Search Publications
The shape and strength of circumstellar PAH emission bands.
Waters, L. B. F. M.; Beintema, D. A.; de Graauw, T. +9 more
We discuss the shape and strength of the emission bands observed in Short Wavelength Spectrometer (SWS) spectra of three carbon-rich evolved stars (Beintema et al., 1996A&A...315L.253B). The emission bands, due to stretching and bending modes of C-C and C-H bonds in Polycyclic Aromatic Hydrocarbons (PAHs), show large difference in strength and…
The X-ray and EUV spectrum of the dwarf nova VW Hydri in outburst and quiescence.
Belloni, T.; Verbunt, F.; Watson, M. G. +5 more
We combine ROSAT, Ginga, and EXOSAT observations to investigate the X-ray and extreme-ultraviolet fluxes of VW Hyi in quiescence and throughout an ordinary dwarf-nova outburst. We show that the quiescent spectrum is consistent with emission from material heated to ~12keV and cooling through the X-ray band to temperatures below our sensitivity rang…
Interstellar propagation of cosmic rays: analysis of the ULYSSES primary and secondary elemental abundances.
Duvernois, M. A.; Simpson, J. A.; Thayer, M. R.
The purpose of this investigation is to study the validity of the "leaky box" propagation model and determine some of its parameters. The pathlength distributions and their energy dependencies are derived from measurements of secondary-to-primary abundance ratios. A special charged particle telescope carried on the Ulysses spacecraft has provided …
SWS spectroscopy of the starburst galaxy NGC 3256.
Lutz, D.; Genzel, R.; Sturm, E. +10 more
We present 2.5-40µm ISO SWS spectra of the starburst galaxy NGC 3256. We have observed many fine-structure lines of various atomic species as well as three rotational transitions of molecular hydrogen. From the [SIII] 18µm/33µm line ratio we infer low electron densities of =~300cm^-3^ in the HII regions. The observed [NeIII]/[NeI…
Detection of far-infrared rotational lines of water vapour toward W Hydrae.
Lutz, D.; de Graauw, T.; Feuchtgruber, H. +5 more
We report the first detection of thermal water vapour emission from a circumstellar outflow. We have observed four far-infrared rotational emission lines of water vapour and one water absorption feature toward the evolved star W Hydrae, using the Short Wavelength Spectrometer (SWS) of the Infrared Space Observatory (ISO). Three of the emission lin…
The interstellar D/H ratio toward G191-B2B from GHRS observations.
Ferlet, R.; Vidal-Madjar, A.; Lallement, R. +3 more
We have observed the DA white dwarf G191-B2B using HST-GHRS to measure the interstellar D/H ratio. In order to derive an accurate structure of the line of sight, we have observed and analysed using a profile fitting procedure the interstellar lines of MgII (2800. and FeII (2344. high resolution using the Echelle B grating, and SiII (1190... (1206.…
High resolution UV spectroscopy of two hot (pre-) white dwarfs with the Hubble Space Telescope. KPD0005+5106 and RXJ2117+3412.
Rauch, T.; Werner, K.; Dreizler, S. +4 more
High resolution UV spectra of KPD0005+5106 and RXJ2117+3412 have been obtained with the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. The data were subject to a non-LTE model atmosphere analysis. For KPD0005+5106, the hottest known helium-rich white dwarf, the C and N abundances as well as an upper limit for O have been d…
ISOCAM mapping of the Whirlpool galaxy M51.
Elbaz, D.; Boulanger, F.; Okumura, K. +13 more
We have obtained the first images of the 6.75 and 15µm continuum emission in the Whirlpool galaxy with ISOCAM, the infrared camera of the ISO (Kesslet et al., 1996A&A...315L..27K). These data reveal the well-developed, spiral arms of the galaxy, in addition to diffuse emission between arms and in the outer regions of the disk. There is a…
Spectroscopic study of the outflowing disk winds of B[e] supergiants in the Magellanic Clouds.
Stahl, O.; Humphreys, R. M.; Zickgraf, F. -J. +3 more
We report on UV high resolution spectroscopic observations of R50 in the Small Magellanic Cloud, and R82 and HenS22 in the Large Magellanic Cloud obtained with the International Ultraviolet Explorer. The observed stars are supposed to represent edge-on cases of B[e] supergiants for which a two-component stellar wind model has previously been sugge…
Detection of an absorption feature at the position of the 4.27-µm band of solid CO_2_.
Henning, T.; Lemke, D.; Pfau, W. +3 more
We report observations of 13 young infrared sources associated with molecular clouds with ISO's spectrophotometer ISOPHOT-S in the wavelength range from 2.5 to 11.6µm. In addition to a number of well-known interstellar bands due to various molecular ices, a new band at 4.27µm was detected, which is very likely attributed to C=O stretch…