Volume 400, Number 2, March III 2003
|Page(s)||633 - 641|
|Section||Stellar structure and evolution|
|Published online||03 March 2003|
Burst-properties as a function of mass accretion rate in GX 3+1
Astronomical Institute, Utrecht University, PO Box 80000, 3508 TA Utrecht, The Netherlands
2 SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
3 Istituto Astrofisica Spaziale e Fisica Cosmica, CNR, via Fosso del Cavaliere 100, 00133 Roma, Italy
Corresponding author: P. R. den Hartog, P.R.den.Hartog@sron.nl
Accepted: 9 January 2003
GX 3+1 is a low-mass X-ray binary that is persistently bright since its discovery in 1964. It was found to be an X-ray burster twenty years ago proving that the compact object in this system is a neutron star. The burst rate is so low that only 18 bursts were reported prior to 1996. The Wide Field Cameras on BeppoSAX have, through a dedicated monitoring program on the Galactic center region, increased the number of X-ray bursts from GX 3+1 by 61. Since GX 3+1 exhibits a slow (order of years) modulation in the persistent flux of about 50%, these observations opens up the unique possibility to study burst properties as a function of mass accretion rate for very low burst rates. This is the first time that bursts are detected from GX 3+1 in the high state. From the analysis we learn that all bursts are short with e-folding decay times smaller than 10 s. Therefore, all bursts are due to unstable helium burning. Furthermore, the burst rate drops sixfold in a fairly narrow range of 2–20 keV flux; we discuss possible origins for this.
Key words: accretion, accretion discs / binaries: close / stars: individual: GX 3+1 / stars: neutron / X-rays: bursts
© ESO, 2003
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.