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IUE Observations of the Interstellar Medium toward beta Geminorum
Moos, H. W.; Murthy, J.; Linsky, J. L. +4 more
A dispersion IUE spectrum of the hydrogen Ly-alpha emission line of the nearby late-type star Beta Gem is presented. Values are determined for the density, velocity, dispersion, and bulk velocity of the interstellar H I toward the star, showing agreement with previous IUE results for stars in the same general direction (Murthy et al., 1987). It is…
Analysis of the Velocity Law in the Wind of the Be Star lambda Pavonis
Sahade, Jorge; Kondo, Yoji; Chen, Haiqi +1 more
This paper reanalyzes the IUE spectra of Lambda Pavonis secured in 1982 (Sahade et al.). It is found that the profiles of the broad UV lines are either rotationally broadened or nonrotationally broadened and that the rotationally broadened profiles can be sorted out in two groups characterized by rotational velocity values of 170 km/s and of 210 k…
The Temperatures of White Dwarfs in Accreting Binaries
Szkody, Paula; Sion, Edward M.
Long-term observations of the dwarf nova WZ Sge with an outburst recurrence time of 33 years are studied. The results indicate that the UV flux reached an equilibrium value at about the end of 1986; this means that the UV flux continued to decrease for 8 years after outburst. If the underlying dwarf has provided a dominant amount of the UV flux si…
Galactic Interstellar Abundance Surveys with IUE. III. Silicon, Manganese, Iron, Sulfur, and Zinc: Erratum
Shull, J. Michael; van Steenberg, Michael E.
Sanduleak's Star (LMC Anonymous): Its Similarity in the Far-Ultraviolet with the Luminous Object eta Carinae and SN 1987A
Kafatos, M.; Michalitsianos, A. G.; Shore, S. N.
Spectra obtained in the far UV wavelength range 1200-2000 A with the International Ultraviolet Explorer (IUE) of the peculiar emission object LMC Anonymous, or Sanduleak's Star in the Large Magellanic Cloud, indicate the presence of circumstellar-high-excitation gas, which is rich in CNO processed material. Although LMC Anonymous is a field star w…
The ultra-violet spectrum of the peculiar early-type supergiant, HD 157038.
Dufton, P. L.; Lennon, D. J.
Ultra-violet spectra of the nitrogen rich supergiant, HD 157038, are presented and compared with those of the normal supergiant, HD 148379. The P-Cygni profiles of the Si IV and C IV resonance lines are very similar, implying that the stars have similar masses; this is evidence against HD 157038 being in a post red supergiant evolutionary stage an…
Population Synthesis in Starburst Galaxies - MARKARIAN:710
Mas-Hesse, J. M.; Kunth, D.; Arnault, P.
Evolutionary population synthesis models have been built to study the properties of the starforming processes taking place in starburst regions. BothZ⊙ andZ⊙/10 stellar evolutionary tracks have been used to take into account that starburst galaxies are generally metal deficient. A very small time step allows us to follow the …
Experimental plasma parameters at comet Halley
Amata, E.; Formisano, V.; Wilken, B. +3 more
Bulk speed, density and temperature of the plasma are computed for protons and water-group ions in comet P/Halley using data from the two ion sensors of the JPA experiment flown on Giotto. Two water group ion populations, locally generated and implanted further upstream, evolve with different density and temperature during the fly-by. The centre o…
A Simple Population Synthesis Model for the Continuum of the SEYFERT-2 Galaxy MARKARIAN:348
Terlevich, Roberto; Terlevich, Elena; Diaz, Angeles I. +1 more
The spectral energy distribution of the Seyfert type-2 galaxy Mk 348 is analyzed based on IUE observations and published data. It is found that most of the optical and near-IR flux comes from the underlying galaxy bulge population. The rest of the emission can be fitted by a power law of the formFv ∼v‑α with α=0.6. In order t…
Systematic Errors in Spectral Features Introduced by Random Noise
Joseph, Charles L.
A common IUE computer routine for measuring equivalent widths is shown to introduce systematic errors in data containing large amounts of noise. During statistical tests using simulations of synthetic spectral features with noise characteristics similar to those of the IUE, the routine was found to overestimate the true strength of an absorption l…