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Damping and frequency reduction of the f-mode due to turbulent motion in the solar convection zone
Murawski, K.; Mȩdrek, M.; Roberts, B.
Solar f-mode properties were observed recently with high accuracy using high-resolution Michelson Doppler Imager (MDI) data from SOHO (Duvall et al. 1998). According to these observations, linewidths increase with wavenumber k and the f-mode frequency omega is significantly lower than the frequency omega_0 given by the simple dispersion relation o…
Starburst nuclei: ISO observations and models
Siebenmorgen, R.; Krügel, E.; Zota, V.
1.) We present photometric data of three starburst galaxies (Mkn 496, Mkn 1116, NGC 6000) obtained with the Infrared Space Observatory (ISO) in the wavelength bands 2.5-11.6 mu m (P-40) and 120-200 mu m (P-22). In all galaxies, we detect the 9.7 mu m silicate absorption feature and strong emission from PAHs; only the 3.3 mu m band is below the sen…
Distance and absorption of the tails in the CG 30/CG 31/CG 38 complex. an application of a (V-I)_0 - M_V main sequence relation derived from the HIPPARCOS and TYCHO catalogues
Knude, J.; Nielsen, A. S.; Jønch-Sørensen, H.
From a mosaic of rather deep V and I images of the CG 30/CG 31 region we report distances and absorptions of these and other interesting interstellar features, the distances and absorptions estimates are based on shifting a new (V-I)_0 - M_V relation obtained from nearby, presumably unreddened Hipparcos stars with luminosity class V classification…
The ultraviolet variations of the post-AGB star HD 89353
Parthasarathy, M.; Monier, R.
Based on an analysis of all low resolution spectra of HD 89353 (HR 4049) obtained with the International Ultraviolet Explorer (IUE) over several years and uniformly reprocessed, we report on large ultraviolet variations for this star whose amplitude increases towards long wavelengths. Ultraviolet maximum and minimum occur respectively at phase 0.5…
ISOPHOT observations of narrow line Seyfert 1 galaxies
Polletta, M.; Courvoisier, T. J. -L.
Broad infrared spectra (7-200 mu m) of four NLSy1 galaxies, obtained with the imaging photo-polarimeter (ISOPHOT) on-board ISO, are presented. ISOPHOT data have been analyzed applying a (non standard) method that is described in details. The infrared spectra of the four selected NLSy1 galaxies have been analyzed in order to derive the distribution…
The molecular cloud core M 17-North: New ISOCAM observations
Henning, Th.; Cesarsky, D.; Klein, R.
We present spectro-imaging data of the molecular cloud core M17-North. The data have been obtained with the ISOCAM camera on board of the Infrared Space Observatory (ISO) using the circular variable filters (CVF). The spectra have a spectral resolution of about 40. They are dominated by PAH emission bands. A band at 16.6{ mu m} is detected which i…
Solar oscillations: time analysis of the GOLF p-mode signal
Turck-Chièze, S.; Ulrich, R. K.; Boumier, P. +5 more
We determine the intrinsic phase lag of the GOLF data for the solar p-mode velocity deduced either from one of the narrow band photometers working alternatively on blue and red wing of the sodium lines. The timing of the ``blue wing'' velocity coming from the current GOLF data is given in respect to the ground-based observations. The phase lag for…
Opacities along the line of sight to and in the atmosphere of the white dwarf in the close detached DAO+dM binary RE J0720-318
Barstow, M. A.; Hubeny, I.; Burleigh, M. R. +1 more
We present the results from a multi-wavelength study of the mixed H+He composition DAO white dwarf
The absolute magnitude of K0V stars from BT HIPPARCOS parallaxes
Groenewegen, Martin A. T.; Schrijver, Hans; Oudmaijer, Renéd.
We investigate the properties of K0V stars with Hipparcos parallaxes and spectral types taken from the Michigan Spectral Survey. The sample of 200 objects allows the empirical investigation of the magnitude selection (Malmquist) bias, which appears clearly present. By selecting those objects that are not affected by bias, we find a mean absolute m…
ISO SWS/LWS observations of SN 1987A
Sollerman, J.; Lundqvist, P.; Spyromilio, J. +5 more
We report on observations of SN 1987A with ISO SWS/LWS made 9-11 years after the explosion. No emission from the supernova was seen. In particular, the upper limits on the fluxes of [Fe I] 24.05 µm and [Fe II] 25.99 µm on day 3 999 are ~ 1.1 Jy and ~ 1.4 Jy, respectively. Assuming a homogeneous distribution of (44) Ti inside 2 000 km s…