Search Publications
The quasi-parallel shock wave detected by ULYSSES on day 92:109.
Balogh, A.; Smith, E. J.; Phillips, J. L. +1 more
On day 92:109, at about 5.4 AU and 9° south, Ulysses detected a strong quasi-parallel shock wave leading an interaction region. We describe this singular event on different temporal scales, placing emphasis on the magnetic field observations. The solar wind preceding the shock presented very unusual long-lived conditions: for about one day the int…
Starburst activity in X-ray and FIR luminous galaxies: the case of NGC 4619 and IRAS 15564+6359.
Mas-Hesse, J. M.; Rodriguez-Pascual, P. M.; Cerviño, M. +1 more
We have analyzed the multiwavelength (soft X-rays to far infrared) energy distribution of IRAS 15564+6359 and NGC 4619, two galaxies previously not classified as active galaxies but found during the ROSAT All Sky Survey to be very luminous in the X-ray and far infrared (FIR) ranges. By comparison with population synthesis evolutionary models we ha…
Comparison of the Carlsberg optical reference frame with the International Celestial Reference Frame.
Fabricius, C.; Jones, D. H. P.; Morrison, L. V. +4 more
The optical positions of 63 extragalactic nebulae measured in the frame defined by the annual series of Carlsberg Meridian Catalogues Nos 1-8 are compared with their VLBI radio positions in the International Celestial Reference Frame. The differences between these radio and optical positions are interpreted as showing the global distortion of the …
First UV spectrum of the AM Herculis star RX J1940.1-1025.
Staubert, R.; Friedrich, S.; La Dous, C.
We present the first UV spectrum of the polar RX J1940.1-1025, taken with the IUE satellite in the wavelength range between 1190A to 1950A. The phase averaged spectrum shows strong emission lines of CIV (1550A), NV (1240A), SiIV (1397A) and HeII (1640A) which are typical for AM Her stars. The line ratios of NV/SiIV and NV/CIV, and the continuum fl…
Generation of plasma turbulence and radio emission at the front of interplanetary MHD shocks.
Ledenev, V. G.
Based on spectral observations of turbulence and radio emission in the interplanetary medium from the Ulysses spacecraft, we describe processes responsible for the formation of energetic particle fluxes, the generation of Langmuir and ion acoustic turbulence, and the radio emission at the front of a quasi-perpendicular MHD shock wave. It is shown …
Branches and loops in the X-Ray colour-colour diagram of Cygnus X-3.
van der Klis, M.; Smit, J. M.
We present an analysis of EXOSAT ME X-ray colour-colour diagrams of Cygnus X-3. Our sample contains all the Cygnus X-3 data collected during EXOSAT's operational life time and covers a total of 190 hours. The colour-colour diagrams display X-ray spectral variations with the 4.8 hour period and show the spectral distinction between the `high' and t…
Collision of comet Shoemaker-Levy 9 with Jupiter: impact study of two fragments from the timing of precursor events.
Sekanina, Z.
The impacts of fragments K and R of comet Shoemaker-Levy 9 are examined with the aims to interpret the timing of the observed precursors to the main thermal emission event and to correlate the results of ground-based infrared observations with a variety of observations made onboard the Galileo spacecraft. Analysis of the phenomena associated with …
Kilometre-wave radio observations of solar type III bursts by ULYSSES compared with decametre-wave observations from the Earth.
MacDowall, R. J.; Lecacheux, A.; Hoang, S. +1 more
Observations of solar type III bursts, made at kilometric frequencies by the radio receiver of the Ulysses Unified Radio and Plasma Wave (URAP) investigation, are compared with simultaneous observations, made at decametric frequencies at the Nancay Radio Astronomy Station of the Paris-Meudon Observatory, during the period following the spacecraft …
Relative astrometry with Hipparcos: double stars with orbital motion.
Badiali, M.; Cardini, D.; Emanuele, A. +2 more
During the Hipparcos data analysis an algorithm was developed to study orbital motion in double stars and to derive the seven Dommanget parameters in the positive cases. Three approaches were followed: linear motion model, quadratic motion model and orbital model. In the last model the algorithm needs sufficiently good starting values and it has b…
A search for 3He enhancements in SEP and CIR-associated events with Ulysses/HI-scale.
Biesecker, D. A.
We identify 17 solar energetic particle (SEP) events with enhanced abundances of 3He relative to 4He detected by the Heliosphere Instrument for Spectra, Composition, and Anisotropy at Low Energies (HI-SCALE) on the Ulysses spacecraft. These events were all detected while Ulysses was within 5deg of the ecliptic plane, but at d…