-rays from UV Ceti flare stars

A search of MIT/OSO-7 data was made for evidence of X-ray emission from flares of UV Ceti flare stars. Observations from McDonald Observatory were used to identify the times of optical flares. The only instance of coincident coverage occurred on 1974 January 21 UT at 03:43:26 GMT for delta m(u)=0.86 flare of YZ CMi. No radio coverage of this particular event was obtained. Upper limits (3 sigma) of 0.8, 1.0, and 0.7 photons/sq cm-sec on the observed X-ray flux were set for the energy ranges greater than or approximately equal to 15, greater than or approximately equal to 3, and 1-10 keV, respectively.

Crannell, C. J.↗

NASA NTRS1974

A search for posteclipse brightening of Io in 1973. II

Four eclipse reappearances of Io were observed with an area-scanning photometer during the 1973 apparition of Jupiter. The results of these observations and of the ones reported in the preceding paper are discussed in the context of recent physical models for posteclipse brightening. An evaluation of the relative merits and deficiencies of all observational techniques which have been used to search for posteclipse brightening of Io leads to the conclusion that the reality of this phenomenon remains very much in doubt.

Franz, O. G.↗

NASA NTRS1974

A search for soft X-ray emission from red-giant coronae

Hills has pointed out that if red-giant coronae are weak sources of soft X-rays, then the problems of the identification of the local component of the soft X-ray background and the observed lack of gas in globular clusters may be simultaneously resolved. Using instrumentation aboard OAO Copernicus, we have searched unsuccessfully for emission in the 10-100 A band from four nearby red giants. In all cases, our upper limits are of the order of the minimum theoretically predicted fluxes.

Margon, B.↗

NASA NTRS1974

A search for H2O and CH4 in Comet Kohoutek

A spectroscopic search for H2O and CH4 in Comet Kohoutek (1973f) was made using a Pepsios interferometer. No evidence was found for either molecule, allowing to set an upper limit on their production rates (on about Jan. 21, 1974) of Q(H2O) less than 6.2 times 10 to the 28th power per sec and Q(CH4) less than 20 times 10 to the 30th power per sec.

Traub, W. A.↗

NASA NTRS1974

Molecule searches in Comet Kohoutek /1973f/ at microwave frequencies

Nine transitions of the possible parent molecules H2O, NH3, CH3OH and N2O as well as the OH radical were searched for in Comet Kohoutek (1973f) in the frequency range 22.2-25.2 GHz. These molecules were not detected, but the upper limits for the optical depth, mean column density and the production rate are derived for each of the molecules. These results are discussed and compared with the reported detections of HCN and CH3CN emission and OH absorption.

Mango, S. A.↗

NASA NTRS1974

A search for microwave emission from CH in Comet Kohoutek /1973f/

A search was conducted for the three 9-cm transitions of the ground state Lambda-doublet of CH in comet Kohoutek, using the CSIRO 64-m radio telescope and the Onsala Space Observatory's 25.6-m telescope. No lines were detected during the observing periods, and upper limits are given for the corresponding antenna temperatures.

Rydbeck, O. E. H.↗

NASA NTRS1975

A search for lunar tides in the thermosphere

A search for lunar tides in densities derived from satellite drag has yielded spurious oscillations with the period of one lunar day, caused by the '27-day' variation connected with the solar rotation. The real tides remain undetected, with an amplitude smaller than 1 or 2%.

Jacchia, L. G.↗

NASA NTRS1975

A search for H/-/ in the shell surrounding chi Ophiuchi

Assuming that chi Oph is an extreme Be star, some consequences are investigated for the interpretation that the IR excesses in such stars are produced by H(-) free-bound emission. The column density of H(-) in the shell surrounding chi Oph is estimated from the observed IR excess, and Copernicus UV spectrophotometric data are used to search for a predicted absorption feature at 1129.54 A due to H(-) and to derive an upper limit to the H(-) column density. No feature resembling the predicted H(-) line is seen in the spectrum of chi Oph, and a marked discrepancy is noted between the estimated column density and the derived upper limit. Possible causes of these discrepancies are discussed, including incorrect interpretation of the IR excess in extreme Be stars, incorrect theoretical calculations describing the predicted H(-) UV absorption line, and the possibility that the line of sight through the shell does not intersect the regions where the IR excess originates.

Snow, T. P., Jr.↗

NASA NTRS1975

Search for cosmic-ray antimatter

It appears probable that some fraction of the cosmic rays has extragalactic origin. A search for antimatter nuclei was conducted with the aid of a balloon-borne superconducting magnetic spectrometer. The investigation made use of the fact that matter and antimatter nuclei, because of their opposite signs of charge, would be deflected in opposite directions when passing through a magnetic field. The antimatter flux limits set by the experiments are discussed.

Smoot, G. F.↗

NASA NTRS1975

Search for monenergetic gamma rays from psi /3684/ decay

Results are reported of a search for monoenergetic gamma rays with energies above 50 MeV arising from psi (3684) decay. The measurements were made by operating an electron-positron storage ring at a center-of-mass energy of 3684 MeV and detecting the secondary gamma rays with large-crystal NaI(T1) spectrometers. No significant evidence is found for the emission of such radiation, and upper limits are placed on such emissions for energies above 50 MeV.

Simpson, J. W.↗

NASA NTRS1975

A search for optical pulsations from X-ray sources near 4640-4650 A and 4686 A

We have searched for periodic optical pulsations from Cyg X-1, Cyg X-2, 3 U 1700 - 37, Her X-1, Sco X-1, Vela X-1, SMC X-1, WRA 977, and from the central region of the Cygnus Loop. Most observations were confined to the spectral features around 4640-4650 A and 4686 A, which are seen in most X-ray source counterparts, are known to be variable, and are likely to be associated with the X-ray emission. No optical pulsations were detected, but upper limits are established and related to the X-ray behavior.

Canizares, C. R.↗

NASA NTRS1976

Search for and analysis of radioactive halos in lunar material

The lunar halo search was conducted because halos in terrestrial minerals serve as pointers to localized radioactivity, and make possible analytical studies on the problems of isotopic dating and mode of crystallization of the host mineral. Ancillary studies were conducted on terrestrial halos and on certain samples of special origin such as tektites and meteorites.

Gentry, R. V.↗