Search Publications
Correlation of gamma-ray fluxes with southern hemisphere CO data.
Manchester, R. N.; Wolfendale, A. W.; Whiteoak, J. B. +3 more
A new radio survey of the C-12O molecule in the Galactic plane covering the longitude range l:294 - 358 deg is compared with the flux of high energy gamma rays in the same region. A good correlation between the two is found, and it is shown that the data are consistent with the hypothesis that most of the gamma-ray flux is produced by the cosmic-r…
IUE observations of high velocity gas towards the M 16 nebula.
Welsh, B. Y.
The star HD 168183, which is part of the giant H II region-molecular cloud complex of M16 (NGC 6611), has been observed at high resolution using the IUE satellite. High velocity interstellar absorption components have been detected at velocities of -83, -38 and +40 km s-1 and it is proposed that a stellar wind-driven shock-front, intera…
Radial velocity and profile variations of the ultraviolet circumstellar lines in ζ tauri
Hirata, R.; Dawanas, D. N.
The radial velocity and profile variations of UV lines of the shell star ζ Tau have been examined in the IUE spectra obtained in 1978–1982. The neutral atoms, and once or twice-ionized ions (exceptCII, AlIII, SiIII resonance lines) follow the same velocity variations as in the visual spectra, while the SiIV andCIV resonance lines show a constant n…
Multifrequency observations of the quasi-stellar object Ton 1542.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +3 more
The authors present single-epoch multifrequency data for the radio-quiet low-redshift QSO Ton 1542, spanning radio through ultraviolet wavelengths. They measure a 3σ upper limit of 9.2 mJy for the 20.3 GHz flux density. The first ultraviolet spectrum of this object is presented and discussed. The authors find a particularly strong excess of flux d…
Spectroscopic Segregation in Binary Systems
Darius, J.
Binary systems displaying spectroscopic segregation, whereby line spectra of the two components overlap little or not at all in wavelength, account for a small subset of LUV objects (late-type ultraviolet). Optical and ultraviolet (IUE) spectra for one such system, HD 15351+UV0225+13 (F4-5 V+sdO), are presented and a few related systems described.…
Rapid short-term pulse-period variations in Vela X-1 (4U 0900-40)
van der Klis, M.; Bonnet-Bidaud, J. M.
Results are presented of an analysis of 83 days of 2-12 keV X-ray observations of Vela X-1 (4U 0900-40) obtained during three separate pointings with the ESA COS-B satellite. The pulsation period is shown to undergo very rapid intrinsic changes, at a rate of up to P˙/P ~ 10-1 yr-1 during intervals of a few days. The lower val…
Ultraviolet spectrophotometry of isolated galaxies.
Brosch, N.; Greenberg, J. M.; Rahe, J. +1 more
The authors have obtained ultraviolet spectrophotometry of five isolated galaxies with the IUE which confirms the existence of the ultraviolet excesses first found by UBV photometry. Observations from the optical part of the spectrum to the radio bands are combined with the ultraviolet data to explain the nature of the UV excesses as the signature…
A superluminous object in the Large Cloud of Magellan
Savage, B. D.; Cassinelli, J. P.; Mathis, J. S.
The superluminous object R136a of the nebula 30 Dor in the Large Cloud of Magellan is characterized, summarizing the results of recent optical and (IUE) UV observations. Photographs, spectra, and diagrams are provided; and the techniques used to determine the parameters of the object are explained. The UV spectra exhibit a typical P Cygni profile …
Epsilon Aurigae
Hack, M.
The results of recent ultraviolet and deep infrared observations of the latest eclipse of the binary Epsilon Aurigae are reported. The observations were performed with both the International Ultraviolet Explorer (IUE) satellite, and with the three-meter Infrared Telescope at Mauna Kea, Hawaii. On the basis of new theoretical models, several explan…
EXOSAT observation of 'Geminga'
Caraveo, P. A.; Bignami, G. F.
IE 0630 + 178, the X-ray source associated with the gamma-ray source Geminga (2CG195 + 04), has been observed by the EXOSAT satellite. The X-ray images, recorded by the channel-multiple-array instruments at the foci of the two low-energy telescopes equipped with different filters, show clearly the source. The flux value, computed from the count ra…