Search Publications
Dust in active nuclei. I. Evidence for ``anomalous'' properties
Maiolino, R.; Marconi, A.; Oliva, E. +5 more
We present observational evidences that dust in the circumnuclear region of AGNs has different properties than in the Galactic diffuse interstellar medium. By comparing the reddening of optical and infrared broad lines and the X-ray absorbing column density we find that the EB-V/N_H ratio is nearly always lower than Galactic by a factor…
Abundant molecular gas in tidal dwarf galaxies: On-going galaxy formation
Duc, P. -A.; Braine, J.; Charmandaris, V. +4 more
We investigate the process of galaxy formation as can be observed in the only currently forming galaxies - the so-called Tidal Dwarf Galaxies, hereafter TDGs - through observations of the molecular gas detected via its CO (Carbon Monoxide) emission. These objects are formed of material torn off of the outer parts of a spiral disk due to tidal forc…
HST/NICMOS2 coronagraphic observations of the circumstellar environment of three old PMS stars: HD 100546, SAO 206462 and MWC 480
Ménard, F.; Mouillet, D.; Augereau, J. C. +1 more
The close environment of four old Pre-Main Sequence stars has been observed thanks to the coronagraphic mode of the HST/NICMOS2 camera at lambda =1.6 mu m. In the course of this program, a circumstellar annulus around HD 141569 was detected and has already been presented in Augereau et al. (\cite{aug99b}b). In this paper, we report the detection o…
The M 31 double nucleus probed with OASIS. A natural vec m = 1 mode?
Combes, F.; Copin, Y.; Emsellem, E. +3 more
We present observations with the adaptive optics assisted integral field spectrograph OASIS of the M 31 double nucleus in the spectral domain around the Calcium triplet at a spatial resolution better than 0farcs5 FWHM. These data are used to derive the two-dimensional stellar kinematics within the central 2 arcsec. Archival WFPC2/HST images in the…
Asymmetries in the HD 141569 circumstellar disk
Ménard, F.; Mouillet, D.; Augereau, J. C. +1 more
We present HST/STIS coronagraphic observations of the disk around HD 141569. The data, with a spatial resolution and signal to noise higher than those previously obtained with HST/NICMOS2 allow a more detailed insight in the system. They reveal a very structured system, in which two ring-like structures at distances =~ 200 and 325 AU from the star…
Structure and physical properties of the rapidly evolving dusty envelope of IRC +10 216 reconstructed by detailed two-dimensional radiative transfer modeling
Weigelt, G.; Men'shchikov, A. B.; Balega, Y. +2 more
We present the first detailed, two-dimensional radiative transfer model of the dusty envelope around the carbon star
Mid-infrared imaging and spectroscopy of the enigmatic cocoon stars in the Quintuplet Cluster
Blommaert, J. A. D. L.; Moneti, A.; Najarro, F. +2 more
In an attempt to determine the nature of the enigmatic cocoon stars in the Quintuplet Cluster, we have obtained mid-infrared imaging and spectrophotometry of the cluster, using the CAM and SWS instruments on ISO, using SpectroCam-10 on the Palomar 5 m telescope, and NICMOS on HST. The spectra show smooth continua with various dust and ice absorpti…
Mid-Infrared observations of NGC 1068 with the Infrared Space Observatory
Le Floc'h, E.; Cesarsky, C.; Sauvage, M. +5 more
We report on Mid-Infrared (MIR) observations of the Seyfert 2 galaxy NGC 1068, obtained with ISOCAM in low-resolution spectro-imaging mode. The spatial resolution ( ~ 5 arcsec) allows us to disentangle the circumnuclear starburst regions from the emission of the active galactic nucleus (AGN). The global spatial distribution of the Unidentified Inf…
HST optical spectral index map of the jet of 3C 273
Meisenheimer, K.; Jester, S.; Röser, H. -J. +2 more
We present HST images at 622 nm and 300 nm of the jet in 3C 273 and determine the run of the optical spectral index at 0\farcs2 along the jet. The smoothness of spectral index changes shows that the physical conditions are varying smoothly across the jet. There is no correlation between the optical flux and spectral index, as would be expected for…
Local clouds: Ionization, temperatures, electron densities and interfaces, from GHRS and IMAPS spectra of epsilon Canis Majoris
Jenkins, E. B.; Gry, C.
The composition and physical properties of several local clouds, including the Local Interstellar Cloud (LIC) in which the Sun is embedded, are derived from absorption features in the UV spectrum of the star epsilon CMa. We derive temperatures and densities for three components by combining our interpretations of the ionization balance of magnesiu…