Search Publications
An estimate of the D/H ratio in Jupiter and Saturn's regular icy satellites - Implications for the Titan Huygens mission
Mousis, O.
The solar nebula model described by Dubrulle (\cite{Dubrulle1993}) and Drouart et al. (\cite{Drouart1999}) is used to predict the D/H ratio in H2O ice of both Jovian and Saturnian regular satellite systems. These calculations take into account recent scenarios of formation of Jupiter and Saturn's large regular icy satellites developed f…
Conversion of bulk kinetic energy into radiation in AGNs and GRBs: Particle transport effects
Vainio, R.; Schlickeiser, R.; Pohl, M.
We investigate the spatial structure of collisionless collision fronts in relativistic outflows interacting with ambient material. As a result of the interaction, ambient particles are picked up by the outflow and generate transverse plasma waves via streaming instabilities. Pick-up particle transport under the influence of self-generated turbulen…
On the analysis of band 3 of the ISO-SWS calibration sources
Shipman, R. F.; Decin, L.; Kester, D. +4 more
We analyse ISO-SWS 01 (R ∼ 1500) 12-27.5 µm (band 3) spectra of the 10 standard calibration stars with the highest flux using synthetic spectra generated from (MARCS) atmosphere models. The comparison between the observed and synthetic spectra reveals the quality of (1) the atmospheric model construction and subsequent synthetic spectra comp…
η Carinae: The 1998 brightening and the smearing-out effect
Sterken, C.; van Genderen, A. M.
A comparison of broad-band photometry of the Homunculus (ground-based data) and of broad-band and narrow-band photometry of the central region (HST-based) from 1997 to 2003 reveals that, apart from the brightening in 1998, the Homunculus as well as the central star varied in a very similar way. This excludes smearing-out effects as an explanation …
The composite starburst/AGN nature of the superwind galaxy NGC 4666
Palazzi, E.; Cappi, M.; Franceschini, A. +6 more
We report the discovery of a Compton-thick AGN and of intense star-formation activity in the nucleus and disk, respectively, of the nearly edge-on superwind galaxy NGC 4666. Spatially unresolved emission is detected by BeppoSAX only at energies <10 keV, whereas spatially resolved emission from the whole disk is detected by XMM-Newton. A promine…
The discovery of hard X-ray emission in the persistent flux of the Rapid Burster
Frontera, F.; Goldoni, P.; Stella, L. +3 more
We report the first detection with INTEGRAL of persistent hard X-ray emission (20 to 100 keV) from the Rapid Burster (MXB 1730-335), and describe its full spectrum from 3 to 100 keV. The source was detected on February/March 2003 during one of its recurrent outbursts. The source was clearly detected with a high signal to noise ratio during the sin…
Physical parameters of helium-rich subdwarf B stars from spectral energy distributions
Jeffery, C. S.; Ahmad, A.
We present effective temperatures and angular radii for eleven helium-rich subdwarf B stars. These are measured using spectral energy distributions from archival IUE spectra and existing optical and infrared photometry. The data have been analysed using a grid of high-gravity helium-rich LTE model atmospheres and a χ2-minimization proce…
Estimating stellar parameters from spectra. I. Goodness-of-fit parameters and lack-of-fit test
Aerts, C.; Decin, L.; Molenberghs, G. +2 more
Estimating stellar parameters from spectrophotometric data is a key tool in the study of stellar structure and stellar evolution. Although many methods have been proposed to estimate stellar parameters from ultraviolet (UV), optical and infrared (IR) data using low, medium or high-resolution observational data of the target(s), only a few address …
The stellar content of the ring in NGC 660
Tikhonov, N. A.; Galazutdinova, O. A.; Hagen-Thorn, V. A. +2 more
We present the results of stellar photometry of the polar-ring galaxy
The corona of HD 199178 (V 1794 Cygni)
Gondoin, P.
HD 199178 (V 1794 Cygni), a chromospherically active late-type giant with a high X-ray luminosity, was observed by the XMM-Newton space observatory. Series of lines of highly ionized Fe and several Lyman lines of hydrogen-like ions are visible in the reflection grating spectra, most notably from O and Ne. Analysis results suggest a scenario where …