ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • ASTROPHYSICS
  • 1970-1974  (166)
  • 1
    Publication Date: 2006-01-11
    Description: Experimental determination of the paired interaction potential of atoms and molecules composing the atmospheres of the earth and the planets is described.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 275-281
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2006-01-11
    Description: Research on the primary cosmic radiation and solar cosmic rays from the Luna 10, 11, and 12 artificial lunar satellites is reviewed. Data on the vertical distribution of cosmic rays above the moon's surface are presented, and the albedo for the primary radiation is determined. The fluxes of electrons with energies from 30 to 300 keV were registered in the solar cosmic rays. Rapid variations of the electron flux were observed. The angular distributions of 0.5-10 MeV protons moving together with the corpuscular streams responsible for Forbush decreases were investigated.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 151-173
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2006-01-11
    Description: Research on the fine structure of the interplanetary medium is reviewed. The characteristics of shock waves, filaments, and contact surfaces according to space probe measurements are discussed.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 103-123
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2006-01-11
    Description: The problem of quasistationary high frequency Langmuir turbulence, which is one of the types of turbulence encountered in the cosmic plasma, is examined theoretically.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 83-102
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2006-01-11
    Description: Interaction studies of a plasma stream with a magnetic dipole have shown that the thickness of the plasma/field interlayer is considerably greater than the characteristic plasma dimension c/omega sub 0. Broadening of the layer is due to the formation of a collisionless shock wave. To demonstrate collisionless dissipation, the Joulean losses were calculated using the conductivity value obtained from the skin layer thickness. Analysis of the various physical processes showed that the hypothesis of collisionless dissipation of the directional plasma flow is justified.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 59-67
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2006-01-11
    Description: A review of experimental and theoretical studies devoted to analysis of physical processes in the magnetosphere is presented. Attention is focused on the interrelationships among the most important geophysical phenomena in the magnetosphere: magnetic storms, auroras, the radiation belts, and processes in the geomagnetic tail. Recommendations are submitted for future experiments that are needed for development of a theory of magnetospheric phenomena.
    Keywords: ASTROPHYSICS
    Type: Interplanet. Medium and Phys. of the Magnetosphere (NASA-TT-F-784); p 1-33
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2011-08-16
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 37; 1, De; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2011-08-16
    Description: We have numerically studied the interaction between interstellar gas and a gravitational perturbation produced by a fluctuation in the stellar mass distribution. For a simple equation of state, shock waves develop even if the gravitational perturbation is aperiodic and transient. In a medium which can change thermal phase, shocks do not form and the gas makes a transition directly to the cold, dense phase. The cold material has an anomalous velocity imparted to it by the gravitational perturbation and it becomes an accretion front moving through the hot gas and capturing it. The accretion fronts trigger thermal phase change on a large scale and can reproduce the extent of observed cold clouds. Furthermore their high mass is favorable to gravitational instability and subsequent star formation.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 36; 2, No; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Apsidal-motion constants, k2, have been determined for models of homogeneous main-sequence stars constructed with the new 'Thomas-Fermi' opacities of Carson. These models are similar to those constructed with the 'hydrogenic' opacities of Cox and Stewart up to about 7 solar masses, but yield smaller values of k2 at higher masses. Nevertheless, the new theoretical constants are still systematically too large compared with most of the empirical constants known for members of well-observed binary systems. Uniform rotation is found to lower the theoretical constants only slightly. The effect of normal evolution during core hydrogen burning, however, produces good detailed agreement with observations. The primary of alpha Vir is probably evolving normally if Carson's opacities are adopted.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Zero-age main-sequence models for stars of 20, 10, 5, and 2 solar masses with no heavy elements are constructed for three different possible primordial helium abundances: Y=0.00, Y=0.23, and Y=0.30. The latter two values of Y bracket the range of primordial helium abundances cited by Wagoner. With the exceptions of the two 20 solar mass models that contain helium, these models are found to be self-consistent in the sense that the formation of carbon through the triple-alpha process during premain sequence contraction is not sufficient to bring the CN cycle into competition with the proton-proton chain on the ZAMS. The zero-metal models of the present study have higher surface and central temperatures, higher central densities, smaller radii, and smaller convective cores than do the population I models with the same masses.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 31; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Determinations of interplanetary sector structure for the years 1970-1972 reveal the persistence of sector patterns during the decreasing portion of the solar cycle. The simple two-sector pattern of 1969 persists through 1970 but develops greater complexity in 1971-1972.-
    Keywords: ASTROPHYSICS
    Type: Journal of Geophysical Research; 79; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2011-08-16
    Description: Slowly rotating stars which are oscillating at small amplitude in a broad spectrum of g-modes should display strong surface nonuniformities if even weak nonlinear coupling exists between the modes. Oscillatory power will be concentrated into distinctive patterns which rotate rigidly in spite of differential rotation in the outer stellar layers. Each pattern rotates at a constant rate slower than the star as a whole according to a very simple law of rotation. Virtually all the rotation rates are within 9 per cent of the stellar rate. Evidence is cited that the sun may be oscillating, so other stars along the main sequence may be oscillating, also. If zones obeying the predicted rotation law can be detected in a star, then the rotation rate of the stellar interior becomes known, and differential rotation is negligible over most of the stellar mass.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2011-08-16
    Description: Four new interstellar lines have been detected near 87.3 GHz. Based on laboratory ESR data these lines have been positively defined as hyperfine components of the lowest rotational transition of the ethynyl radical C2H. The observations gave precise values for the C2H rotation, spin-doubling, and hyperfine constants. C2H is probably one of the most abundant interstellar polyatomic molecules yet detected.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2011-08-16
    Description: The pulsational stability of massive, chemically homogeneous stars of Population I has been investigated for a range of simple opacity representations consisting of a straight sum of electron-scattering and modified Kramers opacity. The critical mass for stability against nuclear-energized pulsations is found to be extraordinarily sensitive to small changes in the coefficient and/or temperature exponent of the absorption part of the opacity law. A gradual increase in the atomic absorption (dominant near the stellar surface) first raises the critical mass, then restricts the upper mass limit for instability, and finally eliminates pulsational instability at all masses.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Particular attention is given to the physics involved in the derivation of an equation of state for a density range from 10 g/ccm to 200,000 billion g/ccm and for the density region from 200,000 billion g/ccm to 2,000,000 billion g/ccm. Conditions in a high density regime with densities exceeding 500,000 billion g/ccm are examined. Equations of state for a gas of pure neutrons and for a gas of nucleons, electrons, and hyperons are considered.
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: For comets whose nuclei are composed of water ice conglomerates it is shown that the ion H3O(+) can predominate to distances of 5000 km in the subsolar direction. Beyond this distance H2O(+) is the most important ion. The crossover point is a sensitive function of the rate of evaporation from the nucleus. The presence of ammonia or metals such as sodium, in concentrations greater than 0.1% H2O, can lead to NH4(+) and Na(+) ions.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Oct. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Metallic line-blanketing coefficients have been measured over the wavelength range from 3800 to 4700 A in a sample of 20 Am and normal A stars. An expression for the logarithmic iron abundance has been calibrated in terms of effective temperature and a mean line-blocking coefficient. This makes it possible to determine the atmospheric iron abundance in sharp-lined Am and A stars with an accuracy of better than plus or minus 0.1 dex, using only line-blocking measurements and a photometric effective temperature.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Oct. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: The cross section for Li-7 production in alpha-alpha reactions is shown to be increased by about a factor of 2 due to the excitation levels of Li-7 and Be-7 at 478 keV and 431 keV, respectively. The cross section for Li-6 production, however, remains the same as calculated on the basis of the detailed balance principle. The lines at 478 keV and 431 keV may link Li-7 production to feasible gamma-ray observations.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 34; 3, Se; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2011-08-16
    Description: The binding energy and stability of supermassive stars (SMS's) are examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordvedt. The PPN formalism encompasses the post-Newtonian limit of virtually every theory of gravity, differentiating between theories by means of nine PPN parameters. A general expression is derived for the energy integral in the PPN framework, and those theories in which the energy will be conserved are defined. In all such theories, a SMS of radius less than a critical radius will be unstable against adiabatic radial perturbations. Present experimental limits on the PPN parameters gamma and beta do not exclude the possibility of the existence of stable, non-rotating, hydrogen-burning SMS's of masses an order of magnitude larger than the upper limit for the mass of such stars predicted in general relativity.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 31; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2011-08-16
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Neutral-hydrogen absorption-line interferometer observations are reported for five continuum radio sources situated behind an extensive layer of cold interstellar H I gas. In contrast to low-spatial-resolution emission-line observations reported earlier which show the large-scale uniformity of the layer, the high-spatial-resolution absorption-line observations reveal variations in the velocity and density within the layer. The new results together with the old indicate the apparent coexistence of a large-scale mechanism for triggering the formation of cold hydrogen and an instability mechanism leading to small-scale irregularities.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: A neutrino mechanism is discussed in order to explain supernovae in massive stars. An argument is presented for supernova mass ejection through leptonic neutrino transport characteristics suppressed by the arbitrary zero chemical potential condition. Results show that lepton conservation effects may be important in supernova neutrino transport. At low temperature and density the diffusion approximation becomes less precise because of the long mean free paths of low energy neutrinos. The amount of equilibrium neutrino spectrum affected here is small over most of the collapsing supernova structure.
    Keywords: ASTROPHYSICS
    Type: Nature; 252; Nov. 22
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Publication Date: 2011-08-16
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Oct. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2011-08-16
    Description: An evolutionary sequence was calculated for a white dwarf on which a hydrogen rich envelope is assumed to increase with time. The stellar models were computed by integrating numerically the system of stellar structure equations by means of the Henyey method. The accretion of matter was assumed to be quasi-static. Near the point of the chemical discontinuity, a temperature maximum is shown to arise, and hydrogen ignites; a thin shell energy source is formed which is thermally unstable. The resulting thermal runaway was investigated numerically and by means of a simple approximation based on the energy balance in the hydrogen burning shell source.
    Keywords: ASTROPHYSICS
    Type: Astrometrics and Astrophysics, No. 17 (NASA-TT-F-15768); p 1-55
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2011-08-16
    Description: Optical parameters investigated and solved for included: (1) cloud layer albedo and cloud cover optical thickness; (2) planetary surface self-radiation influence; (3) light flux distribution as function of atmospheric height; (4) upper estimate of the observed contrasts; (5) surface optical parameters; and (6) contrast decrease with altitude.
    Keywords: ASTROPHYSICS
    Type: Space Iconics (NASA-TT-F-798); p 121-135
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2011-08-16
    Description: Several methods using an approximate form of the scattering indicatrix are discussed for simplifying the calculation of radiation transport in planetary atmospheres.
    Keywords: ASTROPHYSICS
    Type: Space Iconics (NASA-TT-F-798); p 75-84
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2011-08-16
    Description: Electrographic imagery of Comet Kohoutek in the 1100-1500 A wavelength range was obtained from a sounding rocket on Jan. 8, 1974, and from the Skylab space station on 13 occasions between Nov. 26, 1973 and Feb. 2, 1974. These images are predominantly due to Lyman-alpha (1216 A) emission from the hydrogen coma of the comet. The rocket pictures have been calibrated for absolute sensitivity and a hydrogen production rate has been determined. However, the Skylab camera suffered degradation of its sensitivity during the mission, and its absolute sensitivity for each observation can only be estimated by comparison of the comet images with those taken by the rocket camera, with imagery of the geocoronal Lyman-alpha glow, of the moon in reflected Lyman-alpha, and of ultraviolet-bright stars. The rocket and geocoronal comparisons are used to derive a preliminary, qualitative history of the development of the cometary hydrogen coma and the associated hydrogen production rate.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2011-08-16
    Description: The appearance of a 'sunward' spike, opposite in apparent orientation to the normal Type-II tail in Comet Kohoutek is interpreted as evidence for large particles ejected near perihelion. It is shown that the shape and orientation can be satisfactorily explained in this manner, after consideration of the increased mass flow at decreasing heliocentric distance. The apparent length of the spike can be a measure of the particle size and density, and a value of about 0.004 g/sq cm for the product of particle size and density fits the Skylab observations.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: It is pointed out that excited states of He-4 cannot produce gamma ray line emission of astrophysical significance, contrary to a recent suggestion of Reina et al. (1974). The only possible gamma-ray lines in He-4 are above 25 MeV, but their excitation cross sections appear to be so small that they are probably of little astrophysical significance.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 36; 2, No; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2011-08-16
    Description: A systematic study is made of the number and types of solutions of the equilibrium equations of stellar structure, in the case of homogeneous stars of Population I over the mass range 2-1000 solar masses, with four different opacity representations. A variant of the usual fitting method permits the simultaneous investigation of convergence and tendency toward multiplicity of the solutions. Quadratic interpolation and extrapolation of Carson's new opacity tables produces a very large opacity at low temperatures that greatly affects the loose outer layers of massive stars, while leaving the cores practically unaffected. As a result, over a small mass range, well above 100 solar masses, triple solutions exist, always near an effective temperature of log Te = 4.73. A simple classification of the known exceptions to the Vogt-Russell theorem on the uniqueness of stellar structure is given.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2011-08-16
    Description: Neutrino pair emission from stellar interiors is investigated. The paper indicates that the proposed enhanced emission mode is a part of a transverse mode spectrum with a refraction index in the limit of infinity. It is concluded that in an astrophysical sense a very strong magnetic field does not have a significant effect on the emission rate of neutrinos from plasmons.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 31; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Publication Date: 2011-08-16
    Keywords: ASTROPHYSICS
    Type: Nature; 252; Dec
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Publication Date: 2011-08-16
    Description: A spectrometer was used on the satellite Copernicus to observe a chromospheric L alpha emission from the K0 giant beta Gem at 1218.4 A. This emission appears to be in the corona at temperatures near 260,000 deg K, since the ion it is identified with requires 77.4 eV to be produced.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Publication Date: 2011-08-16
    Description: On the basis of a consideration of the rotation constant and the hyperfine structure together with the results of an ab initio structural calculation it is suggested that the three closely space new interstellar lines near 93.174 GHz reported by Turner (1974) might have been produced by the molecular ion N2H(+). It is pointed out that the identification of N2H(+) is reasonable also in terms of current ideas of interstellar chemistry.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Oct. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: A series of active cavity radiometers (ACRs) are described which have been developed as standard detectors for the accurate measurement of irradiance in absolute units. It is noted that the ACR is an electrical substitution calorimeter, is designed for automatic remote operation in any environment, and can make irradiance measurements in the range from low-level IR fluxes up to 30 solar constants with small absolute uncertainty. The instrument operates in a differential mode by chopping the radiant flux to be measured at a slow rate, and irradiance is determined from two electrical power measurements together with the instrumental constant. Results are reported for measurements of the solar constant with two types of ACRs. The more accurate measurement yielded a value of 136.6 plus or minus 0.7 mW/sq cm (1.958 plus or minus 0.010 cal/sq cm per min).
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Publication Date: 2011-08-16
    Description: Observations of nonthermal continuum radio emission at 750 MHz and hydrogen-line emission at 1420 MHz have been compared in order to test the extent to which cosmic-ray electrons, magnetic fields, and hydrogen gas coexist in the interstellar medium. If the interstellar medium is homogeneous in the sense that its constituents are mixed together and can interact, then regions of line and continuum emission should be spatially correlated. The measurements indicate that at most 28% of continuum emission in the Galaxy comes from such a homogeneous medium. The remaining nonthermal emission agrees in magnitude with the residual emission found by Berkhuijsen after subtraction of the polarized component of nonthermal emission. In addition, the data discussed here show that the major filamentary structures found in the two forms of emission rarely coincide spatially. Consequently, both the average and the exceptional structure in the medium indicate that the synchrotron-radiating magnetoplasma and the neutral hydrogen gas are not closely interacting in the present state of the medium.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Publication Date: 2011-08-16
    Description: Consistent data for more than 8 years have been obtained from two identical cosmic dust particle experiments on board the space probes Pioneer 8 and 9. The two spacecraft are in direct heliocentric orbits with perihelia between 0.75 AU and 1.00 AU. On the basis of the data it is concluded that the majority of dust particles having elliptical orbits detected by the two space probes show orbital characteristics of Apollo group asteroids which originated from residual nuclei of short-period comets.
    Keywords: ASTROPHYSICS
    Type: Nature; 252; Dec. 13
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Candidate space missions to study the temperature profiles, and ratios of hydrogen to helium in outer planet atmospheres are discussed in terms of scientific payloads for optical occultation, radio occultation, and thermometer measurements.
    Keywords: ASTROPHYSICS
    Type: Dynatrend, Inc. Proc. of Outer Planet Probe Technol. Workshop, Sect. 1 through 11; 8 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Publication Date: 2016-06-07
    Description: Near infrared ice band measurements, radar and radio observations, and implications of the size estimates of particles in Saturn's rings are discussed. The measurements are compared to the Poynting-Robetson effect and a possible mechanism by which the size of the particles may significantly change after the initial formulation of the material in the rings is proposed.
    Keywords: ASTROPHYSICS
    Type: The Rings of Saturn; p 107-123
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Outgassing of H and OH from Saturn's rings and the possibility of detecting it are examined. The source gas around the rings is computed after which the products of ice, H2O, H, and OH and the physical mechanisms that produce these species are given. Production rates for the ice products are discussed.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 125-129
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Publication Date: 2016-06-07
    Description: A 64m radar antenna was used to observe Saturn's rings at 12.6 cm wavelength, with reduced Doppler spread. The results show a positive radar return corresponding to about a 60 percent return from an isotropic scatterer with the projected area of the rings, allowing for the Cassini division. A radar spectrogram of the rings is shown with power density plotted against Doppler frequency shift.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 73-82
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2016-06-07
    Description: After adjusting for the decreased Sun-Saturn distance and adjusting all measurements to B ring values only, it is shown that the temperature variations are not as large as was thought. Various models of the multilayer agglomerate of particles of Saturn's rings are evaluated. It is recommended that the difference between the 11 and 20 micron brightness temperatures should be explained by a satisfactory model.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 65-72
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Spacecraft design is discussed for probing Saturn's rings. Ring particles are also considered, emphasizing material outside of ring A and the hazard this might imply to a spacecraft crossing the ring plane beyond ring A.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 29-38
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2016-06-07
    Description: The probable chemistry of the Saturn rings is reviewed. Reflectance spectra for H20 and NH3 frosts and Saturn's rings are compared, along with temperature dependence of 1.6 microns water frost feature. The reflection spectra of Galilean satellite J2 and water frost are also reviewed.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 51-63
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2016-06-07
    Description: The effects of multiple anisotropic scattering were calculated, including the solar penumbra effect for shadowing computations. The classical model was matched to observations, including the wavelength dependence, by varying the particle albedo as a function of wavelength. A scattering diagram is also presented showing the relative amount of primary and higher-order scattering necessary to match the B ring brightness and the shape of the phase curve.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 17-28
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2016-06-07
    Description: The photometric phase curves of Saturn's rings are considered, as well as a conflict between dynamical and photometric models of the rings. The dependence of ring brightness on angular separation of the earth and sun as viewed from Saturn is discussed. The nonlinear brightness surge is interpreted. Some quantitative calculations were carried out for bodies in and near the asteroidal belt. Predicted density profiles of the ring obtained with Mimas in an eccentric orbit and in a circular orbit are also included.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington The Rings of Saturn; p 3-15
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Keywords: ASTROPHYSICS
    Type: JPL Proc. of the Intern. Colloq. on Drops and Bubbles, Vol. 1; p 11-34
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Keywords: ASTROPHYSICS
    Type: JPL Proc. of the Intern. Colloq. on Drops and Bubbles, Vol. 1; p 1-10
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 36; 3, De; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: Stellar winds from a binary star will interact with each other along a contact discontinuity. We discuss qualitatively the geometry of the flow and field resulting from this interaction in the simplest case where the stars and winds are identical. We consider the shape of the critical surface (defined as the surface where the flow speed is equal to the sound speed) as a function of stellar separation and the role of shock waves in the flow field. The effect of stellar spin and magnetic sectors on the field configuration is given. The relative roles of mass loss and magnetic torque in the evolution of orbital parameters are discussed.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 31; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 2019-06-27
    Description: 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.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2019-06-27
    Description: 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.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Publication Date: 2019-06-27
    Description: The model derived for the anti-tail of Comet Kohoutek describes it as a flat formation, confined essentially to the comet's orbit plane and composed of relatively heavy particles (mostly in the size range 0.1-1 mm) whose motions are controlled by solar gravity and solar radiation pressure. Almost all the material was produced by the comet before perihelion at a rate about an order of magnitude higher than for Comets Arend-Roland and Bennett. The latent heat of vaporization of the particle material is estimated at 40-45 kcal/mole or higher.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2019-06-27
    Description: An upper limit on the rate of evolution of CO from Comet Kohoutek has been obtained from a search for resonant scattering of sunlight near 4.7 microns. The observations were made approximately two months after perihelion. The rate of evolution of CO at that time was apparently less than that of CH3CN observed before perihelion.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: With two f-values of C I lines obtained from the spectra of zeta Pup and gamma(2) Vel, it is shown that the interstellar C I spectrum in zeta Oph obeys an optical-depth relation similar to that for Na I, and the relative strengths of 19 multiplets are determined from this relation. The dominant processes which excite neutral carbon are used to calculate populations of the fine-structure levels as functions of the density of H nuclei and the temperature, and evidence is found that the C I lines are formed in the dense cloud in front of zeta Oph at a heliocentric velocity of -14.4 km/s. It is noted that the observed column-density ratios of the neutral carbon fine-structure levels lead to a total H nuclei density of about 220 to 660 per cu cm, while the electron density and observed C(+) abundance indicate a value of 10,000 per cu cm, with a 0.05 pc thick gas layer.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 37; 2, De; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 2019-06-27
    Description: Consideration of the evolution of thermonuclear runaways in the hydrogen-rich envelopes of 0.5 solar mass carbon-oxygen white dwarfs. The larger radii of these stars, compared with the 1.00 solar mass white dwarfs, results in a lesser degree of degeneracy at the same depth in the star. Four models of luminosity with .00355 solar luminosity, differing only in the initial abundances of C-12, N-14, and O-16, are presented. The degree of enhancement required to produce mass ejection, and thereby a nova-type outburst, is greater than for the 1.00 solar mass model. Nevertheless, the evolution of the 0.5 solar mass model that ejected material is very similar to that of the 1.00 solar mass models, and it also ejects significant amounts of C-13, N-15, and O-17 into the interstellar medium. The 0.5 solar mass outburst is considerably less intense than the 1.00 solar mass outburst (even under optimum conditions), and this lower mass behavior is interpreted as associated with the observed outburst of the slowest novae.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 192; Sept. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2019-06-27
    Description: The spectral energy distribution of Sirius between 2500 and 3700 A at a resolution of 7 A is obtained from plates taken on Gemini 12. The agreement with other observations and the most recent line-blanketed model atmospheres is good. The equivalent width of the Mg II doublet near 2800 A is 6.0 A, if the continuum level is represented by regions near 2650 and 2910 A. This is consistent with expectations for a hot Am star and implies line blocking of up to 15% in this wavelength region.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 192; Sept. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: Analytic expressions describing the infrared radiation and hydrogen to helium line intensity ratios from a dusty nebula are presented. Implications of these results are discussed briefly.
    Keywords: ASTROPHYSICS
    Type: ESRO H2 Regions and the Galactic Centre; p 173-178
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: The effects of dust inside H2 regions were studied by means of theoretical models of dusty nebulae. Infrared observations were analyzed and clear evidence was found that the emitting dust is mostly mixed with the ionized gas. Some information about the amount, distribution, and properties of dust grains was also derived.
    Keywords: ASTROPHYSICS
    Type: ESRO H2 Regions and the Galactic Centre; p 163-171
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 2019-06-27
    Description: A bimodal model of interstellar grains consisting of silicate cores of size approximately 0.06 micron with modified ice mantles of approximately 0.1 micron and very small particles of silicate and/or graphite of size approximately 0.005 micron is followed through various stages of evolution. Starting with a distribution of core-mantle cylinders producing average wavelength dependence of polarization and extinction, changes in physical and optical characteristics of the model are studied going first into regions of dense cloud condensation and coming out at the other end of star formation into young H2 regions. Physical justification is presented to show that not only in dense clouds must the core mantle grains be larger than normal, but also in young H2 regions.
    Keywords: ASTROPHYSICS
    Type: ESRO H2 Regions and the Galactic Centre; p 153-162
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Publication Date: 2019-06-27
    Description: The expected polarization of far infrared sources is discussed, and it is shown that the observed degree of polarization generally depends on two factors: (1) the availability of a mechanism that can produce polarization, and (2) the gain in polarization which absorption or stimulated emission can produce within a source. It is pointed out that stimulated emission could produce sizeable gain changes in compact dust clouds such as those associated with H2 regions and possibly also in dense regions exhibiting OH and H2O masers. Whether such a gain can actually become positive (maser-like behavior) is not clear, but this would in any case depend on the chemical structure of the grain material and the spectral range of interest.
    Keywords: ASTROPHYSICS
    Type: ESRO H2 Regions and the Galactic Centre; p 179-184
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-06-27
    Description: Protons with energies ranging from about 500 eV to 3,500 eV were observed by the Suprathermal Ion Detector Experiment (SIDE) on both the dusk and dawn sides of the magnetosphere. On each lunation these particles appeared as a rather continuous phenomenon for 3 to 5 days after crossing from the dawn-side magnetosheath into the solar wind and for about 2 days prior to entering the dusk-side magnetosheath. Data from the SIDE and from the Explorer 35 lunar orbiting magnetometer were analyzed and these data indicated that the transverse ion flows observed by the SIDE in the pre and post bow shock crossing regions of the lunar orbit are due to these deviated solar wind particles. A computer model based on drift trajectories for particles leaving the shock was developed and synthetic particle data produced by this model are in good agreement with the observed data.
    Keywords: ASTROPHYSICS
    Type: NASA-CR-147653
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2019-06-27
    Description: The post-Newtonian limit of Rosen's theory of gravity is evaluated and is shown to be identical to that of general relativity, except for the PPN parameter alpha sub 2, which is related to the difference in propagation speeds for gravitational and electromagnetic waves. Both the value of alpha sub 2 and the value of the Newtonian gravitational constant depend on the present cosmological structure of the Universe. If the cosmological structure has a specific but presumably special form, the Newtonian gravitational constant assumes its current value, alpha sub 2 is zero, the post-Newtonian limit of Rosen's theory is identical to that of general relativity--and standard solar system experiments cannot distinguish between the two theories.
    Keywords: ASTROPHYSICS
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Publication Date: 2019-06-27
    Description: Pioneer 9's magnetic field and plasma data were studied to develop arguments for or against the observation of oblique interplanetary shocks. Structural classifications are defined, and the justification for seeking these classifications in the solar wind are presented.
    Keywords: ASTROPHYSICS
    Type: NASA-CR-147207 , TRW-24034-6001-RU-00
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Publication Date: 2019-06-27
    Description: The scalar, electromagnetic, and gravitational geodesic-synchrotron-radiation (GSR) spectra are determined for the case of a test particle moving on a highly relativistic circular orbit about a rotating (Kerr) black hole. It is found that the spectral shape depends only weakly on the value of the angular-momentum parameter (a/M) of the black hole, but the total radiated power drops unexpectedly for a value of at least 0.95 and vanishes as the value approaches unity. A spin-dependent factor (involving the inner product of the polarization of a radiated quantum with the source) is isolated to explain the dependence of the spectral shape on the spin of the radiated field. Although the scalar wave equation is solved by separation of variables, this procedure is avoided for the vector and tensor cases by postulating a sum-over-states expansion for the Green's function similar to that found to hold in the scalar case. The terms in this sum, significant for GSR, can then be evaluated in the geometric-optics approximation without requiring the use of vector or tensor spherical harmonics.
    Keywords: ASTROPHYSICS
    Type: Physical Review D - Particles and Fields; vol. 10
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Res. in the Space Sci., vol. 1, no. 3,; 10 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics; 37; 2, De; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2019-06-27
    Description: Some new data pertinent to forbidden transitions for coronal lines of S XII, Ca XIII, K XI, Mn XIII, Fe XIV, Co XV, Ni XVI, N XV, Cr IX, Fe X, and Ni XII are presented. We include additional calculations of collision strengths for a number of ions and then set up and solve the equations of statistical equilibrium in the limiting approximations in which contributions to level population by cascade from higher levels are neglected. We then calculate volume emissivities per ion as a function of density and temperature.
    Keywords: ASTROPHYSICS
    Type: vol. 28; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: 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.
    Keywords: ASTROPHYSICS
    Type: Icarus; 23; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Publication Date: 2019-06-27
    Description: It has been suggested by Cameron (1973) that a cloud of comets containing a mass of condensable elements, comparable to the mass of such elements in the sun, formed on the outskirts of the solar system. If the formation of such comet clouds is a general feature of star formation, they constitute a significant sink of elements heavier than helium. It is shown here that this process provides a possible explanation for the very slow rate at which the mean metal abundance of disk stars has increased during the lifetime of the Galaxy.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 31; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Publication Date: 2019-06-27
    Description: Mathematical procedures are developed which can provide an exact solution for the structure of synchronously rotating close binaries built on the polytropic model with nu equal to 3. Results are discussed for separations of centers of 10.0, 4.0, 3.0, and 2.8 solar radii. For the present discussion, both components are assumed to have the solar mass and, in the zeroth approximation, the solar radius. The present results are compared with those obtained by Chandrasekhar (1933) using first-order perturbation theory.
    Keywords: ASTROPHYSICS
    Type: vol. 28; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Publication Date: 2019-06-27
    Description: Equivalent widths of some 50 lines in the 0-0 to 5-0 Lyman bands of H2 are reported in the spectra of 28 stars. Curves of growth are given and column densities for levels from J = 0 to J = 5 are tabulated, with a few values and upper limits for N(6) and N(7), together with values for b, the velocity spread parameter. In three Orion stars and in rho Leo pairs of components are detected, the difference in radial velocity is determined, and column densities are measured or estimated; tentative identifications are made with the components observed by Hobbs (1969) in the Na D-lines. Column densities for HD are given for 13 stars. Upper limits for column densities in the first and second vibrational levels are listed for several stars; the ratio of N(J = 0) in the v double prime = 1 level to that in the ground vibrational level is less than 2.4 x 10 to the minus 8th power in zeta Oph. Values of a rotational excitation temperature for the higher J levels are given for all the stars. Data are presented which show an apparent increase of velocity dispersion with J for a number of stars, as measured both from the curves of growth and from line widths.
    Keywords: ASTROPHYSICS
    Type: vol. 28; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2019-06-27
    Description: The intrinsic phase-dependent linear polarization of two magnetic Ap stars is studied. The polarization characteristics in a broad blue filter band and in the ultraviolet are outlined, and the mechanisms of polarization are examined. The blue band polarization of 53 Cam (corrected by removing the stellar component) is found to be compatible with an oblique rotator whose angular parameters are in essential agreement with those deduced by Landstreet (1970) and by Huchra (1972).
    Keywords: ASTROPHYSICS
    Type: Royal Astronomical Society; vol. 166
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Publication Date: 2019-06-27
    Description: 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.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Publication Date: 2019-06-27
    Description: The Cygnus Loop was observed with a one-dimensional X-ray telescope. Data from two orthogonal scans showed no evidence for a pointlike remnant of the supernova at the center of the Loop. We set an upper limit to the presence of such a source of 2.9% (at 99.9% confidence) of the total emission in the bandwidth from 400 eV to 850 eV. The pulsed component at 62.31 msec suggested by Rappaport et al. (1973) was not observed.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: The object is anomalous, and the existing data appear to be rather contradictory or ambiguous. We discuss previous and new observations. The new observations are: Palomar Schmidt plates in the blue, yellow, red, and near-infrared; radiofrequency-continuum maps at 7.875 and 15.5 GHz; flux densities at 31.4 and 85 GHz; and H 94 alpha-line data. A nebula, found only in the red, is identifiable with a small component of a supernova remnant which is altogether about 1 deg in diameter. The spectral index of the large, nonthermal remnant is prevalently about -0.8, but the index is probably not less than -0.5 in the small component. The amorphous structure of the red nebula suggests that its light is nonthermal, since it is not a reflection nebula of the star gamma Cygni.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Publication Date: 2019-06-27
    Description: Study illustrating how the presence of a high-intensity pulse of radiation can distort its own passage through a plane differentially shearing medium. It is demonstrated that the distortion is a sensitive function of the precise, and detailed, variation of the medium's refractive index by considering a couple of simple examples which are worked out numerically. In view of the high-intensity pulses observed from pulsars (approximately 10 to the 30th ergs per pulse), it is believed that the present calculations are of more than academic interest in helping unravel the fundamental properties of pulse production in, and propagating through, differentially sheared media - such as pulsars' magnetospheres within the so-called speed-of-light circle.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2019-06-27
    Description: An X-ray surface brightness map of the Cygnus Loop in the energy range 0.15-0.85 keV is presented. The X-ray distribution is compared with the optical and radio pictures of the Loop. The location of the center of the supernova shell as derived from the X-ray data is in excellent agreement with the apparent optical and radio centers. We obtain a mean diameter for the X-ray shell of 2.75 (+ or - 0.2) deg. The X-ray spectral data yield a characteristic thermal temperature averaged over the Loop of 2.9 million (+ or - 1.5 million) K. We have calculated anew X-ray parameters for adiabatic blast waves using X-ray production spectra which include line radiation. These parameters are compared with the results of the present experiment. An age of 18,000 years, initial blast energy equal to 3 times 10 to the 50-th power ergs, and ambient interstellar density of 0.25 per cu cm are found.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2019-06-27
    Description: Data are presented which show that the strengths of the diffuse interstellar bands at 4430, 5780, and 5797 A tend to be deficient with respect to color excess in the lines of sight to stars lying behind dense interstellar clouds. In addition, diffuse-band data for ten stars in the well-studied rho Ophiuchi cloud complex are presented, and systematic variations of band strengths with optical depth are discussed. It is found that the band strength per grain in the line of sight apparently decreases with increasing grain size, taking the ratio of total-to-selective absorption and the wavelength of maximum polarization as indicators of the latter. It is concluded that diffuse-band formation probably takes place most efficiently in the outer regions of interstellar clouds. This may be consistent with a diffuse-band origin in small grains which are coated by mantles in cloud interiors; or in some molecule or molecules which are most abundant in the outer portions of interstellar clouds.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: The nucleus of M31 was photographed at a resolution of 0.2 sec with the 91-cm balloon-borne Stratoscope II telescope. At the half-intensity level, the nucleus was observed to be elliptical with its major axis lying in position angle of 63 (plus or minus 5) deg. The peak surface brightness was 12.7 plus or minus 0.3 V mag per square second of arc assuming B - V = 1.0. The nucleus appears to be a separate feature from the bulge with a scale height of approximately 0.5 pc. The mass of the nucleus is of the order of 100 million solar masses, and the apparent visual mass-to-light ratio is of the order of 20.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Geophysical Research Letters; 1; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Publication Date: 2019-06-27
    Description: Plasma and field data from Mariner 4 and 5 between 0.7 and 1.6 AU are used to study the radial dependence of the levels of microscale fluctuation associated with interplanetary Alfven waves. The observed decrease of these levels with increasing distance from the sun is consistent with little or no local generation or damping of the ambient Alfven waves over this range of radial distance.
    Keywords: ASTROPHYSICS
    Type: Journal of Geophysical Research; 79; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: This review is meant for the nonspecialist who wants a simple physical picture. Some simple calculations are given to show why waves and irregularities in the solar wind are of importance in obtaining a physical understanding of the dynamical processes occurring in the interplanetary medium. The basic physics of various phenomena observed in the heliosphere, resulting because of the presence of waves in the solar wind, is spelled out in some detail. The most fundamental point made in this review is that a considerable body of phenomena occurring in the solar wind are either caused directly or modified significantly by the turbulent waves that are always present in the solar wind.
    Keywords: ASTROPHYSICS
    Type: Reviews of Geophysics and Space Physics; 12; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Publication Date: 2019-06-27
    Description: Utilizing a four-antenna technique, simultaneous observations were made, at each end of an 845-km baseline, of the radio sources 3C279 and 3C273B, which are 10 deg apart in the sky. Differences in interferometric phases at 3.7-cm wavelength monitored near the time of the 1972 occultation of 3C279 by the sun, yielded a gravitational deflection of 0.99 plus or minus 0.03 times the value predicted by general relativity, corresponding to gamma = 0.98 plus or minus 0.06 (standard error).
    Keywords: ASTROPHYSICS
    Type: Physical Review Letters; 33; Dec. 30
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Publication Date: 2019-06-27
    Description: We present new molecular constants, line positions, and transition probabilities for the first-overtone vibration-rotation bands in the X 1 Sigma+ electronic ground state of SiO, together with an estimate of the SiO abundance and silicon isotope ratios in the atmosphere of alpha Ori.
    Keywords: ASTROPHYSICS
    Type: Astronomical Society of the Pacific; vol. 86
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Publication Date: 2019-06-27
    Description: Photoelectric spectral scans at 30 A resolution of nine dwarfs, ten giants, and six supergiants with spectral types G0 to M5 are presented. (All stars were observed every 4 A from 3300 to 7000 A.) Absorption features observed at this resolution coincide with: strong atomic lines of Fe I, Fe II, Ca I, Ca II, Mg I, and Na I; vibrational bands of the electronic transitions of TiO, MgH, CaH, SiH, AlH, CN, CH, C2, OH, and NH. The dependences of the 3740-A Fe I blend and the 3440-A depression on temperature are discussed.
    Keywords: ASTROPHYSICS
    Type: Astronomical Society of the Pacific; vol. 86
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Publication Date: 2019-06-27
    Description: The spectrum of the white dwarf suspect, GD 90, is shown to contain broad Balmer lines with resolved Zeeman structure. All the observed features correspond to the calculated spectrum of hydrogen at 5 plus or minus 0.5 MG. A region of approximately 20% of the observed stellar disk must be subject to a reasonably uniform field of this strength. The sigma components of the Zeeman patterns in H beta and H gamma are found to be circularly polarized, indicating that the field has a component directed along the line of sight. There is evidence for an additional stronger and less homogeneous field, as would be expected if the dominant 5 -MG region were at the equator of a dipolar field.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Nov. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Publication Date: 2019-06-27
    Description: Recent Monte Carlo computations, based on a speculative extrapolation of the electron spectrum, suggested that repeated scatterings contribute most of the extragalactic X-ray background around 3 MeV in a Compton model. We have redone this calculation analytically with a similar electron spectrum, but with very different results. The double-scatter contribution near 3 MeV does not exceed 1 percent and cannot improve the fit to data. The effect is largest near 1 keV but will probably not be observable.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 194; Nov. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Publication Date: 2019-06-27
    Description: Attention is given to a moderate-resolution spectra of the Orion Nebula. Observational data are presented between 20 and 40 microns. Several models are shown that attempt to account for all of the observations from 20 microns to 1 mm. A model in which the dust within the molecular cloud has a clumpy distribution is given. Data show that the individual clumps have effective grain temperatures of 100 deg K and they are optically thick for wavelengths shorter than 400 microns.-
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Publication Date: 2019-06-27
    Description: Two rocket observations of very soft X-ray diffuse intensity show three emission regions of large angular extent. A large portion of the sky as seen with wide angular resolution is mapped. These three regions coincide with broad regions of small column densities of neutral hydrogen. It is suggested that a component of the interstellar medium is very hot and is responsible for the soft X-ray emission and the O VI.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: Based on high-resolution observations using the Princeton satellite/spectrometer on Copernicus the O VI doublet is discussed in detail, in conjunction with data for the resonance lines of N V, Si IV, and S IV reported in five stars. The temperature, density, and the possible extent of the O VI producing region are discussed. The ratio N(S IV)/N(O VI) is used to derive a lower limit to the temperature in the O VI producing region. In near pressure equilibrium with normal interstellar clouds and H II regions minimum densities are found to be consistent with a hot plasma.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Publication Date: 2019-06-27
    Description: The presence of broad, shallow absorptions caused by O VI ions were revealed from UV spectra observations recorded by the Copernicus satellite for thirty-two stars. A table lists survey data on the stars observed for which values of the O VI column densities or their upper limits are extracted. Interstellar rather than circumstellar origin is evident from observation of the lack of correspondence between radical velocities of the stars and those of the O VI profiles. The presence of a low-density high-temperature phase of interstellar gas produced by supernova explosions is suggested.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Publication Date: 2019-06-27
    Description: The isotopic abundance ratio C-12/C-13 for the M supergiant alpha Orionis is derived from photoelectric high-resolution scans of the CN 2-0 red system and high-resolution interferometric spectra of the CO second-overtone bands. The two molecules yield consistent results and the final value for the C-12/C-13 ratio is 7.0 plus or minus 1.5. Rationale is offered for the causes contributing to an earlier suggestion that C-12/C-13 ratios from CO and CN were in disagreement.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 193; Nov. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-27
    Description: Observational data are presented that suggest both the existence of extensive halo slabs of ionized gas and the probable presence of a hot corona around our galaxy. Evidence shows that when considering the galactic plane this ionized or neutral gas has a more extended distribution than the HI component. The characteristics of the halo gas consist of the ability (1) to interpenetrate, (2) to be heated, and (3) to be in a pressure equilibrium with the intercloud component of the local interstellar medium.
    Keywords: ASTROPHYSICS
    Type: Comments on Modern Physics; vol. 6
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Publication Date: 2019-06-27
    Description: Results of a computation of a variety of evolutionary sequences involving thermonuclear runaways in the hydrogen-rich envelopes of 1.00-solar-mass carbon-oxygen white dwarfs. The evidence concerning the location of the outburst in the nova system is reexamined, and it is concluded that the white dwarf is the seat of the outburst. An order-of-magnitude argument is presented which indicates that for a 1.00-solar-mass white dwarf it is impossible to achieve mass ejection without an energy generation of approximately 10 to the 16th ergs/g/sec. A description is given of models with low nuclear enhancements that do not produce an outburst, although their evolution has certain implications for the cause of the dwarf-nova outburst. The results for models that produced a nova outburst are then presented, and on the basis of these results it is found possible to explain continuous ejection, Kukarkin and Parenago's (1934) relationship, and other gross features of the nova phenomena.
    Keywords: ASTROPHYSICS
    Type: vol. 28; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Publication Date: 2019-06-27
    Description: The results from the Celescope Catalog of Ultraviolet Stellar Observations (Davis, Deutschman, and Haramundanis 1973) are studied, emphasizing statistical groups and subgroups of stars. In spite of the rather large observational errors, the great number of Celescope observations make it possible to do that kind of study with reasonable accuracy. Some stars have ultraviolet colors that differ significantly from those of the group to which they have been assigned on the basis of ground-based observations. An attempt is made to describe the general properties of the ultraviolet colors of the stars as observed by the Celescope experiment on board NASA's Orbiting Astronomical Observatory (OAO-2). Besides the direct applicability of these results to the general study of stellar atmospheres and of interstellar extinction, they are also considered as a frame of reference for further studies of individual stars and groups of stars.
    Keywords: ASTROPHYSICS
    Type: vol. 28; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...