Search Publications
A laboratory database of solid CO and CO_2_ for ISO.
van Dishoeck, E. F.; Schutte, W. A.; Tielens, A. G. G. M. +4 more
We present laboratory measured infrared spectra of mixtures containing CO and CO_2_ at low temperatures. The profiles and peak position of the absorption features due to these species are very sensitive to molecular environment, temperature, irradiation history and particle shape. Illustrative examples of these variations are briefly discussed. We…
The rate of turbulent evolution over the Sun's poles.
Balogh, A.; Horbury, T. S.; Forsyth, R. J. +1 more
Ulysses magnetic field observations in the polar heliosphere have revealed the presence of a population of turbulent fluctuations on small scales with a power spectral index near 5/3 and its extension to progressively larger scales with solar distance. Using the spectral index - calculated from the second order structure function - as a tracer of …
The ISO/LWS far infrared spectrum of IRC+10 216.
Walker, H. J.; Omont, A.; Ade, P. A. R. +41 more
We present an ISO Long Wavelength Spectrometer (LWS) grating spectrum of the carbon-rich circumstellar envelope -CSE- of IRC+10216 between 43 and 197µm. The spectrum consists of strong dust emission plus a forest of emission lines from CO, HCN, H^13^CN and vibrationally excited HCN (ν_2_=1^1^,2^0,2^ and ν_1,3_=1). All the CO lines between J=…
A detached dust shell surrounding the J-type carbon star Y Canum Venaticorum.
Waters, L. B. F. M.; Kawara, K.; Izumiura, H. +2 more
This paper reports the first clear detection of a detached dust shell surrounding the prototypical J-type carbon star Y CVn in 90µm and 160µm maps taken with the ISO/ISOPHOT. The projected inner radius of the shell is 180"-190", corresponding to (6.4-7.1)x10^17^cm at a distance of 250pc. The shell thickness is obtained to be (2-5)x10^1…
The photometric calibration of the ISO Short Wavelength Spectrometer.
Lutz, D.; Heras, A. M.; Waters, L. B. F. M. +29 more
We give an overview of the photometric calibration of the Short Wavelength Spectrometer (SWS) through the Performance Verification phase. The basic strategy for deriving absolute flux densities from detector output for the grating and Fabry-Perot sections of SWS is reviewed, and the results are demonstrated with 2.4 - 45µm spectra of represe…
Constraints on high-speed solar wind structure near its coronal base: a ULYSSES perspective.
Phillips, J. L.; Wang, Y. -M.; Feldman, W. C. +1 more
Ulysses plasma data at high heliographic latitudes were studied to develop constraints on the structure of the corona at the base of the high-speed solar wind. Salient features of the flow poleward of +/-60° revealed: 1) low variances of all bulk flow parameters, 2) parameter values that agree with those measured during high-speed conditions in th…
H_2_ infrared line emission from S 140: a warm PDR.
Draine, B. T.; Bertoldi, F.; Sternberg, A. +4 more
ISO SWS spectra of H_2_ pure rotational and ro-vibrational transitions, as well as [FeII], and [SiII] fine structure lines were obtained for one position on the photodissociation region (PDR) adjacent to the bright rim of the S 140 HII region. The gas density is =~10^4^cm^-3^ and the incident UV flux χ=~400 at the location of the ionization front.…
ISO-SWS spectrophotometry of galactic Wolf-Rayet stars: preliminary results.
Beintema, D. A.; de Graauw, T.; Morris, P. W. +12 more
ISO-SWS spectra of seven late-type galactic Wolf-Rayet stars are discussed. A high resolution spectrum (2.3-29.6µm, λ/{DELTA}λ=~820-1700) of the WC8 star WR11 (γ^2^ Vel) is shown and its Ne abundance is discussed. Medium resolution spectra (λ/{DELTA}λ=~250-600) of the WC8-9 stars WR48a, WR98a, WR104, WR112 and WR118 show the broad circumstel…
The infrared spectrum of comet C/1995 O1 (Hale-Bopp) at 4.6 AU from the Sun.
Altieri, B.; Jorda, L.; Lamy, P. L. +7 more
Comet C/1995 O1 (Hale-Bopp) was observed on 27 April 1996 with the ISOPHOT instrument of ISO when it was at 4.6 AU from the Sun. The 2.5-12µm spectrum was recorded at low resolution. We present here the preliminary results of this observation. The 2.5-5µm spectrum shows emission in the CO_2_ ν_3_ band. The CO_2_ production rate is abou…
Discovery of four white dwarfs with strong magnetic fields by the Hamburg/ESO Survey.
Reimers, D.; Jordan, S.; Bade, N. +3 more
Four magnetic white dwarfs have been found in the course of the Hamburg/ESO Survey for bright QSOs. The objects have been selected as QSO candidate on the basis of its blue continuum and the apparent absence of strong hydrogen or helium lines. One star, HE1211-1707, shows a rather fast spectral variability: both the strength and the position of th…