Search Publications
Missions
Journals
Publication Years
IUE observations of absorption by hot gas in the nebula NGC6888
Nussbaumer, H.; Willis, A. J.; Wilson, R. +2 more
New UV observations of Wolf-Rayet stars obtained with the IUE satellite show narrow absorption components in the highly ionized species of Si IV and C IV. In the case of the WN6 star HD 192163 each resonance transition in the above ions exhibits two components, one undisplaced in wavelength and one blueshifted. The latter components are shown to a…
The ultraviolet spectrum of comet Seargent 1978m.
Keller, H. U.; Owen, T.; Smith, A. M. +5 more
UV spectrograms of Comet Seargent (1978m) have been obtained with the IUE satellite in the low- (1.8-nm) and high- (0.1-nm) dispersion modes. In the long-wavelength region (189-340 nm) emission bands of OH, CS, CO2(+), NH, and CO(+) can be identified, and the rotational structure of OH could clearly be resolved. In the short-wavelength region (119…
Observations of 3C 390.3 with the International Ultraviolet Explorer.
Perryman, M. A. C.; Ferland, G. J.; Longair, M. S. +1 more
Observations of the radio galaxy 3C 390.3 made with IUE are presented; these allow separate determinations of the Lyman/Balmer ratios in both the narrow and broad emission-line regions. The broad-line L-alpha/H-alpha ratio confirms the anomalous results found previously in quasars; in this case a ratio is found about 15 times smaller than that pre…
Oxygen VI in stellar winds.
Morton, D. C.
A review of observational evidence for five-times ionized oxygen (OVI) in stars and new high-resolution spectral scans obtained with Copernicus satellite are presented to show how this phenomenon varies with spectral type. The region of the OVI resonance doublet was observed in nine stars with the Copernicus spectrometer, and P Cygni profiles or s…
IUE UV spectra of the clumpy irregular galaxy MKN297
Casini, C.; Benvenuti, P.; Heidmann, J.
Clumpy irregular galaxies are made up of 5-10 bright clumps loosely scattered in a common envelope, have excess near-UV radiation and are giant compared with classic irregular galaxies1,2. Clumps are apparently ~100 times more massive than giant H II regions such as 30 Doradus or NGC604 (ref. 3). To get an insight into their properties …
Ultraviolet and X-ray observations of the BL Lac object MK 501.
Boksenberg, A.; Penston, M. V.; Snijders, M. A. J. +3 more
We present ultraviolet and X-ray satellite observations of Mk 501. The ultraviolet data after dereddening assuming E(B-V) = 0.11 show a power-law spectrum with α = 0.51+0.10-0.15. The visible and infrared fluxes are in good agreement with this power-law if the underlying elliptical galaxy has a luminosity MV = -22.…
Far ultraviolet line profiles in the Seyfert galaxy NGC 4151.
Boksenberg, A.; Penston, M. V.; Snijders, M. A. J. +2 more
Two high-resolution far-UV spectra (1150-2000 A) of the Seyfert 1 galaxy NGC 4151 are presented which were obtained from the IUE satellite with a resolution of about 10,000. It is found that the Ly-alpha line in NGC 4151 is asymmetric and rather narrow, that the Ly-alpha/H-beta ratio varies across the line, and that there are two absorption system…
On the energy distribution in Sirius B.
Boehm-Vitense, E.; Dettmann, T.; Kapranidis, S.
A spectrum of Sirius B in the wavelength region 1100-1900 A taken with the IUE satellite shows an absolute flux and spectral energy distribution in the continuum in agreement with theoretical white-dwarf models with T(eff) of 26,000 K plus or minus 1000 K for log g equals 8.65 and R equals 5.08 x 10 to the 8th cm. The Lyman-alpha profile is also i…
Ultraviolet spectroscopy of the extreme B supergiants P Cygni and zeta 1 Scorpii.
Hutchings, J. B.
High-dispersion IUE spectra of P Cyg and Zeta-1 Sco are presented. Both show extreme line blanketing by Fe III and similar ions, formed in a low-velocity stellar wind. P Cygni also shows the same phenomenon in Fe II, at somewhat higher velocity, and appears to be cooler and less reddened then its visible spectrum suggests. Both stars show weak evi…
The UV resonance lines of zeta 1 Sco.
Wolf, B.; Appenzeller, I.
The IUE satellite has been used to obtain high-resolution UV spectrograms of the extreme B1 supergiant Zeta-1 Sco. The observed line spectrum was found to be dominated by conspicuous P Cygni profiles or strongly blueshifted circumstellar absorption lines of the resonance transitions of Al II, Mg II, Si II, C II, Al III, Si IV, C IV, and N V, and o…