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NASA NTRS1983

The need for an intermediate mass scale in GUTs

The minimal SU(5) grand unified field theory (GUT) model fails to resolve the strong charge parity (CP) problem, suffers from the cosmological monopole problem, sheds no light on the nature of the 'dark' mass in the universe, and predicts an unacceptably low value for the baryon asymmetry. All these problems can be overcome in suitable grand unified axion models with an intermediate mass scale of about 10 to the 11th power to 10 to the 12th power GeV. An example based on the gauge group SO(10) is presented. Among other things, it predicts that the axions comprise the 'dark' mass in the universe, and that there exists a galactic monopole flux of 10 to the -8th power to 10 to the -7th power/sq cm/yr. Other topics that are briefly discussed include proton decay, family symmetry, neutrino masses and the gauge hierarchy problem.

Shafi, Q.↗

NASA NTRS1982

A new intermediate Seyfert galaxy - X-ray, optical, and radio properties

It is shown that the X-ray source X0459 + 034 is a Seyfert galaxy of intermediate type, and optical spectroscopy and radio observations were performed to study the nature of the object. The object appears almost stellar and slightly diffuse on Palomar Sky Survey prints. The source is identified as a Type 1.5 Seyfert with broad and narrow line components of redshift 0.016 + or - 0.001, according to H-Beta line profile. In addition, the broad line component H-Beta equivalent width is larger than that of the narrow line component by a factor of three. Finally, it is shown that this is a weak radio source with a steep nonthermal spectrum and an angular extent of approximately 3 in., and the composite radio-to-X-ray spectrum suggests that in different spectral regions, different relativistic electron populations or emission mechanisms are contributing factors.

Ghigo, F. D.↗

NASA NTRS1983

Line broadening in multiphoton processes with a resonant intermediate transition

It is found that the line width of the excitation spectrum for multiphoton ionization is broadened much more severely than the cascade fluorescence originating from the resonant intermediate level. These results derive from the mutual effects of the ionizing and resonating transitions, which are not properly accounted for in perturbative treatments. In general, the ionization line shape can be expressed as the sum of two Lorentzian components, each with different degrees of broadening. This line shape reduces to that of the resonating transition in the limit of vanishing intensities. Moreover, the fluorescence line shape may also exhibit a second component whose amplitude may become important under certain conditions.

Wang, C. C.↗

NASA NTRS1983

Optimal symmetric flight with an intermediate vehicle model

Optimal flight in the vertical plane with a vehicle model intermediate in complexity between the point-mass and energy models is studied. Flight-path angle takes on the role of a control variable. Range-open problems feature subarcs of vertical flight and singular subarcs. The class of altitude-speed-range-time optimization problems with fuel expenditure unspecified is investigated and some interesting phenomena uncovered. The maximum-lift-to-drag glide appears as part of the family, final-time-open, with appropriate initial and terminal transient exceeding level-flight drag, some members exhibiting oscillations. Oscillatory paths generally fail the Jacobi test for durations exceeding a period and furnish a minimum only for short-duration problems.

Menon, P. K. A.↗

NASA NTRS1984

Intermediate energy proton stopping power for hydrogen molecules and monoatomic helium gas

Stopping power in the intermediate energy region (100 keV to 1 MeV) was investigated, based on the work of Lindhard and Winther, and on the local plasma model. The theory is applied to calculate stopping power of hydrogen molecules and helium gas for protons of energy ranging from 100 keV to 2.5 MeV. Agreement with the experimental data is found to be within 10 percent.

Xu, Y. J.↗

NASA NTRS1984

Ages of intermediate-age Magellanic Cloud star clusters

Ages of intermediate-age Large Magellanic Cloud star clusters have been estimated without locating the faint, unevolved portion of cluster main sequences. Six clusters with established color-magnitude diagrams were selected for study: SL 868, NGC 1783, NGC 1868, NGC 2121, NGC 2209, and NGC 2231. Since red giant photometry is more accurate than the necessarily fainter main-sequence photometry, the distributions of red giants on the cluster color-magnitude diagrams were compared to a grid of 33 stellar evolutionary tracks, evolved from the main sequence through core-helium exhaustion, spanning the expected mass and metallicity range for Magellanic Cloud cluster red giants. The time-dependent behavior of the luminosity of the model red giants was used to estimate cluster ages from the observed cluster red giant luminosities. Except for the possibility of SL 868 being an old globular cluster, all clusters studied were found to have ages less than 10 to the 9th yr. It is concluded that there is currently no substantial evidence for a major cluster population of large, populous clusters greater than 10 to the 9th yr old in the Large Magellanic Cloud.

Flower, P. J.↗

NASA NTRS1984

Intermediate energy proton stopping power for hydrogen molecules and monoatomic helium gas

Xu, Y. J.↗

NASA NTRS1984

Intermediate load modules for test and evaluation

Photovoltaic modules were tested for qualification. Tests involved the following: (1) delivery of 20 solar cells for use as reference cells; (2) module documentation and inspection plans specifying the 10 Group I modules; (3) design review of module documentation from Group I modules; (4) revise module documentation to overcome any problems of deficiencies associated with the Group I modules; (5) delivery of 10 Group II modules built to revised specifications; (6) testing of Group II modules to the criteria as outlined in qualification specification. It is found that the solarvolt MSP43E40B satisfies the design criteria of qualification specification for intermediate load modules. Design changes were made in the Group I modules to overcome the deficiencies which allowed Group II modules to pass the qualification tests.

Source record↗

NASA NTRS1984

Observations of Intermediate-degree Solar Oscillations

A progress report on observations of intermediate degree oscillations is presented. Frequencies of zonal p-mode oscillations with amplitudes in excess of approx are found. 2 cm/s. These frequencies show systematic disagreement with recent theoretical calculations. The frequencies with asymptotic formula estimates are examined. Small scatter is obtained for low degree modes but large scatter at large degree. A first look at sectoral harmonic observations shows that magnetic active regions provide a major signal at low frequencies.

Harvey, J. W.↗

NASA NTRS1984

An Excitation Mechanism for Solar 5-minute Oscillations of Intermediate and High Degree

The overstability of acoustic modes trapped in the solar convection zone is studied with mechanical and thermal effects of turbulence included, in an approximate manner, through the eddy transport coefficients. Many of these acoustic modes are found to be overstable with the most rapidly growing modes occupying a region centered around 3.2 mHz and spread over a wide range of length-scales. The numerical results are in reasonable accord with the observed power-spectrum of the five-minute oscillations of intermediate and high degree. The oscillations are probably driven by a simultaneous operation of the kappa-mechanism and the turbulent conduction (convective Cowling) mechanism, the dominant contribution to the generation of self-excited acoustic waves arising from the convective Cowling mechanism.

Antia, H. M.↗

NASA NTRS1984

Intermediate-wavelength magnetic anomalies over the central Pacific

A technique to extract the intermediate wavelength anomaly field from random ship tracks has been developed and is applied to extract the field from marine survey data of the central Pacific in the band pass of 4000-400 km. The technique minimizes the effects of external field sources, secular variation, and strike aliasing. The derived data field is compared to the equivalent MAGSAT data set, and it is shown that anomalies observed in both fields are correlatable to geologic features within the oceanic lithosphere but differ in amplitude by a factor of two. Likely sources for this discrepancy are identified. It is also shown that remanent magnetization of the central Pacific seamounts produces negative magnetic anomalies which are observed at satellite altitude.

Labrecque, J. L.↗

NASA NTRS1985

The ultraviolet spectra of intermediate-redshift quasars

In the present sample of 21 intermediate redshift quasars, for which IUE Lyman-alpha line flux and UV continuum observations have been conducted, an extrapolation of the continuum to the X-ray region is noted to fall at least 2-sigma above the measured X-ray flux, at 2 keV, for two-thirds of the sample. The strength of Lyman-alpha is well correlated with the luminosity at 1450 A, and an estimate of the covering factor on the basis of the ratio of the number of Lyman-alpha to ionizing protons yields a value for the sample which, at about 0.17, is consistent with the number of observed Lyman discontinuities.

Kinney, A. L.↗

NASA NTRS1985

An ab initio investigation of possible intermediates in the reaction of the hydroxyl and hydroperoxyl radicals

Ab initio quantum chemical techniques are used to investigate covalently-bonded and hydrogen-bonded species that may be important intermediates in the reaction of hydroxyl and hydroperoxyl radicals. Stable structures of both types are identified. Basis sets of polarized double zeta quality and large scale configuration interaction wave functions are utilized. Based on electronic energies, the covalently bonded HOOOH species is 26.4 kcal/mol more stable than the OH and HO2 radicals. Similarly, the hydrogen bonded HO---HO2 species has an electronic energy 4.7 kcal/mol below that of the component radicals, after correction is made for the basis set superposition error. The hydrogen bonded form is planar, possesses one relatively normal hydrogen bond, and has the lowest energy 3A' and 1A' states that are essentially degenerate. The 1A" and 3A" excited states produced by rotation of the unpaired OH electron into the molecular plane are very slightly bound.

Jackels, C. F.↗

NASA NTRS1986

Stability analysis of intermediate boundary conditions in approximate factorization schemes

The paper discusses the role of the intermediate boundary condition in the AF2 scheme used by Holst for simulation of the transonic full potential equation. It is shown that the treatment suggested by Holst led to a restriction on the time step and ways to overcome this restriction are suggested. The discussion is based on the theory developed by Gustafsson, Kreiss, and Sundstrom and also on the von Neumann method.

South, J. C., Jr.↗

NASA NTRS1986

The intermediate comets and nongravitational effects

The motions of the intermediate-period comets Pons-Brooks, Olbers, Brorsen-Metcalf, and Westphal are investigated over their observed intervals. The three apparitions of comets Pons-Brooks and Olbers were successfully linked, using the now standard nongravitational-force model. The two apparitions of Comet Brorsen-Metcalf were successfully linked without the need for nongravitational effects. For the 1852 and 1913 apparitions of Comet Westphal, complete success was not achieved in modeling the comet's motion either with or without nongravitational effects. However, by including these effects, the comet's astrometric observations could be represented significantly better than if they were assumed inoperative. Comet Westphal's dynamic and photometric behavior suggests its complete disintegration before reaching perihelion in 1913. If the very large radial nongravitational parameter determined for Comet Westphal is due to the comet's disintegration into dust, then the resultant dust-particle size is of the order of 0.8 mm.

Yeomans, D. K.↗

NASA NTRS1986

An ab initio investigation of possible intermediates in the reaction of the hydroxyl and hydroperoxyl radicals

Ab initio quantum chemical techniques have been used to investigate covalently-bonded and hydrogen-bonded species that may be important intermediates in the reaction of hydroxyl and hydroperoxyl radicals. Stable structures of both types were identified. Basic sets of polarized double-zeta quality and large scale configuration interaction wave functions have been utilized. Based upon electronic energies, the covalently-bonded HOOOH species is found to be 26.4 kcal/mol more stable than the OH and HO2 radicals. Similarly, the hydrogen-bonded HO-HO2 species is found to have an electronic energy 4.7 kcal/mol below that of the component radicals, after correction is made for the basis set superposition error. The hydrogen-bonded form is found to be planar, to possess one relatively 'normal' hydrogen bond, and to have lowest energy 3A-prime and 1A-prime states that are essentially degenerate. The 1A-double prime and 3A-double prime excited states produced by rotation of the unpaired OH electron into the molecular plane are found to be very slightly bound.

Jackels, C. F.↗

NASA NTRS1986

Three component plasma electron distribution in the intermediate ionized coma of Comet Giacobini-Zinner

The observation of three distinct components of the electron distribution function measured in the intermediate ionized coma (IIC) and plasma tail of Comet Giacobini-Zinner is reported. It is believed that the cold component represents electrons produced close to the comet nucleus by ionization of cometary matter and subsequent cooling by Coulomb collisions. The second component also appears to be composed of electrons produced by photoionization of cometary neutrals, but sufficiently far from the nucleus that the distributions are largely unaffected by Coulomb interactions. The hot component is probably a population of electrons originating in the solar wind. Throughout the IIC, the electrostatic potential of the spacecraft was very low (less than 0.8 eV), implying that ICE generated very little impact-produced plasma during its passage.

Zwickl, R. D.↗

NASA NTRS1986

An intermediate-sensitivity survey at high Galactic latitude with HEAO A-1

A 314 square degree region of sky at high galactic latitude was mapped in 0.5-20 keV X-rays using summed data from the HEAO A-1 experiment. 21 sources are detected above a 5 sigma threshold corresponding to a limiting flux of about 0.2 UFU. This limit is at a decade intermediate to those achieved in the full-sky surveys, Uhuru, Ariel 5, and the HEAO A-2 experiment, and to those achieved in the Einstein partial-sky surveys. The HEAO A-1 detectors also complement these other instruments in terms of spectral response characteristics. A table of source intensities and positional error boxes for the 21 source detections is presented. A graphical representation of the positional error boxes is also presented. Identifications for 14 sources are proposed. A number-flux curve representing all high galactic latitude X-ray sources detected with HEAO A-1 has been constructed. The number-flux curve appears to be consistent with d log N/d log S = -1.5.

Shrader, C. R.↗