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The giant haloes of NGC 6543 and 6826.
Walsh, J. R.; Clegg, R. E. S.; Middlemass, D.
Long-slit spectra at several positions on the large faint haloes of NGC 6543 and 6826 were obtained using IPC spectrograph and CCD detectors. It is shown that the halo emission is thermal in origin, and that the forbidden O III electron temperature is higher in each halo than in its central nebula. Halo electron temperature values of 14,700 K for …
Ultraviolet observations of stellar winds in Be and 'normal' B non-supergiant stars.
Prinja, Raman K.
Model profile fits to high-resolution IUE C IV, Si IV, and Si III spectra are used to produce a homogeneous set of wind-velocity and column-density measurements for 40 early-type Be stars and 40 nonemission, nonsupergiant B stars. The mass-loss characteristics in the Be and normal B stars are compared. Results on stellar wind morphology, velocitie…
The absolute magnitudes of RR Lyrae stars - I. X Arietis.
Jameson, R. F.; Fernley, J. A.; Kilkenny, D. +4 more
A Baade-Wesselink analysis based on the infrared flux method of Blackwell and Shallis (1977) is used to estimate the temperature and angular diameter of X Ari at all phases of the pulsational cycle. These results are then used to determine the radius, distance, and absolute magnitude. New UV, optical and IR observations for this metal-poor star ar…
The absolute magnitudes of RR Lyrae stars - II. DX Delphini.
Jameson, R. F.; Fernley, J. A.; Lynas-Gray, A. E. +2 more
UV, IR and visual photometry of the short-period RR Lyrae star DX Del is presented and treated by means of the Blackwell and Shallis (1977) IR Flux Method-based formulation of the Baade-Wesselink method. Upon correcting to common reddening, extinction, and radial-velocity conversion factors, as well as applying the Baade-Wesselink analysis of Burk…
A 2597 : another massive cooling flow.
Fabian, A. C.; Johnstone, R. M.; Crawford, C. S. +1 more
We present X-ray, optical and ultraviolet observations of the rich cluster A2597 and confirm the presence of a central cooling flow. The intracluster gas is cooling at a rate of ~370 M_sun_ yr^-1^ and we observe extended optical line-emitting gas around the central galaxy over a radial distance of ~25 kpc. Examination of the blue continuum spectru…
Broad emission line variability in 3C 273.
Zheng, W.; Wilson, R.; O'Brien, P. T.
We find that the broad Ly α H{BETA} and Fe II emission lines in the luminosity quasar 3C 273 vary by 10-30 per cent on time-scales less than a year. All the line variations occurred during approximately the same period. The line cores vary more than the wings, indicating that the line variability involves only pan of the BLR. The line variability …
IUE archive observations of dwarf nova WZ SGE during outburst.
Naylor, T.
Observations from the International Ultraviolet Explorer archive are used to show that during the 1978 outburst of the dwarf nova WZ Sge, its orbital light curve displayed dips, similar to those seen during the outbursts of other high-inclination dwarf novae. These dips are thought to be due to obscuration of the inner regions of the accretion dis…
High-resolution Hα spectroscopy of the bright RS CVn system HR 7275.
Eker, Zeki
HR 7275 is a bright, long-period (28 day), single-lined RS CVn binary. High-resolution (0.36 A) and good signal-to-noise ratio echelle spectra do not show any clear evidence of the secondary in the system on spectral lines. Also, absence of a continuum on a low-resolution UV spectrum (IUE merged log) and the known mass function imply a main-sequen…
Anomalously high intercombination line ratios in symbiotic stars; extreme Bowen pumping ?
Feibelman, W. A.; Bhatia, A. K.; Kastner, S. O.
International Ultraviolet Explorer observations of the ratio of the O III intercombination lines near 1660 A are assembled, showing that the observed ratios in symbiotic stars are significantly higher than the theoretically predicted optically thin limit of 2.5. The presence of an enhancing physical process is thereby indicated. It is suggested th…
Ultraviolet spectra of a large sample of quasars. I. Data and data reduction.
Gondhalekar, P. M.
Ultraviolet spectrophotometric data on all quasars (Z_e_ > 0.1) obtained with IUE from 1978 to the end of 1986 have been retrieved from IUE archive and re-extracted directly from the photometrically corrected images. A spectrum extraction procedure was used to maximize the signal-to-noise ratio and discriminate against spurious events outside t…