Bibcode
den Hartog, P. R.; in't Zand, J. J. M.; Kuulkers, E.; Cornelisse, R.; Heise, J.; Bazzano, A.; Cocchi, M.; Natalucci, L.; Ubertini, P.
Bibliographical reference
Astronomy and Astrophysics, v.400, p.633-641 (2003)
Advertised on:
3
2003
Journal
Citations
24
Refereed citations
21
Description
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.