Search Publications
Photometric calibration of the international ultraviolet explorer (IUE) : low dispersion.
Savage, B. D.; Snijders, M. A. J.; Bohlin, R. C. +2 more
Absolute sensitivity curves for IUE low-resolution spectra are obtained by comparing IUE measurements of hot stars with the absolute energy distributions established for these objects by previous satellite and rocket experiments. The differences between these earlier experiments are discussed quantitatively, and a common absolute flux scale is pro…
Detailed characteristics of the high-energy gamma radiation from PSR 0833-45 measured by COS-B.
Bignami, G. F.; Hermsen, W.; Masnou, J. L. +11 more
A series of COS-B observations of the high-energy gamma-ray emission from PSR 0833-45 has been combined to derive detailed temporal and spectral characteristics of this source. The gamma-ray period of the pulsar was determined for the observations spanning the time interval October 1975 to June 1977. The variation of the period with time can be ex…
COS-B observations of high-energy gamma-ray emission from the Orion cloud complex.
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +11 more
Emission of high-energy gamma rays (between 70 and 5000 MeV) has been observed from the direction of the Orion cloud complex by the COS-B satellite. The emission is resolved and the existence of structure is apparent within the excess with two maxima coinciding with L 1630 and L 1641, i.e. the northern and the southern major clouds in the complex.…
A discussion on the nature of the Herbig-Haro object No 1 from its far UV spectrum.
Ortolani, S.; Dodorico, S.
The first far UV observation of an Herbig-Haro object as shown a strong continuum and emission lines of C IV and C II. The intensities of the UV emission lines are not easily interpreted in the framework of the shock wave models which have been proposed for HH objects. The continuum increases toward the high frequencies and is not consistent with …
Physical conditions and abundances of CNO elements in NGC 7027.
Panagia, N.; Perinotto, M.; Benvenuti, P.
Spectroscopic observations of NGC 7027 have been obtained with the IUE satellite. The data have been used to investigate the nature of the extinction toward the object, recognizing the existence of three components due to: (1) interstellar, (2) local, and (3) internal dust. The physical conditions in the O III zone have been determined by analyzin…
IUE observations of the Be stars HD 102567 (4U 1145-61), X Per and GAM Cas.
Hammerschlag-Hensberge, G.; Willis, A. J.; Wilson, R. +10 more
The first analysis of ultraviolet spectroscopic observation obtained with the IUE satellite of the Be stars HD 102567, X Per, and Gamma Cas, which all are associated with X-ray sources, is presented. The ultraviolet data for HD 102567 (4U 1145-61) consist of low-resolution spectra covering the wavelength range 1150-3200 A. The ultraviolet fluxes a…
IUE and ground based observations of the LMC star S Dor.
Wolf, B.; Cassatella, A.; Appenzeller, I.
IUE and ground-based spectrograms of the luminous Hubble-Sandage variable S Doradus of the Large Magellanic Cloud are presented. The two low-resolution IUE spectrographs covering the range 1150-3100 A are found to be dominated by strong absorption features of singly ionized metallic lines, with the resonance lines of C IV at 1548 and 1551 A and of…
IUE UV spectra of giant extragalactic H II regions.
Rosa, M.
The UV spectra (wavelengths between 1200 and 3200 A, resolution of 6 A) of the two extragalactic H II regions NGC 604 and NGC 5471 have been observed with the IUE satellite. The spectra show a continuum energy distribution and absorption lines (often with P Cygni profiles) characteristic of luminous early type stars, with a weak nebular emission s…
Absolute ultraviolet spectrophotometry with the TD-1 satellite. XI.
Beeckmans, F.; Hubert-Delplace, A. M.
Low resolution S 2/68 observations are used to show that Be stars of spectral type B0-B5 have a deficiency of ultraviolet radiation (at 2100 A) as compared to the visible with respect to normal stars of the same spectral type. The deficiency is statistically correlated with the strength of visual emission lines, with the existence of an infrared e…
Resonance line profiles in A type supergiants from IUE and Copernicus spectra.
Talavera, A.; Lamers, H. J. G. L. M.; Praderie, F.
A comparative study of UV resonance line profiles in one F0 type and four A type supergiants is made from a set of IUE spectra; the O I, C I, C II, Mg II, Al II, Al III, Si II, P II and Fe II ions are considered. Alpha Cyg (A 2 Ia) shows the most prominent velocity field effects on the profiles: they are broadened, asymmetric and shifted up to 240…