Search Publications
The stellar content of soft X-ray surveys. II. Cross-correlation of the ROSAT All-Sky Survey with the Tycho and Hipparcos catalogs
Schmitt, J. H. M. M.; Motch, C.; Guillout, P. +3 more
We present the result of the cross-correlation of the ROSAT All-Sky Survey with the Tycho and Hipparcos catalogs. The constructed RASS - Tycho (RasTyc) and RASS - Hipparcos (RasHip) samples respectively consist of 13 875 and 6 200 matches and represent the largest and most comprehensive samples of stellar X-ray sources constructed so far. The X-ra…
Globular clusters in NGC 5128
Côté, P.; Holland, S.; Hesser, J. E.
We used the Wide Field Planetary Camera 2 aboard the Hubble Space Telescope to search for globular clusters in the inner regions of the nearby giant elliptical galaxy
A very cold disc of dust around the G0V star HD 207129
Kessler, M. F.; Siebenmorgen, R.; Bouchet, P. +9 more
We present ISO observations made between 2.5 and 180 mu m of the nearby G0V dwarf HD 207129 taken as part of a large survey of nearby main-sequence stars in search of debris discs. HD 207129 emits radiation in excess of the photospheric flux density between at least 60 and 180 mu m. The infrared excess is explained by a disc of cold dust particles…
Interstellar C_2 absorption lines towards CH+ forming regions
Gredel, R.
Interstellar C_2 absorption line observations towards the southern OB associations NGC 2439, Vela OB1, and Cen OB1 are used to infer gaskinetic temperatures Tkin and densities nc towards lines of sight with previously determined large CH and CH+ column densities. Towards NGC 2439, the material is characterised by t…
The effects of opacity in the transition region of YZ CMi
Mathioudakis, M.; Keenan, F. P.; Phillips, K. J. H. +2 more
It has generally been assumed that the emission from the upper atmosphere of late-type stars is optically thin. In the present paper we use the Si IV and C IV resonance lines to investigate this assumption for the active dMe star YZ CMi. The significant deviations of the line ratios from their optically thin values, demonstrate that opacity can be…
Mid-infrared and far-ultraviolet observations of the star-forming ring of M 31
Sauvage, M.; Pagani, L.; Lequeux, J. +4 more
We present mid-IR images of a 15\arcminx15' field in the south-west part of the Andromeda galaxy M 31 obtained with the ISOCAM camera (6'' pixels) on board ISO. These broad-band images complement spectro-imaging observations of smaller fields (Cesarsky et al. \cite{Cesarsky98}). We also present a 20'' resolution far-UV image of a larger field at 2…
Element mixing in the Cassiopeia A supernova
Lagage, P. O.; Cesarsky, C. J.; Douvion, T.
Thanks to mid-infrared observations, we provide new clues to the element mixing during a supernova explosion by probing the mixing between three adjacent layers: the oxygen burning products layer (sulfur, argon,...), the silicate layer and the neon layer. The silicate and neon layers are both contaminated by sulfur and argon in a macroscopic way, …
SW Ursae Majoris, CU Velorum and AH Mensae: three more accreting white dwarfs unveiled?
Gänsicke, B. T.; Koester, D.
We present IUE spectroscopy of the three cataclysmic variables SW UMa, CU Vel, and AH Men. In all three systems, a broad Lyalpha absorption profile is observed. In the two short-period dwarf novae SW UMa and CU Vel, the SWP flux is interpreted as photospheric emission from white dwarfs with effective temperatures of 16 000 K and 18 500 K, respecti…
IRAS 04296+3429: a 21 MU M source with a very strong 30 MU M emission band
Henning, Th.; Szczerba, R.; Cox, P. +2 more
We report the detection of the 30 mu m emission feature from the C-rich post-Asymptotic Giant Branch (post-AGB) star IRAS 04296+3429 based on ISO SWS observations. ISO data show that there is a clear substructure in the 30 mu m feature in the form of a plateau which extends from 26 to 27 mu m. This is confirmed by the ISO SWS data for another post…
The mass function of M 4 from near IR and optical HST observations
Paresce, Francesco; de Marchi, Guido; Pulone, Luigi
Deep images of the galactic globular cluster M 4 taken at various locations with the NIC 3 and the WFPC 2 cameras on HST were used to derive detailed local optical and near IR luminosity functions. White dwarfs have been detected for the first time on a color sequence at constant luminosity in the F110W band. Transformation of the observed luminos…