Search Publications
On the origin of the 13 mu m feature. A study of ISO-SWS spectra of oxygen-rich AGB stars
Mutschke, H.; Hron, J.; Kerschbaum, F. +3 more
We have derived a mean profile of the 13 mu m emission feature from 11 ISO spectra of oxygen-rich AGB stars and present an overview of the mineral species that could account for it. Our results can be summarized as follows: i) Spherical particles of alpha -Al_2O_3 (corundum) have a sharp emissivity maximum peaking at 12.7 mu m. The difference of 0…
PRONAOS observations of MCLD 123.5 + 24.9: cold dust in the Polaris cirrus cloud
Boulanger, F.; Abergel, A.; Giard, M. +10 more
We present submillimeter observations between 200 and 600 microns obtained with the French balloon-borne instrument SPM/PRONAOS toward the high latitude cirrus cloud MCLD 123.5+24.9 in the Polaris Flare. These sensitive measurements allow for the first time to study in details the submillimeter dust emission of cirruses at the arc minute scale. Th…
HST luminosity functions of the globular clusters M10, M22, and M55. A comparison with other clusters
Zoccali, M.; Piotto, G.
From a combination of deep Hubble Space Telescope V and I images with groundbased images in the same bands, we have obtained color-magnitude diagrams of M10, M22, and M55, extending from just above the hydrogen burning limit to the tip of the red giant branch, down to the white dwarf cooling sequence. We have used the color-magnitude arrays to ext…
The ionizing cluster of 30 Doradus. III. Star-formation history and initial mass function
Terlevich, R.; Bosch, G.; Selman, F. +1 more
A new method is presented and used to determine the IMF of the starburst cluster NGC2070. A new correction, the magnitude-limit correction is introduced, and shown to be crucial when attempting to derive the IMF in the presence of variable reddening when the photometry is not several magnitudes deeper than the fainter stars analyzed. Failure to ap…
A barred spiral at the centre of the giant elliptical radio galaxy Centaurus A
Sanders, D. B.; Cesarsky, C.; Sauvage, M. +7 more
We report observations at mid-infrared and sub-millimeter wavelengths of Centaurus A (Cen A, NGC 5128), the giant elliptical galaxy that harbors the closest radio loud Active Galactic Nucleus (AGN) to Earth. The dust emission from the deep interior of Cen A reveals a bisymmetric structure with a diameter of 5(') (5 kpc), centred at the AGN. This s…
HST images and properties of the most distant radio galaxies
Pentericci, L.; Macchetto, F.; Spinrad, H. +4 more
With the Hubble Space Telescope we have obtained images of 9 of the most distant radio galaxies. The galaxies, which have redshifts between z=2.3 and z=3.6, were observed with the WFPC2 camera in a broad band filter (F606W or F707W, roughly equivalent to V or R-band), corresponding to the near ultraviolet emission in the rest frame of the radio ga…
The NE BT VIII (lambda 770) resonance line: solar wavelengths determined by SUMER on SOHO
Wilhelm, K.; Curdt, W.; Dammasch, I. E. +1 more
The investigation of the source and acceleration of the solar wind was among the prime scientific goals of SOHO - ESA's and NASA's Solar and Heliospheric Observatory. For the coronal regions closest to the Sun, the bright extreme ultraviolet (EUV) resonance lines of the Ne viii spectrum at 770 { Angstroms} and 780 { Angstroms} with a formation tem…
Looking at the bright side of the rho Ophiuchi dark cloud. Far infrared spectrophotometric observations of the rho Oph cloud with the ISO
Olofsson, G.; Liseau, R.; White, G. J. +9 more
We present far infrared (45-195 mu m) spectrophotometric observations with the Iso-Lws of the active star forming rho Oph main cloud (L 1688). The [C ii] 158 mu m and [O i] 63 mu m lines were detected at each of the 33 positions observed, whereas the [O i] 145 mu m line was clearly seen toward twelve. The principal observational result is that the…
Coronal hole diagnostics out to 8Rsun
Doyle, J. G.; Teriaca, L.; Banerjee, D.
The Si viii line width measurements and N_e estimates based on SUMER observations are combined with LASCO and UVCS output to provide an overview of its variations with height above a polar coronal hole. From the combined dataset we find a radial dependence of the electron density, in the range 1-2 Rsun as r(-8) , from 2 to 4 Rsun
The Eagle Nebula's fingers - pointers to the earliest stages of star formation?
Pilbratt, G. L.; White, G. J.; Holland, W. S. +14 more
Molecular line, millimetre/submillimetre continuum, and mid-IR observations are reported of the opaque fingers which cross the Eagle Nebula. The fingers are surprisingly warm when viewed in the CO J= 3-2 lines, with kinetic temperatures approaching 60 K, although the lines are relatively narrow. Most of the mass in the fingers is concentrated in c…