Search Publications
The ultraviolet spectrum of the Seyfert galaxies NGC 3516 and NGC 5548.
Ulrich, M. H.; Boisson, C.
The observation of the UV spectrum of Seyfert nuclei has made it possible to conduct a comparison of the UV spectra of active nuclei over a wide range of absolute luminosities. In a study of the two Seyfert galaxies NGC 3516 and NGC 5548 with the International Ultraviolet Explorer (IUE) satellite, Boggess et al. (1978) have found that remarkable v…
Ultraviolet and optical observations of the dwarf novae VW and WX Hydri during outburst.
Schwarzenberg-Czerny, A.; Pringle, J. E.; Wade, R. A. +3 more
Simultaneous spectrophotometry is presented in the range 1200-7000 A of the dwarf novae, at quiescence and maximum. The continuum spectra are compared with the standard model disk spectrum and, with one exception, the fit is poor. The assumptions that the disk is both steady-state and blackbody are reconsidered, and it is pointed out that a nu to …
IUE observations of Markarian 3 and 6 : reddening and the nonstellar continuum.
Malkan, M. A.; Oke, J. B.
The authors have used IUE visual and infrared observations to study the spectra of the Seyfert 2 galaxies NGC 1068 and Markarian 3, and the Seyfert 1.5 galaxy Markarian 6. The starlight in these galaxies is reddened by 0.01, 0.18, and 0.06 mag in EB-V, respectively; the forbidden lines are reddened by 0.29, 0.27, and 0.27 mag, respectiv…
Rocket detection of ultraviolet emission from neutral oxygen and sulfur in the IO Torus
Durrance, S. T.; Feldman, P. D.; Weaver, H. A.
Ultraviolet spectra (1150-1750 Å) of the Io plasma torus were obtained using a rocket-borne telescope and spectrometer in 1981 May. The spectra show emissions of neutral oxygen and sulfur as well as the first three ionization states of sulfur. A comparison with IUE spectra indicates that these emissions may have different spatial distributions or …
A study of ultraviolet spectra of zeta Aur/VV CEP systems. II. Mass loss of supergiants in zeta Aur, 32 CYG and 31 Cyg.
Reimers, D.; Hempe, K.; Che, A.
This paper describes a method for the determination of mass loss rates of red giants in spectroscopic eclipsing binaries. A non-spherical, three-dimensional line transfer code has been applied to investigate the wind and mass loss of the K supergiants in ζ Aur, 32 Cyg and 31 Cyg. The authors compare theoretical line profiles with IUE observations …
High-velocity iron absorption lines in supernova remnant 1006.
Gull, T. R.; Sarazin, C. L.; Wu, C. -C. +1 more
The very strong, broad absorption lines of a sdOB star continuum shown in the International Ultraviolet Explorer spectrum of the Schweizer-Middleditch star projected near the center of supernova remnant SNR 1006 are investigated. It is found that strong Fe(+) resonance absorption lines are present whose centers show zero radial velocity while thei…
Absorption by halo gas in the direction of M 13.
Savage, B. D.; de Boer, K. S.
A high velocity cloud in the direction 1 = 59 degrees, b = 41 degrees is detected in absorption at approximately -80 km/s in high dispersion IUE spectra of the blue star Barnard 29 in the globular cluster M13. The cloud is also seen in the H I 21 cm emission data of Kerr and Knapp (1972). Its radial velocity agrees with Giovanelli's data (1980, 19…
Do all barium stars have a white dwarf companion ?
Lambert, D. L.; Dominy, J. F.
International Ultraviolet Explorer short-wavelength, low-dispersion spectra were analyzed for four barium, two mild barium, and one R-type carbon star in order to test the hypothesis that the barium and related giants are produced by mass transfer from a companion now present as a white dwarf. An earlier tentative identification of a white dwarf c…
A study of the low-mass X-ray binary HZ HER/HER X-1 using IUE and optical data.
Howarth, I. D.; Wilson, B.
An extensive body of uniformly extracted IUE spectrophotometry of HZ Her/Her X-l is presented. To interpret these data a light-curve synthesis model comprising a distorted, X-ray heated primary accompanied by an accretion disc is developed. Roche geometry is used for the star, and the X-ray shadow thrown by the disc accounted for. The model's para…
The young Sun and the atmosphere and photochemistry of the early Earth
Giampapa, M. S.; Imhoff, C. L.; Canuto, V. M. +2 more
The origin and evolution of the Earth's early atmosphere depend crucially on the dissipation time tN of the primitive solar nebula, SN. Using different theories of turbulence, we estimate that for a 0.1 Msolar SN, tN is 2.5-8.3Myr. Because accretion times are usually much longer, we conclude that most planetary acc…