Search Publications
Ultraviolet spectroscopy with the IUE of OB stars with stellar winds.
Hutchings, J. B.; von Rudloff, I. R.
Spectroscopic observations at high and low resolution (about 2 x 10 to the 4th power, 2 x 10 to the 2nd power) in the 1200-3000 A range are presented for a sample of 21 high-luminosity OB stars. Mass-loss characteristics seen in the strongest line features are examined and discussed. Correlations and comparisons are made with ground-based data and…
IUE observations of circumstellar emission from the late type variable R AQR (M7+pec).
Kafatos, M.; Michalitsianos, A. G.; Hobbs, R. W.
IUE observations of R Aquarii (M7 + pec) have been obtained in low dispersion in order to study its circumstellar emission. Strong permitted, semiforbidden, and forbidden emission lines are identified that are superposed on a bright ultraviolet continuum. From the analysis it is deduced that the strong emission-line spectrum that involves semiforb…
Lyman alpha fluxes of Seyfert galaxies and low-redshift quasars.
Gull, T. R.; Boggess, A.; Wu, C. -C.
The International Ultraviolet Explorer (IUE) was used to measure Ly-alpha fluxes for 13 type 1 Seyferts, one type 2 Seyfert, and one low-redshift quasar. The observed Ly-alpha/H-beta ratio is typically 5 for the type 1 Seyfert galaxies but is 20 for the single type 2 Seyfert. In the Ly-alpha/H-beta versus H-alpha/H-beta diagram, the observations d…
Outer atmospheres of cool stars. VI. Models for EPS ERI based on IUE spectra of C II, MG II, SI II, and SI III.
Linsky, J. L.; Simon, T.; Kelch, W. L.
Observations of the ultraviolet line spectrum of the active chromosphere star, Epsilon Eridani, obtained with the IUE satellite have been analyzed. The coupled statistical equilibrium and radiative transfer equations for the prominent transitions of C II, Mg II, Si II, and Si III. A satisfactory fit to all of the line strengths can be achieved wit…
Ultraviolet, X-ray, and infrared observations of HDE 226868 = Cygnus X-1.
Tanzi, E. G.; Tarenghi, M.; Chiappetti, L. +14 more
During April, May, and July of 1978, HDE 226868, the optical counterpart of Cygnus X-1, was repeatedly observed in the ultraviolet with the IUE satellite. Some X-ray and infrared observations have been made during the same period. The general shape of the spectrum is that expected from a late O supergiant. Strong absorption features are apparent i…
The ultraviolet spectrum of the T Tau star RW Aur.
Giampapa, M. S.; Imhoff, C. L.
Ultraviolet spectra of the T Tauri star RW Aurigae have been obtained with the International Ultraviolet Explorer. Emission lines include Mg II, Fe II, Cr II, Si I, Si II, Si III, Si IV, C II, C IV, and L alpha. The spectrum roughly resembles the solar chromospheric spectrum, but the surface fluxes are 200 times greater. N V and He II appear to be…
Ultraviolet, visible, infrared and X-ray observations of SCO X-1.
Davis, R. J.; Willis, A. J.; Wilson, R. +18 more
The first UV spectroscopic observations of the X-ray source Scorpius X-1, obtained with the IUE satellite, are presented. The UV data consist of low-resolution spectra in the 1150-3200 A wavelength range, and show emission lines arising in Si II and IV; C III and IV; N III, IV, and V; O IV and V, and He II. Also discussed are observations using vi…
Outer atmospheres of cool stars. III. IUE spectra and transition region models for alf CEN A and B.
Linsky, J. L.; Ayres, T. R.
We describe lUE ultraviolet spectra of two nearby dwarf stars, α Centauri A (G2 V) and B (K1 V). These data include high-resolution profiles of the Mg II h and k features and lower- resolution integrated fluxes of lines from the following species: H I, C I-IV, N V, O I, A1 II, Si II-IV, and Fe II. We find that surface fluxes in chromospheric and t…
Spatial imaging of hydrogen Lyman-alpha emission from Jupiter
Feldman, P. D.; Moos, H. W.; Weaver, H. A. +3 more
A sounding rocket measurement of the H I L-alpha emission from Jupiter made on Dec. 1, 1978 shows limb darkening and an average disk brightness of 13 kR. This brightness is significantly higher than in previous measurements, and was confirmed by an IUE observation on Dec. 10, 1978. Comparison with a plane-parallel hydrogen layer model indicates th…
Carbon in Comet Bradfield 1979l
Feldman, P. D.; A'Hearn, M. F.
Ultraviolet spectra of comet Bradfield obtained with IUE show a surprising absence of CO(+) despite the presence of CO2(+), and they also show, for the first time, the unambiguous presence of the Mulliken bands of C2. With the use of simultaneous ground-based data, a value of 0.00001 is derived for the transition moment of the a 3 Pi-X 1 Sigma g +…