Search Publications
What powers luminous infrared galaxies?
Lutz, D.; Genzel, R.; Sturm, E. +8 more
Based on the initial data sets taken with the ISO short wavelength spectrometer (SWS) we present a first discussion of the source of luminosity of (ultra-)luminous infrared galaxies (ULIRGs). By comparison of observations of 2.5-45µm lines to classical starbursts and active galactic nuclei and by modelling of the line emission we show that t…
The 6.0 and 6.8µm absorption features in the spectrum of NGC 7538: IRS9.
Prusti, T.; de Graauw, T.; van Dishoeck, E. F. +6 more
Short Wavelength Spectrometer observations of the 6.0 and 6.8µm absorption features towards the obscured young stellar object NGC 7538: IRS9 are presented and compared to the features of a number of species measured in the solid phase. It is found that while solid H_2_O provides the bulk of the 6µm band, additional absorption is requir…
Pulsation models of δ Scuti variables. I. The high-amplitude double-mode stars.
Christensen-Dalsgaard, J.; Petersen, J. O.
The relations between high-amplitude δ Scuti stars and the much more abundant low-amplitude δ Sct variables are not clear. Both groups have similar periods and seem to have almost the same basic physical properties, although their light-curve characteristics are very different. In the last few years much improved observational data have been publi…
Infrared spectrophotometry of NGC 7023 with ISOCAM.
Palazzi, E.; Perault, M.; Abergel, A. +4 more
We present spectrophotometric observations of the reflection nebula NGC 7023 obtained with the ISOCAM Circular Variable Filter (CVF) in the spectral range 5.15 to 16.5µm. Maps in the 16µm continuum emission and in the Unidentified Infrared Bands (UIBs) have been obtained. The continuum emission peaks at the dense interface between the …
Spatial variation of >40MeV/n nuclei fluxes observed during the ULYSSES rapid latitude scan.
Kunow, H.; Wibberenz, G.; Potgieter, M. S. +7 more
In this paper we present fluxes of galactic cosmic ray nuclei with energies above 40MeV/n observed by the Kiel Electron Telescope on board the Ulysses spacecraft during the fast scan from the South Pole (September 1994) to the North Pole (July 1995). This part of the Ulysses orbit gives us the unique opportunity to investigate spatial modulation o…
ISO-SWS observations of solid state features towards RAFGL 7009S.
Boulanger, F.; Ehrenfreund, P.; Dartois, E. +6 more
We report the detection of various solid state molecular features in the SWS01 spectrum of a protostellar object, RAFGL 7009S. Identified molecules include H_2_O, CO, CO_2_ together with ^13^CO_2_ and CH_4_. Other less firmly identified features are observed that appear in laboratory spectra of UV photolysed ices. We thus confirm the previous dete…
Variation of electron-strahl width in the high-speed solar wind: ULYSSES observations.
McComas, D. J.; Forsyth, R. J.; Phillips, J. L. +2 more
Halo electron velocity distributions have been surveyed during the first full Ulysses southern polar pass from January 1994 through April 1995. The data examined range from approximately 50degS heliolatitude to the maximum poleward extent of the Ulysses orbit, approximately 80degS, and then back through the solar equator to 35degN heliolatitude. D…
The X-ray source in non-magnetic cataclysmic variables.
Beuermann, K.; Verbunt, F.; van Teeseling, A.
We have analysed all available rosat pspc observations of non-magnetic cataclysmic variables. The VY Scl and non-SU UMa systems have harder X-ray spectra than the SU UMa and UX UMa systems. The old nova RR Pic has a very soft X-ray spectrum and might not be an ordinary non-magnetic cataclysmic variable. There appears to be no clear correlation of …
Mid-Infrared Imaging Spectroscopy in Ophiuchus.
Rouan, D.; Perault, M.; Boulanger, F. +13 more
The dust emission spectrum between 5 and 16µm has been measured at the northern edge of the dense cloud in Ophiuchus at a position where the radiation field intensity is estimated to be 10-20 times the mean Solar neighborhood value. The spectrum shows the well known emission bands at 6.2, 7.7, 8.6, 11.3 and 12.7µm. ISO allows to detect…
Infrared absorption of H_2_O toward massive young stars.
van Dishoeck, E. F.; Helmich, F. P.
We present ISO-SWS observations of absorption lines of gas-phase water within its bending vibrational mode at 6µm toward four massive young stars, which cover a range in physical parameters. Hot water with an excitation temperature >200K is detected toward GL 2136 and GL 4176, in addition to GL 2591 discussed by Helmich et al. (1996A&…