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Ultraviolet interstellar absorption toward stars in the Small Magellanic cloud. II. SK 159.
Fitzpatrick, E. L.
On the basis of a study of high-dispersion spectra of stars in the Large and Small Magellanic Clouds (LMC and SMC) obtained with the International Ultraviolet Explorer (IUE) satellite, Savage and de Boer (1979, 1981) have detected the Milky Way halo gas. The existence of gaseous coronae around both the LMC and SMC was also suggested. The evidence …
The far-ultraviolet energy distribution of Sirius B from Voyager 2.
Wesemael, F.; Holberg, J. B.; Hubeny, I.
Observations of Sirius obtained with the Voyager 2 ultraviolet spectrometer clearly reveal the presence of flux from the white dwarf Sirius B at wavelengths between 950 and 1100 A. These observations are in good agreement with all previous ultraviolet observations of Sirius B, and in particular with the IUE observations of Boehm-Vitense, Dettmann,…
SI III emission line strengths in low density plasmas.
Dufton, P. L.; Keenan, F. P.; Kingston, A. E.
Theoretical emissivity ratios appropriate to homogeneous optically thin plasmas are presented for the Si III lines at 1883 and 1892 Å. These lines are a useful density diagnostic for Ne ≥ 104cm-3, their use being illustrated for the planetary nebulae NGC 7662 and V1016 Cygni.
The presence of Si3+ and C3+ in the wind of AB Aur.
Talavera, A.; Catala, C.
The Herbig Ae variable AB Aur (spectral type A0) exhibits a line spectrum characteristic of a stellar wind. IUE observations of the Si IV and C IV resonance lines in AB Aur are reported. These lines are strong and in absorption. Two models can explain the presence of Si3+ and C3+ in the wind of AB Aur: a "remote chromosphere"…
Accretion of mass in Algol.
Molaro, P.; Cugier, H.
Several high resolution IUE spectra of Algol taken in 1978 and 1979 are analysed. Variable additional absorption components for the ultraviolet resonance lines of Mg II, Al III, and Si IV are detected. The additional components show eclipsing effects indicating that they originate in a region near the primary star, Algol A. Moreover, their behavio…
The ultraviolet spectrum of a strongly reddened, high-excitation Herbig-Haro object.
Bohm-Vitense, E.; Bohm, K. H.
Short- and long-wavelength IUE spectra of the rather strongly reddened, high radial velocity Herbig-Haro object HH 32A have been obtained. The object is well known for its large positive radial velocity and for its unusually large velocity dispersion. In consequence of the large ultraviolet extinction, the spectra are faint. The semiforbidden C II…
The spectrum of the Be star HD 110432.
de Freitas Pacheco, J. A.; Codina, S. J.; Lopes, D. F. +1 more
The UV spectrum of HD 110432, a B0.5IIIe star, is described. The IUE spectra present broad absorption photospheric lines, very narrow absorption lines of interstellar origin and narrow absorption lines of highly ionized species (N V, C IV, and Si IV) displaced to the short wavelengths at velocities of about -1350 km s-1. The authors hav…
Ultraviolet observations of the peculiar supernova remnant in NGC 4449.
Gull, T. R.; Raymond, J. C.; Fesen, R. A. +1 more
IUE spectra were obtained of the emission region in the irregular galaxy NGC 4449 that has been identified as a young, oxygen-rich supernova remnant embedded in an H II region. The spectra show a blue continuum with a strong C IV 1550 P Cygni feature. Comparison to spectral standard stars observed with IUE shows similarities to O3-O7 V and early B…
The stellar population of the nucleus of M 33 from an analysis of itslambda-lambda 1200-3000 A spectrum.
Benvenuti, P.; Dodorico, S.; Ciani, A.
The λλ1200 - 3000 Å spectrum of the nucleus of M33 is used in conjunction with U, B, V photometry as input to a linear programming method to determine the stellar population of the system. No astrophysical constraints but modifications in the stellar library (which includes Population II objects) were used to explore different evolutionary histori…
Main-sequence B stars with strong winds in the core of NGC 6231.
Savage, B. D.; Massa, D.; Cassinelli, J. P.
Low-dispersion IUE observations of 13 main sequence B0 - 2 stars in the Sco OB1 association are presented. Eleven of these are in the rich open cluster NGC 6231. Most of the NGC 6231 stars have strong UV resonance lines which are inconsistent with either their spectral types or the rest of their UV spectra. A high-dispersion IUE spectrum of one of…