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UV spectroscopy of planetary nebulae.
Perinotto, M.; Benvenuti, P.
The planetary nebulae IC 2149 and NGC 2440, 3242, and 6826 are investigated with spectra obtained using the IUE satellite in the spectral range 1150-3200 A at a resolution of 7 A. The physical conditions in the nebulae are derived, as are the abundances of C, N, O, and Ne. It is noted that carbon is essentially solar while nitrogen appears slightl…
IUE monitoring of the spatial distribution of the H Ly-alpha emission from Jupiter
Feldman, P. D.; Moos, H. W.; Clarke, J. T.
North-south spatial maps of the Jovian H Lyman-alpha emission observed with the IUE satellite support the identification of a marked longitudinal asymmetry in the equatorial brightness, with the peak around lambda III(1965) = 50-100 deg longitude, and show a weaker planet-wide equatorial brightening above the level predicted by a plane-parallel la…
The ultraviolet spectrum of the planetary nebula NGC 6572.
Flower, D. R.; Penn, C. J.
The ultraviolet emission line spectrum of NGC 6572 has been analyzed in conjunction with visual and infrared observations of the nebula. Particular attention is paid to the C/O abundance ratio for which a value of 1.1 is derived. Gaseous Mg is found to be depleted in the outer regions of the nebula.
The ultraviolet spectrum of the X-ray source 2A 0526-33.
Bonnet-Bidaud, J. M.; Mouchet, M.; Ilovaisky, S. A. +1 more
Low resolution spectra of the X-ray source 2A0526-33 have been obtained with IUE. The X-ray source 2A0526-33 is confirmed as a cataclysmic variable from both its line and continuum ultraviolet spectra. Observed emission lines are similar to those found in other systems, such as EX Hya (Bath et al., 1980), AM Her or SS Cyg at quiescence (Fabbiano e…
Theoretical and observed UV energy distributions of 7 globular clusters
Nesci, R.
A grid of synthetic UV spectra is computed and the effects of the various parameters are shown. A comparison with the integrated spectra of 7 globular clusters is made with satisfactory results, suggesting that constraints on the HB morphology and the chemical composition may be achieved on the basis of the UV fluxes alone. A spread in the observe…
An ultraviolet study of NGC 7662.
Perinotto, M.; Benvenuti, P.
Spectroscopic observations obtained by the IUE of the planetary nebula NGC 7662 are discussed. Physical conditions in the central regions of the nebula are determined from the intensities of the O III and Ne IV lines, resulting in an electron temperature profile which increases with the ionization potential of the ions, in agreement with predictio…
The ultraviolet spectrum of the high redshift QSO B2 1225+31.
Boksenberg, A.; Snijders, M. A. J.; Pettini, M.
We present low-resolution, near-ultraviolet observations of the bright (V=15.87), high redshift (Zem ≈ 2.2) QSO B2 1225+31, obtained with the IUE long wavelength camera. These spectra provide an important extension to the large body of optical and radio work carried out on this object. The QSO continuum in the ultraviolet agrees well wi…
Lanning 10 and 33 : the X-ray, uv, and optical fluxes.
Szkody, P.; Crosa, L.
UV spectra from IUE, optical spectroscopy, broad band photometry, and upper limits on the X-ray flux from Einstein are used to specify the characteristics of Lanning 10 and 33. Data on Lanning 33 are consistent with a 22,000 K Be star at a distance of 5 to 7 kpc, and Lanning 10 appears to include a F5-G0 star plus a hot component greater than 35,0…
Boron and beryllium in early-type peculiar stars.
Sadakane, K.; Jugaku, J.
High-dispersion ultraviolet spectra of eleven early-type peculiar stars have been obtained with the IUE. The B II resonance line at 1362.46 Å is clearly present in two Mn-Hg stars (κ Cnc and HR 7.361) and in 20 Tao, while the presence of this line cannot be confirmed in the remaining eight stars. The B II subordinate lines near 1624 Å and the B II…
IUE observations of four planetary nebulae.
Johnson, H. M.
Low dispersion spectra of NGC 6905 and NGC 5189 are reproduced. These are nebulae with 'O VI sequence' nuclei. Line features are identified and classified according to site in the nucleus or the nebula; their flux densities are measured above continuum and presented before and after correction for interstellar extinction. The behavior of the line …