Volume 365, Number 1, January 2001
First Results from XMM-Newton
|Page(s)||L282 - L287|
|Published online||15 January 2001|
The eclipsing bursting X-ray binary EXO 0748-676 revisited by XMM-Newton
Service d'Astrophysique, DSM/DAPNIA/SAp, CE Saclay, 91191 Gif-sur-Yvette Cedex, France
2 Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
3 Department of Physics & Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK
4 Institut für Astronomie und Astrophysik - Astronomie, University of Tübingen, Waldhäuser Strasse 64, 72076 Tübingen, Germany
Corresponding author: J. M. Bonnet-Bidaud, firstname.lastname@example.org
Accepted: 8 November 2000
The bright eclipsing and bursting low-mass X-ray binary EXO 0748-676 has been observed at several occasions by XMM-Newton during the initial calibration and performance verification (CAL/PV) phase. We present here the results obtained from observations with the EPIC cameras. Apart from several type-I X-ray bursts, the source shows a high degree of variability with the presence of soft flares. The wide energy coverage and high sensitivity of XMM-Newton allows for the first time a detailed description of the spectral variability. The source is found to be the superposition of a central (~2 108 cm) Comptonized emission, most probably a corona surrounding the inner edge of an accretion disk, associated with a more extended (~3 1010 cm) thermal halo at a typical temperature of ~0.6 keV with an indication of non-solar abundances. Most of the variations of the source can be accounted for by a variable absorption affecting only the central comptonized component and reaching up to NH cm-2. The characteristics of the surrounding halo are found compatible with an irradiated atmosphere of an accretion disc which intercepts the central emission due to the system high inclination.
Key words: stars: individual (EXO 0748-676/UY Vol) / binaries: eclipsing / X-rays: stars / accretion: accretion disc
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.