Search Publications
Ripple correction of high-dispersion IUE spectra: blazing echelles.
Barker, P. K.
An iterative differential correcion technique designed to remove the blaze function of an echelle grating directly from observed spectral data is mathematically defined and applied to high-dispersion images acquired with the International Ultraviolet Explorer. Quantitative measurements of ripple correction accuracy demonstrate that the technique i…
IUE observations of the high-velocity symbiotic star AG Draconis. II.The spectral variations during 1979-1983.
Altamore, A.; Baratta, G. B.; Friedjung, M. +2 more
High quality IUE spectra of AG Dra gathered during 1979-81 were examined in concert with data taken at VILSPA. Visual bursts were detected in 1980 and 1983 and were associated with order of magnitude changes in the UV continuum and emission lines. Variability was persistent in the UV and He II lines after the bursts while the C IV line displayed s…
Quantification of the order overlap problem for IUE high resolution spectra (SWP camera). A correction algorithm.
Bianchi, L.; Bohlin, R. C.
A quantification of the order overlap in IUE high resolution spectra is obtained, for the SWP camera, by comparison of line depths measured in IUE and Copernicus spectra. The amount of order overlap is found to be about 32 percent of the net spectrum at 1150 A, decreasing to zero at about 1400 A, for data extracted with the most recent production …
The abundance of interstellar chlorine in the galaxy.
Bromage, G. E.; Harris, A. W.
The results of a large-scale survey of chlorine abundance in interstellar H I gas are presented. The abundances are derived from measurements of 40 interstellar-absorption-line equivalent widths in far-ultraviolet stellar spectra from the Copernicus and International Ultraviolet Explorer (IUE) satellites. It is found that the relative chlorine abu…
The high-ionization and excited-state interstellar lines in the Carina Nebula : a giant HII region in absorption.
Walborn, N. R.; Heckathorn, J. N.; Hesser, J. E.
The dominant component of the highly ionized and excited-state interstellar species seen in the ultraviolet toward stars within the Carina Nebula has been found to have a heliocentric radial velocity of about -30 km/s. This velocity is known to correspond to the near edge of the expanding H II region, as shown by the double optical nebular emissio…
Absolute spectrophotometry of Wolf-rayet stars from 1200 to 7000 A : a cautionary tale.
Conti, P. S.; Garmany, C. D.; Massey, P.
It is demonstrated that absolute spectrophotometry of the continua of Wolf-Rayet stars may be obtained over the wavelength range 1200-7000 A using IUE and optical measurements. It is shown that the application of a 'standard' reddening law to the observed data gives spurious results in many cases. Additional UV extinction is apparently necessary a…
The origin of low-velocity absorption components in the MG II resonance lines of hybrid-chromosphere stars.
Linsky, J. L.; Brown, A.; Drake, S. A.
It is argued that the low-velocity absorption features seen in the Mg II resonance lines of seven confirmed and three probable hybrid-chromosphere stars are interstellar rather than circumstellar in origin. From a comparison of radial velocities based on all available spectra in the International Ultraviolet Explorer (IUE) archives with estimates …
EXOSAT observations of GH 2215^-086 : detection of the X-ray pulse period
Watson, M. G.; McHardy, I. M.; Cook, M. C.
A 2.8 hr observation of the intermediate polar H2215 - 086 using the Exosat Medium Energy experiment has revealed a strong, quasi-sinusoidal modulation of the hard X-ray flux with a period (20.65 + or - 0.32 min) consistent with, and in phase with, that of the large amplitude optical variations. The detection of this hard X-ray modulation confirms…
Two multifrequency observations of 3C 371.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +14 more
We present observations of 3C 37t, made at frequencies from the radio to the ultraviolet, which were coordinated during two short time intervals separated by 3 months. We also present 1 keV X-ray flux densities measured at a different time. The multifrequency measurements indicate spectral steepening at visual wavelengths, and that an extrapolatio…
IUE low dispersion observations of symbiotic objects.
Sahade, J.; Fontenla, J. M.; Brandi, E.
The results of the study of low dispersion IUE ultraviolet spectra of 20 symbiotic stars and of the binary RY Scuti are presented in tables and graphs. The continuous and the line spectra are analyzed and discussed. Variations in line intensity and in the continuum are reported.