Search Publications
Grids of model spectra for WN stars, ready for use
Hamann, W. -R.; Gräfener, G.
Grids of model atmospheres for Wolf-Rayet stars of the nitrogen sequence (WN subclass) are presented. The calculations account for the expansion of the atmosphere, non-LTE, clumping, and line blanketing from iron-group elements. Observed spectra of single Galactic WN stars can in general be reproduced consistently by this generation of models. The…
Bright OB stars in the Galaxy. I. Mass-loss and wind-momentum rates of O-type stars: A pure H\alpha analysis accounting for line-blanketing
Puls, J.; Markov, H.; Markova, N. +1 more
We study mass-loss and wind momentum rates of 29 Galactic O-type stars with luminosity classes I, III and V by means of a pure H\alpha profile analysis and investigate to what extent the results compare to those originating from a state-of-the-art, complete spectral analysis. Our investigation relies on the approximate method developed by \citet{P…
Study of the properties and spectral energy distributions of the Herbig AeBe stars HD 34282 and HD 141569
Rauer, H.; Schneider, J.; Eiroa, C. +21 more
We present a study of the stellar parameters, distances and spectral energy distributions (SEDs) of
Radiation-driven winds of hot luminous stars. XV. Constraints on the mass-luminosity relation of central stars of planetary nebulae
Pauldrach, A. W. A.; Hoffmann, T. L.; Méndez, R. H.
We present a new model atmosphere analysis of nine central stars of planetary nebulae. This study is based on a new generation of realistic stellar model atmospheres for hot stars; state-of-the-art, hydrodynamically consistent, spherically symmetric model atmospheres that have been shown to correctly reproduce the observed UV spectra of massive Po…
Hα variability of the recurrent nova T Coronae Borealis
Marziani, P.; Zamanov, R.; Stanishev, V. +1 more
We analyze Hα observations of the recurrent nova
A study of the expanding envelope of Nova V1974 Cyg 1992 based on IUE high resolution spectroscopy
Altamore, A.; Rossi, C.; González-Riestra, R. +2 more
We have carried out a detailed analysis of the IUE archival high resolution spectra of the classical nova V1974 Cyg 1992. The main UV resonance lines show P Cygni profiles in the first days, which change into symmetric pure emission lines, and then slowly become fainter and narrower. Lines of higher ionization species reach their peak luminosity l…
Beyond the iron group: Heavy metals in hot subdwarfs
O'Toole, S. J.
We report the discovery of strong photospheric resonance lines of Ga III, Ge IV, Sn IV and Pb IV in the UV spectra of more than two dozen sdB and sdOB stars at temperatures ranging from 22 000 K to 40 000 K. Lines of other heavy elements are also detected, however in these cases more atomic data are needed. Based on these discoveries, we present a…
Abundances of Planetary Nebulae IC 418, IC 2165 and NGC 5882
Pottasch, S. R.; Beintema, D. A.; Feibelman, W. A. +1 more
The ISO and IUE spectra of the elliptical nebulae
On the importance of the few most massive stars: The ionizing cluster of NGC 588
Vílchez, J. M.; González Delgado, R. M.; Cerviño, M. +3 more
We present the results of a double analysis of the ionizing cluster in
Physical interpretation of the NGC 7469 UV/X-ray variability
Maraschi, L.; Nandra, K.; Petrucci, P. O. +1 more
We present a re-analysis of the simultaneous ∼30 day IUE/XTE observation of NGC 7469 done in 1996. Our main progress in this paper, in comparison to previous spectral analyses (Nandra et al. \cite{nan98,nan00}), is to adopt and fit directly to the data a detailed model of the Comptonized spectrum. This firstly allows one to fit simultaneously the …