Search Publications
Visual binary orbits and masses POST HIPPARCOS
Söderhjelm, Staffan
The parallaxes from Hipparcos are an important ingredient to derive more accurate masses for known orbital binaries, but in order to exploit the parallaxes fully, the orbital elements have to be known to similar precision. The present work gives improved orbital elements for some 205 systems by combining the Hipparcos astrometry with existing grou…
The HST view of FR I radio galaxies: evidence for non-thermal nuclear sources
Capetti, A.; Chiaberge, M.; Celotti, A.
Unresolved nuclear sources are detected by the Hubble Space Telescope in the great majority of a complete sample of 33 FR I radio galaxies belonging to the 3CR catalogue. The optical flux of these Central Compact Cores (CCC) shows a striking linear correlation with the radio core one over four decades, arguing for a non-thermal synchrotron origin …
Source counts from the 15 mu m ISOCAM Deep Surveys
Aussel, H.; Elbaz, D.; Clements, D. L. +11 more
We present the results of the five mid-IR 15 mu m (12-18 mu m LW3 band) ISOCAM Guaranteed Time Extragalactic Surveys performed in the regions of the Lockman Hole and Marano Field. The roughly 1000 sources detected, 600 of which have a flux above the 80% completeness limit, guarantee a very high statistical significance for the integral and differe…
Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures
Allende Prieto, C.; Lambert, D. L.
The Hipparcos mission has made it possible to constrain the positions of nearby field stars in the colour-magnitude diagram with very high accuracy. These positions can be compared with the predictions of stellar evolutionary calculations to provide information on the basic parameters of the stars: masses, radii, effective temperatures, ages, and …
Mapping the contours of the Local bubble: preliminary results
Crifo, F.; Lallement, R.; Welsh, B. Y. +1 more
We present preliminary results from a long-term program of mapping the neutral absorption characteristics of the local interstellar medium, taking advantage of Hipparcos stellar distances. Equivalent widths of the NaI D-line doublet at 5890 Å are presented for the lines-of-sight towards some 143 new target stars lying within 300 pc of the Sun. Usi…
Open clusters with Hipparcos. I. Mean astrometric parameters
Arenou, F.; Robichon, N.; Turon, C. +1 more
New memberships, mean parallaxes and proper motions of all 9 open clusters closer than 300 pc (except the
ISOCAM observations of the Hubble Deep Field reduced with the PRETI method
Aussel, H.; Elbaz, D.; Cesarsky, C. J. +1 more
We have developed a new ISOCAM data reduction technique based on wavelet analysis, especially designed for the detection of faint sources in mid-infrared surveys. This method, the Pattern REcognition Technique for Isocam data (PRETI) has been used to reduce the observations of the Hubble Deep Field (HDF) and flanking fields with ISOCAM at 6.75 (LW…
Mass-loss rates and luminosity functions of dust-enshrouded AGB stars and red supergiants in the LMC
Waters, L. B. F. M.; van Loon, J. Th.; Loup, C. +5 more
A radiative transfer code is used to model the spectral energy distributions of 57 mass-losing Asymptotic Giant Branch (AGB) stars and red supergiants (RSGs) in the Large Magellanic Cloud (LMC) for which ISO spectroscopic and photometric data are available. As a result we derive mass-loss rates and bolometric luminosities. A gap in the luminosity …
Revisiting Hipparcos data for pre-main sequence stars
Arenou, F.; Robichon, N.; Bertout, C.
We cross-correlate the Herbig & Bell and Hipparcos Catalogues in order to extract the results for young stellar objects (YSOs). We compare the distances of individual young stars and the distance of their presumably associated molecular clouds, taking into account post-Hipparcos distances to the relevant associations and using Hipparcos interm…
Weak ice absorption features at 7.24 and 7.41 MU M in the spectrum of the obscured young stellar object W 33A
de Graauw, Th.; van Dishoeck, E. F.; Whittet, D. C. B. +7 more
ISO-SWS observations of the highly obscured young stellar object W 33A reveal two broad absorption features centered at 7.24 and 7.41 mu m. Comparison to interstellar ice analogs shows that the 7.24 mu m band can be well matched by the CH deformation mode of formic acid (HCOOH), while the 7.41 mu m band can be fitted both by the formate ion (HCOO(…