Search Publications
Slow magnetoacoustic waves in coronal loops: EIT and TRACE
Berghmans, D.; Poedts, S.; Hochedez, J. F. +3 more
On May 13, 1998 the EIT (Extreme ultraviolet Imaging Telescope) on board of SoHO (Solar and Heliospheric Observatory) and TRACE (Transition Region And Coronal Explorer) instruments produced simultaneous high cadence image sequences of the same active region (AR 8218). TRACE achieved a 25 s cadence in the Fe Ix (171 Å) bandpass while EIT achieved a…
The effective temperatures of carbon-rich stars
Bergeat, J.; Knapik, A.; Rutily, B.
We evaluate effective temperatures of 390 carbon-rich stars. The interstellar extinction on their lines of sights was determined and circumstellar contributions derived. The intrinsic (dereddened) spectral energy distributions (SEDs) are classified into 14 photometric groups (HCi, CVj and SCV with i=0,5 and j=1,7). The new sc…
On OH line formation and oxygen abundances in metal-poor stars
Asplund, M.; García Pérez, A. E.
The formation of the UV OH spectral lines has been investigated for a range of stellar parameters in the light of 3D hydrodynamical model atmospheres. The low atmospheric temperatures encountered at low metallicities compared with the radiative equilibrium values enforced in classical 1D hydrostatic model atmospheres have a profound impact on the …
XMM-Newton observation of the Coma Galaxy cluster. The temperature structure in the central region
Altieri, B.; Aghanim, N.; Arnaud, M. +8 more
We present a temperature map and a temperature profile of the central part (r < 20' or 1/4 virial radius) of the Coma cluster. We combined 5 overlapping pointings made with XMM/EPIC/MOS and extracted spectra in boxes of 3.5'x3.5'. The temperature distribution around the two central galaxies is remarkably homogeneous (r<10'), contrary to prev…
The XMM-Newton Serendipitous Survey. I. The role of XMM-Newton Survey Science Centre
Valtchanov, I.; Pietsch, W.; Read, A. M. +46 more
This paper describes the performance of XMM-Newton for serendipitous surveys and summarises the scope and potential of the XMM-Newton Serendipitous Survey. The role of the Survey Science Centre (SSC) in the XMM-Newton project is outlined. The SSC's follow-up and identification programme for the XMM-Newton serendipitous survey is described together…
Exploring brown dwarf disks
Testi, L.; Natta, A.
We discuss the spectral energy distribution of three very low mass objects in Chamaeleon I for which ground-based spectroscopy and photometry as well as ISO measurements in the mid-infrared are available (Comerón et al. \cite{CNK00}; Persi et al. \cite{Pea00}). One of these stars (\1) is a bona-fide brown dwarf, with mass 0.04-0.05 M_sun. We show …
The XMM-Newton view of stellar coronae: X-ray spectroscopy of the corona of AB Doradus
Haberl, F.; Mewe, R.; Audard, M. +6 more
We report results of deep X-ray observations of
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…
FIRBACK: III. Catalog, source counts, and cosmological implications of the 170 mu m ISO
Elbaz, D.; Cesarsky, C.; Bouchet, F. R. +17 more
The FIRBACK (Far Infrared BACKground) survey is one of the deepest imaging surveys carried out at 170 mu m with ISOPHOT onboard ISO, and is aimed at the study of the structure of the Cosmic Far Infrared Background. This paper provides the analysis of resolved sources. After a validated process of data reduction and calibration, we perform intensiv…
Stellar encounters with the solar system
Lestrade, J. -F.; Latham, D. W.; Paredes, J. M. +5 more
We continue our search, based on Hipparcos data, for stars which have encountered or will encounter the solar system (García-Sánchez et al. \cite{Garcia}). Hipparcos parallax and proper motion data are combined with ground-based radial velocity measurements to obtain the trajectories of stars relative to the solar system. We have integrated all tr…