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Densities and Abundances of Hot Cometary Ions in the Coma of P/Halley
Balsiger, H.; Ip, W. -H.; Goldstein, B. E. +3 more
The densities of the hot component in the ion population observed in the P/Halley coma by the ion mass spectrometer aboard the Giotto spacecraft has been recomputed, and the results are reported. Except for protons and H2(+), all densities are found to be at least an order of magnitude higher than predicted by the physicochemical model of Schmidt …
The Binary Feige 24: The Mass, Radius, and Gravitational Redshift of the DA White Dwarf
Thorstensen, John R.; Vennes, Stephane; Shipman, Harry L. +1 more
Observations are reported which refine the binary ephemeris of the Feige 24 system, which contains a peculiar hot DA white dwarf and an M dwarf with an atmosphere illuminated by extreme ultraviolet radiation from the white dwarf. With the new ephemeris and a set of IUE high-dispersion spectra, showing phase-dependent redshifted C IV, N V, and Si I…
An Interactive Companion to the S Star HD 35155
Johnson, Hollis R.; Ake, Thomas B., III; Ameen, Mudhaffer M.
Low-dispersion UV spectra taken by the IUE satellite of an S star HD 35155 are presented. It is shown that the spectra contain strong emission lines of multiply ionizes species and an excess continuous emission shortward of 2000 A. Because neither the photospheres nor chromospheres of S stars are expected to produce multiply ionized ions, the emis…
Probing the Galactic Halo along the 3C 273 Sight Line Using IUE
York, Donald G.; Blades, J. C.; Bohlin, Ralph C. +2 more
High-resolution spectra of the QSO 3C 273 were obtained in 1989 and added to two spectra recorded in 1982. The co-added spectra represent 600,000 s of integration at a resolution of 30 km s^-1^ from 1200 to 2000 A. The line of sight passes through the Virgo Cluster the entire halo of the Milky Way, at Galactic latitude b = 64^deg^, and foreground …
IUE Spectra of the Eclipsing Binary NN Serpentis
Wood, Janet H.; Marsh, Thomas R.
Low-resolution SWP and LWP IUE spectra are used to fit the temperature and angular radius of the white dwarf in the detached eclipsing binary NN Ser. It is found that the redenning to the system has E(B-V) of 0.05 +/-0.05, the white dwarf temperature is 60,000 +/-10,000 K, and the age of the white dwarf is less than 10 exp 7. The shape of eclipse …
Energy Distributions of Symbiotic Novae
Kwok, Sun; Bryan, Greg L.
The IRAS low-resolution spectra of three recent symbiotic novae are fitted with a dust continuum radiative transfer model. It is found that the dust shells are detached from the photosphere and that the sizes of the inner radii are correlated with times since outburst. An analysis of the IUE spectra of HM Sge at different epochs suggests that the …
EXOSAT Observations of the X-Ray Source 2S 0114+65
Singh, K. P.; Apparao, Krishna M. V.; Bisht, P.
The Exosat satellite made X-ray observations of the Be star binary system 2S 0114 + 65 on five occasions during the period 1983-1986. Several X-ray flares of a few hours duration were observed. The hardness ratio shows an inverse correlation with intensity, indicating that the intensity variation is due to absorption. This implies density irregula…
The X-Ray Cooling Flow in the Cluster of Galaxies around PKS 2354-35
Remillard, Ronald A.; Tuohy, I. R.; Schwartz, Daniel A. +1 more
A position measured with the HEAO 1 Scanning Modulation collimator suggested the group of galaxies surrounding the radio galaxy PKS 2354-35 as the identification of the bright, hard X-ray source 4U 0009 - 33 = 3A 2356 - 341 = 1H 2355 - 350. We confirm this identification with measurements of the position and spatial extent using the EXOSAT CMA det…
The Ultraviolet Continuum and the Fluorescent H 2 Lines in Low-Excitation Herbig-Haro Objects
Boehm, K. H.; Solf, J.; Scott, D. M.
Long-exposure IUE observations are used here to determine the spatial distribution of the fluorescent H2 line emission in the low-excitation objects HH 43 and HH 47. In HH 43, the spatial distribution of the fluorescent H2 line emission has a width equal to or smaller than the width of the point-spread function of IUE, while both the short-wavelen…
EXOSAT Observations of the Seyfert 1 Galaxy NGC 3516
Ghosh, K. K.; Soundararajaperumal, S.
Results of the X-ray spectra (0.1-10 keV) of the Seyfert galaxy NGC 3516 are presented based on the EXOSAT observations obtained on four epochs between 1985/308 and 1985/340. The data were obtained from the EXOSAT archives. The soft X-ray (0.1-2 keV) flux of this galaxy varied by a factor of ~3 on the time scales of 2 days, and that for the hard X…