• Radiative Acceleration of Material

      Weymann, R. J.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1973)
    • Rapid Evolution of Galactic Nuclei : Proceedings of the 44th IAU Symposium

      Tifft, W. G.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1970-08)
    • Redshift Magnitude Bands and Quasi Stellar Absorption Line Multiple Redshifts

      Tifft, W. G.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1972)
      Quasi stellar absorption line redshifts are shown to be consistent with the redshift- magnitude band pattern concept. The redshifts in multiple redshift objects tend to concentrate at band crossings corresponding to the magnitude of each object.
    • Redshift Quantization in the Lyman-alpha Forest and the Measurement of qo

      Cocke, W. J.; Tifft, W. G.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1988-12)
      We present evidence for redshift quantization in the Lyman -a forest of several QSOs. The Ly -a data are at redshifts z from 1.89 to 3.74, and the theory of redshift quantization proposed by Cocke (1983, 1085) is used to scale the quantization interval (24.15 km s -') to these high redshift. The sealing depends on the deceleration parameter qo, and the quantization is present at a statistical significance of greater than 99% for qo = 1/2. This may be taken as confirming the inflationary model of the early history of the universe. The significance of the quantization is highest at go rs 0.48, and the width of the peak is about 0.03 . The result can also be seen as providing confirmatory evidence for both the theory of the redshift quantization and the above value of qo, but at a significance of only 03 %. The scenario proposed for the relativistic generalization of the theory is that of fermion wavefunctione and quantum operators in a background Riemannian spacetime satisfying Einstein's field equations.
    • Redshift-Magnitude Bands, Quasi Stellar Sources, and Systems of Redshift

      Tifft, W. G.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1972-08)
      The visibility and character of redshift- magnitude bands in a diagram of general field galaxies compared to specific clusters depends upon the cosmological model. In the normal expanding universe model where galaxies have lives comparable to the age of the universe, no band structure should be visible outside of clusters. Band structure is, however, shown to exist among quasi stellar sources and to show the identical slope and band spacing characteristics as do the galaxies in the Coma cluster. At least 14 bands can be identified forming a convergent band series among QSS emission line objects. The validity of the band phenomenon is tested by power spectrum analysis and shown to be highly significant. The distribution of points about the band structure is Gaussian. Cross projections of the band system are shown to give rise to harmonic periodicities which can explain some or all of the periodicities observed in the z distribution of QSS objects. The Coma galaxy band system is shown to be a scaled version of the QSS band system. Galaxies appear to occupy a separate band system which is convergent to the start of the QSS system as its series limit. QSS absorption line objects are further shown to apparently form a third independent band system beginning at the high redshift limit of the QSS emission line system. The band phenomenon is briefly discussed in terms of a model invoking multiple states of matter, rapid galaxy evolution, and possible time evolution of matter observed as a function of lookback time in a singular origin Universe.
    • Search for Close Binary Evolved Stars

      Saffer, R. A.; Liebert, J.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1988-10)
      We report on a search for short -period binary systems composed of pairs of evolved stars. The search is being carried out concurrently with a program to characterize the kinematical properties of two different samples of stars. Each sample has produced one close binary candidate for which further spectroscopic observations are planned. We also recapitulate the discovery of a close detached binary system composed of two cool DA white dwarfs, and we discuss the null results of Ha observations of the suspected white dwarf /brown dwarf system G 29-38.
    • Solid Hydrogen Coated Graphite Particles in the Interstellar Medium, I

      Wickramasinghe, N. C.; Krishna Swamy, K. S.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1968-11)
      Solid hydrogen coated graphite particles may be expelled from regions of star -formation into the general interstellar medium. The solid para- hydrogen mantles, which contain a small proportion of orthomolecules are stable against evaporation in the general interstellar radiation field. They are also stable against physical and chemical sputtering in HI regions. Extinction efficiencies are calculated for solid hydrogen particles and for graphite particles with solid hydrogen mantles. Graphite core -solid hydrogen grains are capable of producing excellent agreement with the interstellar extinction observations from 2u - 1100 A. The graphite core radius may be in the range ro = 0.04 - 0.06u and the solid hydrogen mantle radius in the range r = 0.15 - 0.25u. The albedo and phase function of these particles are consistent with the requirements imposed by the diffuse galactic light. Solid hydrogen is strongly anisotropic in its crystal structure and optical properties. Approximate models yield good agreement with the observed trends of the wavelength dependence of interstellar polarisation.
    • Spectroscopy of Outlying Faint Galaxies Near the Coma Cluster

      Tifft, W. G.; Gregory, S. A.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1972-10)
      Redshifts are reported for twenty -seven outlying galaxies in Coma. Twenty -four have redshifts typical for Coma galaxies. Eleven galaxies show emission lines.
    • SSC 08546+1732: A Faint, Dust-Enshrouded Carbon Star at High Galactic Latitude|A Faint, Dust-Enshrouded Carbon Star at High Galactic Latitude

      Cutri, R. M.; Low, F. J.; Kleinmann, S. G.; Olszewski, E. W.; Willner, S. P.; Campbell, B.; Gillett, F. C.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1988-12)
      During the initial phase of a program to search for sub -stellar candidates at high galactic latitudes in the IRAS Serendipitous Survey Catalog, one source, SSC 08546 +1732, was found to have no optical counterpart on the Palomar Observatory Sky Survey plates. Ground based positional, photometric and spectroscopic observations have identified this source as a heavily dust - enshrouded carbon star, similar to those found in the Galactic plane. The high latitude and relative faintness of this source imply that it lies at a distance of 20 - 50 kpc, and is 10 to 30 kpc out of the plane of the Galaxy. SSC 08546 +1732, along with one other distant obscured carbon star found in the IRAS Point Source Catalog (Low 1987; Beichman e1: al. 1988), represent the first examples of such objects found in the Galactic halo. These stars may either have evolved from population I precursors ejected from the disk, or they may be the first obscured Population II halo carbon stars to be observed. A survey for other distant enshrouded carbon stars in the IRAS Faint Source Catalog should help to elucidate the nature of this new population.
    • Statistical Properties of the Lyman-alpha Forest

      Bechtold, J.; Shectman, S. A.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1988-08)
      We have observed two high -redshift quasars with the echelle spectrograph and 2D- Frutti Photon Counter at Las Campanas, in order to investigate the statistical properties of the Lyman -a forest. The two-point correlation function for the Lyman -a forest lines at z .^s 3 is consistent with zero, for all velocity splittings A > 50 km /sec. When Lyman -a lines and other metal lines from known metalline systems are included, the correlation function shows a weak non -zero signal at small A . We suggest that the weak clustering of the Lyman -a forest detected by other workers may be the result of contamination by a small number of metal -line systems and their associated Lyman -a lines.
    • Stimulated Linear Acceleration Radiation: A Pulsar Radio Emission Mechanism

      Cocke, W. J.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1973)
      The Einstein coefficient method is used to calculate the absorption coefficient K for a steady flux of electrons undergoing acceleration in a uniform electric field. Under the approximation that the motion is ultrarelativistic, the emission frequency is low, and the emission direction is nearly parallel to the direction of motion, we find that K is negative for certain emission directions. The formalism is applied to pulsars, and it is shown that strong maser action is expected. If the emission takes place near the velocity -of -light cylinder, the computed collisional Bremsstrahlung may be strong enough to produce the recently observed high- energy Y -rays.
    • Streaming Motions in the Carina-Centaurus Region

      Humphreys, R. M.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1970-09)
      An analysis of new velocity data for a large number of supergiants confirms results presented earlier that streaming motions of 8 km /sec occur between the sides of the spiral feature in the Carina -Centaurus region.
    • Strip Search for Quasars: The CCD/Transit Instrument (CTI) Quasar Survey

      McGraw, J. T.; Cawson, M. G. M.; Kirkpatrick, J. D.; Haemmerle, V.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1988-09)
    • Structure and Motions in the Carina Spiral Feature

      Humphreys, R. M.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1972)
      The distribution and kinematics of the luminous young stars in the Carina spiral feature (l = 282° - 305 °) are investigated and compared with the available data for the neutral hydrogen gas in the same region. New observational data are presented for 176 luminous stars of all spec- tral types. These stars reveal a well- defined spiral feature from 1.5 to 6 kpc from the sun. It is suggested that both the young stars and hydrogen gas are observed to large distances along the line of sight in Carina. A detailed comparison of the velocities of the stars and dense gas yields a good overall correlation. A noticeable discrepancy at l = 290° between the stellar and gas motions is discussed. Velocity residuals for the stars indicate systematic motions of 6 km /sec between the sides of the spiral feature. These streaming motions should be shared by the associated gas.
    • A Survey of H-Alpha Emission in Early Type High Luminosity Stars

      Rosendhal, J. D.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1973)
    • Symposium on Dark Nebulae, Globules and Protostars

      Bok, B. J.; Cordwell, C. S.; Cromwell, R. H.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1969)
    • Three-Color Photometry of Southern QSOs, Radio Galaxies and Normal Galaxies

      Westerlund, B. E.; Wall, J. V.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1968-12)
      Data on the UBV system are presented for 14 quasistellar radio sources, 8 N galaxies,39 radio galaxies and 19 radioquiet galaxies south of +20° declination. Their positions in the two - color diagram show that the integrated colors of the radio galaxies are similar to those of the radioquiet galaxies of the same morphological type. In an absolute radio magnitude - radio index diagram a linear relation exists between M158 and ím158 Boo for radio galaxies of all classes. The QSO:s, however, do not follow this relation, and possible explanations are considered. The brightness and color distributions in the larger galaxies are described in detail. Our results are combined with other data for a discussion of the compositions of these systems. It is suggested that a fairly high amount of reddening occurs in the central regions of several galaxies, as for instance, in NGC 1068 and NGC 1316.
    • Transfer Effects on X-Ray Lines in Optically Thick Celestial Sources

      Felten, J. E.; Rees, M. J.; Adams, T. F.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1972-05-01)
    • Turbulent Hydrodynamic Line-Stretching: The Random-Walk Limit

      Cocke, W. J.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1970)
    • X-Ray Beaming and Mass Transfer in HZ Her

      Strittmatter, P. A.; Scott, J. S.; Whelan, J. A. J.; Wickramasinghe, D. T.; Univ Arizona, Steward Observ (Steward Observatory, The University of Arizona (Tucson, Arizona), 1973)
      The optical and X -ray properties of HZ Her are analyzed within the framework of a model in which the primary is illuminated by X -ray radiation from a degenerate secondary companion. System parameters are derived on the basis of a simplified model and yield a minimum distance to HZ Her of - 5 kpc. It is shown that the X -ray pulses and 35 day on -off characteristics as well as the shape and modulation of the optical light curve can be understood if (i) the primary is illuminated by X -ray emitted in a beam fixed in a rotating neutron star secondary undergoing forced precession and (ii) energy is supplied by mass transfer from primary to secondary resulting in the formation of a disc around the X -ray source which contributes significantly to the total light.