Search Publications
Zinc as a tracer of metallicity in the interstellar medium.
Bromage, G. E.; Blades, J. C.; Harris, A. W.
The relative gas-phase abundance of zinc in the interstellar medium has been studied using high-resolution spectra from the IUE data bank of early-type stars with distances of up to 3 kpc. The chosen sight-lines all have measured N(H) values derived from Copernicus observations. Results show that in the H column density range of 5×1019 …
Ultraviolet spectroscopy of LSI +61 303.
Howarth, I. D.
New IUE low-resolution spectroscopy of the X-ray/radio source LSI+61°303 is presented and discussed, and previously reported data critically reassessed. There is no strong evidence for continuum variability; in particular, eight spectra covering the 1200-1950 Å region show a scatter of only ≡3 per cent. There is some variability in the emission li…
Three low-redshift quasars with absorption systems: IUE andoptical observations.
Kunth, D.; Bergeron, J.
The authors have discovered the first two cases of narrow absorption systems with an absorption redshift equal to the emission redshift (Δv ⪉ 500 km s-1) in the low-redshift quasars PKS 1912-54 (zem = 0.401) and PKS 2135-14 (zem = 0.200). They also confirm the existence of a sharp absorption system (zab …
The Seyfert 1 galaxy NGC 4593- II. The pattern of variability of theUV spectrum.
Clavel, J.
IUE observations of NGC 4593 are found to show approximately 30 percent variations in the intensities of the emission lines and UV continuum in nine days, which set upper limits to the dimension of the UV continuum and broad line emitting regions comparable to that found for NGC 4151 and 3783. UV observations at six different epochs show the exist…
Optical and ultraviolet line profiles and ultraviolet line intensities in the T Tauri star LHα 332-21.
Penston, M. V.; Lago, M. T. V. T.
The ultraviolet spectrum of the T Tauri star LHα 332-21 is presented. This shows emission lines of chromospheric origin. Optical and ultraviolet line profiles for this star are compared: in LHα 332-21 the Mg II lines show blue-displaced absorption and outflow is therefore demonstrated. It is argued that the general similarities of the Mg II line p…
The enigmatic composite system HD 45166 - B8V +qWR or SdO ?
Willis, A. J.; Stickland, D. J.
High- and low-resolution IUE ultraviolet spectroscopic observations of the binary system HD 45166, previously classified as qWR + B8 V, obtained at several epochs are presented. The UV spectra show a photospheric absorption spectrum from highly ionized species like Fe v, which with the observation of B8 V absorptions in the visible, confirms the b…
The UV spectrum of the BL Lac object PKS 0521-36.
Maraschi, L.; Tanzi, E. G.; Treves, A. +3 more
Ultraviolet observations (1200-3000 Å) with the IUE satellite of the BL Lac object PKS 0521-36 are presented. The only emission line which appears clearly in the spectrum is Lyα, which is asymmetric with a component displaced ≡3000 km s-1 to the red. The intensity of the line and the upper limits on other lines are compared with the mod…
IUE observations of five DB white dwarfs.
Wickramasinghe, D. T.
IUE spectra of five DB white dwarfs are presented and discussed. The effective temperatures deduced from the UV continua are in good agreement with recent determinations using line data in the optical region. In contrast to the situation with the λ4670 stars, there is no evidence for absorption by atomic carbon lines in the UV.
Ultraviolet and optical observations of two stars belonging to the blue horizontal branch of the globular cluster M 15.
Seaton, M. J.; Auriere, M.; Adams, S.
Two stars belonging to the blue horizontal branch of the globular cluster M 15 have been observed in the ultraviolet with lUE and measurements have been made of their U B and V magnitudes. Measurements have also been made of B and V magnitudes for all the other stars which were in the JUE aperture and which are resolved in optical observations. Co…
IUE observations of stars in the M8 nebula.
Welsh, B. Y.
The early-type stars HD 164794, 164816, 164906 and 165052 belonging to the M8 nebula have been observed at high resolution using the IUE satellite. High velocity interstellar absorption components have been detected in each star's spectra at velocities of -32 and -53 km s-1. Such features must span across at least 8 pc in the nebula. A …