Search Publications
The rich far-infrared water vapour spectrum of W Hya.
Walker, H. J.; Omont, A.; Burgdorf, M. +40 more
We present an ISO Long Wavelength Spectrometer (LWS) grating spectrum of the oxygen-rich AGB star W Hya from 43-197µm. The spectrum is dominated by a forest of water vapour emission lines, confirming that H_2_O molecules are the dominant coolants of the winds of these stars. We have constructed an outflow model for the H_2_O spectrum of W Hy…
The cooling of the white dwarf in VW Hyi.
Gänsicke, B. T.; Beuermann, K.
We present an analysis of the post-outburst evolution of VW Hyi based on the available IUE archive data. The spectrum closest to the previous outburst (~0.5days) shows a non-negligible contribution of a disc remnant while the white dwarf (WD) dominates the later observations. Following an outburst, the accretion-heated WD cools exponentially to a …
Mid-Infrared spectrum of the zodiacal light.
Cesarsky, C.; Perault, M.; Boulanger, F. +10 more
Using the mid-infrared camera on the Infrared Space Observatory (ISO), the spectrum of a relatively empty piece of sky, dominated by zodiacal light, was measured from 5 to 16.5µm wavelength. The spectrum has no spectral features brighter than 15% of a blackbody fit to entire spectrum; the temperature of the fit is 261.5+/-1.5K. No galactic o…
HIPPARCOS distances and mass limits for the planetary candidates: 47 Ursae Majoris, 70 Virginis, and 51 Pegasi
Evans, D. W.; Arenou, F.; Lindegren, L. +19 more
Distances to the recently-discovered planetary system candidates, 47 UMa, 70 Vir and 51 Peg, are presented, based on absolute trigonometric parallaxes from the global reduction of the ESA Hipparcos astrometry satellite data. Standard errors of the parallaxes are in the range 0.66-0.76mas (milliarcsec), with resulting distances accurate to around 1…
Combined stellar structure and atmosphere models for massive stars. II. Spectral evolution on the main sequence.
Schaerer, D.; Schmutz, W.; de Koter, A. +1 more
In Schaerer et al. (1995, Paper I) we have presented the first ``combined stellar structure and atmosphere models'' (CoStar) for massive stars, which consistently treat the entire mass loosing star from the center out to the outer region of the stellar wind. The models use up-to-date input physics and state-of-the-art techniques to model both the …
First data from the ISOPHOT FIR Serendipity survey.
Kessler, M. F.; Burgdorf, M.; Lemke, D. +10 more
The ISOPHOT Serendipity Survey fills the otherwise unused slew time between ISO's fine pointings with measurements in an unexplored wavelength regime near 200µm. First results of the Serendipity Survey demonstrate its capabilities in the detection of extragalactic point sources as well as in investigations of the galactic infrared cirrus. Wi…
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…