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Ultraviolet spectra of planetary nebulae. IV. The CIII 2297 dielectronic recombination line and dust absorption in the CIV 1549 resonance doublet.
Harrington, J. P.; Lutz, J. H.; Seaton, M. J.
Calculations by Storey confirm, as suggested in Paper I of the present series, that dielectronic recombination via low-lying auto-ionizing states is important for the calculation of the ionization equilibria of carbon ions. These processes also produce various spectrum lines, of which one is C III 2p2 1D → 2s 2p 1P…
The ultraviolet spectrum of the active elliptical galaxy NGC 1052.
Boksenberg, A.; Penston, M. V.; Snijders, M. A. J. +1 more
Low resolution IUE observations of NGC 1052 in both the long and the short wavelength regions are reported along with optical multi-aperture photometry. It is found that the ultraviolet energy distribution of NGC 1052 is similar to that of other normal galaxies observed with IUE, having a large excess at short wavelengths above the extrapolation o…
An analysis of the planetary nebula NGC 2867.
Keyes, C. D.; Aller, L. H.; Ross, J. E. +1 more
Spectroscopic observations made with the Anglo-Australian Telescope are combined with IUE data to provide material for a theoretical analysis of NGC 2867. Except for the S II forbidden line, line intensities in the optical region can be represented reasonably well by a simple theoretical model based on Balick's (1975) work. The model is used to as…
Ultraviolet spectra of planetary nebulae - the C II 1335 dielectronic recombination lines in IC 418.
Clavel, J.; Seaton, M. J.; Flower, D. R.
High-dispersion observations of IC 418 by the IUE satellite show the C II lines (1) 1334.53 A, (2) 1335.66 A, and (3) 1335.71 A. The profiles are of the P Cygni type, a form expected to result from scattering in the expanding nebular shell, with a mean velocity difference between nebular emission lines and interstellar absorption lines of 47 km/se…
High velocity interstellar C IV and SI IV toward two stars in the I Per OB association.
Gondhalekar, P. M.; Phillips, A. P.
Blue-shifted interstellar C IV, Si IV and Al III lines have been detected in the IUE spectra of the B2Ia stars HD 14818 and HD 14143; which are members of the I Per OB association. The radial velocities and column densities of these high ion state lines are similar toward the two stars. These observations, together with previous optical and radio …
Outburst spectra of UZ Ser.
Jones, D. H. P.; Pringle, J. E.; Hassall, B. J. M. +4 more
August-1980 observations of UZ Ser in outburst and approaching quiescence are presented. Spectral fits to simultaneous ultraviolet and optical data in the wavelength range 1250-8000 A are examined. An upper limit of the reddening E(B-V) = 0.1 mag is found, and the ultraviolet spectrum at outburst is observed to show broad shallow absorption lines.
Far UV observations of late K and M type stars.
Stickland, D. J.; Sanner, F.
The far UV spectra of 15 late K and M type giant and supergiant stars have been recorded with IUE. They exhibit rather flat continua which change strength with spectral type and appear to originate in the low chromosphere. A number of chromospheric emission lines have also been measured and identifications are suggested for many of them.
IUE observations of the high redshift QSO 1101-264.
Boksenberg, A.; Snijders, M. A. J.
Low-resolution spectral observations of the high-redshift quasar Q 1101 obtained by the IUE satellite are presented. Low-dispersion observations were obtained in the spectral regions 1150-1950 A and 1850-3350 A, and reduced by the improved extraction method of Snijders (1980). The quasar is found to be 18 + or - 5% brighter in the long-wavelength …
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.
Presence of MG II emission in R CrB at maximum light.
Kameswara-Rao, N.; Nandy, K.; Bappu, M. K. V.
The high dipersion spectrum of R CrB in the long wavelength obtained near its maximum with the International Ultraviolet Explorer shows the presence of chromospheric Mg II emission. For comparison the spectrum of Gamma Cyg was obtained immediately afterwards. The Mg II emission width of R CrB is found to be the same as that of Gamma Cyg.