Search Publications
NaI and HI 3-D density distribution in the solar neighbourhood
Freire Ferrero, R.; Siebert, A.; Vergely, J. -L. +1 more
A study of the local interstellar medium (LISM) using a robust inversion method, similar to current tomography techniques, is applied to compiled data on neutral interstellar absorbers and Hipparcos parallaxes. We present here the 3-D distribution of two neutral species, NaI and HI. Our analysis enables us to obtain a reliable 3-D density distribu…
The complex iron line of NGC 5506
Piro, L.; Perola, G. C.; Fiore, F. +4 more
The bright Narrow Emission Line Galaxy, NGC 5506, has been observed simultaneously by XMM-Newton and BeppoSAX. The iron line is complex, with at least two components: one narrow and corresponding to neutral iron, the second one broad and corresponding to ionized iron. The latter line is equally well fitted by a truly broad line or by a blend of He…
Far-infrared mapping of the starburst galaxy NGC 253 with ISOPHOT
Lemke, D.; Radovich, M.; Kahanpää, J.
A 180 mu m map and strip maps at 120 and 180 mu m were obtained for the edge-on starburst galaxy
Optical spectroscopy and photometry of the neutron star RX J1856.5-3754
Kulkarni, S. R.; van Kerkwijk, M. H.
We present spectroscopy and imaging with the Very Large Telescope (VLT) of the neutron star
High-resolution spectroscopy of the low-mass X-ray binary EXO 0748-67
Kahn, S. M.; Brinkman, A. C.; den Herder, J. W. +2 more
We present initial results from observations of the low-mass X-ray binary
New constraints on the cosmic mid-infrared background using TeV gamma-ray astronomy
Lagache, G.; Puget, J. -L.; Renault, C. +1 more
Very high energy gamma-ray data obtained by CAT and HEGRA from the active galactic nucleus Mkn 501 are used to constrain the cosmic Mid-Infrared background. While the entire infrared and submillimeter spectrum shape based on models has been fixed and the density scaled as a whole in previous studies, recent measures on the low and high energy infr…
Spectroscopic monitoring of 10 new northern slowly pulsating B star candidates discovered from the HIPPARCOS mission
Mathias, P.; Aerts, C.; Cuypers, J. +4 more
A one-year follow-up campaign of high-resolution, high-signal-to-noise spectroscopy for 10 candidate slowly pulsating B stars, which were discovered from the HIPPARCOS astrometric mission, shows that all stars exhibit line-profile variability. From our data, and from the HIPPARCOS photometry, we conclude that all but one of the targets provide evi…
Screening the Hipparcos-based astrometric orbits of sub-stellar objects
Arenou, F.; Pourbaix, D.
The combination of Hipparcos astrometric data with the spectroscopic data of putative extrasolar planets seems to indicate that a significant fraction of these low-mass companions could be brown or M dwarfs (Han et al. \cite{Han-2001:a}). We show that this is due to the adopted reduction procedure, and consequently that the Hipparcos data do not r…
Stellar populations in NGC 5128 with the VLT: Evidence for recent star formation
Minniti, D.; Rejkuba, M.; Bedding, T. R. +1 more
We resolve stars of the nearest giant elliptical galaxy NGC 5128 using VLT with FORS1 and ISAAC. We construct deep U, V and Ks color-magnitude and color-color diagrams in two different halo fields (in the halo and in the north-eastern diffuse shell). In the outer, shell field, at ~ 14 kpc from the center of the galaxy, there is a signif…
The problem of the Pleiades distance. Constraints from Strömgren photometry of nearby field stars
Stello, D.; Nissen, P. E.
The discrepancy between the Pleiades cluster distance based on Hipparcos parallaxes and main sequence fitting is investigated on the basis of Strömgren photometry of F-type stars. Field stars with the same metallicity as the Pleiades have been selected from the m1 index and a technique has been developed to locate the ZAMS of these fiel…