Search Publications
Mass Flow in Interacting Binaries Observed in the Ultraviolet
Kondo, Yoji
Recent satellite observations of close binary systems show that practically all binaries exhibit evidence of mass flow and that, where the observations are sufficiently detailed, a fraction of the matter flowing out of the mass-losing component is accreted by the companion and the remainder is lost from the binary system. The mass flow is not cons…
Chemically Peculiar Stars of the Upper Main Sequence.
Maitzen, H. M.
The Local Interstellar Medium - a Test-Bed for the Galactic Interstellar Medium
Molaro, P.; Beckman, J. E.; Vladilo, G. +1 more
We outline a method to explore the column density of the Local Interstellar Medium (LISM) using absorptions in the resonance H and K lines of MgII. The intrinsic strengths of these lines in the temperature and density conditions prevailing in warm clouds (Teff<104 K) in the LISM allows them to be used to explore many lines…
A New Narrow-Line Seyfert 1 Galaxy: IRAS 1652+395
Malkan, M. A.; Mandolesi, N.; Partridge, B. +3 more
Multiwavelength observations--from radio to X-rays--of IRAS 1652+395, a far-infrared and X-ray source serendipitously discovered in the field of the BL Lac object Mrk 501, are reported. They show that IRAS 1652+395 is a new Seyfert 1 galaxy at a redshift of z = 0.069. The Balmer emission lines are only slightly broader (~ 1000 km s^-1^ FWHM) than …
High energy gamma-rays from cygnus X-3
Wu, Mei; Li, Tipei
Simultaneous observations by the ESA satellite COS-B show that the 2-12 keV X-rays and 150-5000 MeV gamma-rays of Cyg X-3 are negatively correlated. A clear gamma-ray image of Cyg X-3 can be obtained between June 1977 and June 1980, when the X-ray emission was low, to yield a flux of P(E > 100MeV) ~ 1 × 10 -6cm -2s -1…
In situ exploration of the dusty coma of comet P/Halley at Giotto's encounter: Nucleus emission and production rates from temporal variability
McDonnell, J. A. M.; Pankiewicz, G. S.; Perry, C. H.
Flux-time profiles from the DIDSY and PIA experiments, taken at Giotto's encounter with comet P/Halley, are used to study coma dust dynamics and the nucleus emission. A comparison of the data with a `fountain' model, incorporating variable source function and grain type is made. Local enhancements such as jets, envelopes and terminators are analys…
The VV Cephei Star V641 Cassiopeiae
Guinan, Edward F.; Shaw, J. Scott
Ultraviolet spectra of the variable star V641 Cas taken with the IUE satellite have confirmed the VV Cephei nature of this object. The observations are consistent with the variable being a M3 I + B2 V-III system with E(B-V) = 0.55 mag lying in the Perseus arm of the Galaxy. In spite of V641 Cas having the largest light variation in the visible of …
Giotto Comet Halley Dust Impact experiment: Studies of discrete impact events
McDonnell, J. A. M.; Alexander, W. M.; Goad, H. +2 more
Analysis of discrete pulse height data from specific individual events of the Giotto Comet Halley Dust Impact Detectors DID-1 and DID-4 has been completed. The cumulative flux for the mid-size range of this Giotto comet dust experiment has been studied and results are presented. The technique employed in the investigation utilized a constant numbe…
Ultraviolet studies of the interstellar gas in the direction of the stars AE Aur (09.5V) andθ 2 Ori A (09.0V)
Avcioglu, Kamuran; Mentese, H. Huseyin
We have studied high-resolution SWP spectra of AE Aur andθ2 Ori A, obtained from the International Ultraviolet Explorer Satellite; and derived curve of growth and column densities ofCII,CII*, AlII, SiII, SiII*,SII, CrII, FeII, NiII, and ZnII. It has been possible to fit these ions on one empirical curve of growth w…
A correlation of energetic particle flux anisotropies with magnetic field variations in- and outside the coma of comet Halley
Neubauer, F. M.; Daly, P. W.; Ip, W. -H. +4 more
Anisotropies and energy spectra of cometary ions (mainly O+, OH+, H2O+) derived from the EPA/EPONA measurements on board of Giotto during the encounter (12-14 March 1986) with comet Halley are used to study the acceleration processes taking place in the vicinity of the comet. Further evidence was found f…