Discovery of a 30-d period in the supergiant fast X-ray transient SAX J1818.6-1703
Hill, A. B.; Bird, A. J.; McBride, V. A.; Bazzano, A.; Sguera, V.; Shaw, S. E.; Watkins, H. J.
United Kingdom, Italy
Abstract
SAX J1818.6-1703 has been characterized as a supergiant fast X-ray transient system on the basis of several INTEGRAL/IBIS detections since the original BeppoSAX Wide Field Camera detection. Using IBIS/ISGRI, Swift/BAT and archival observations, we show that, in fact, SAX J1818.6-1703 exhibits emission on a period of 30 +/- 0.1 d, with a high degree of recurrence. SAX J1818.6-1703 is therefore the second supergiant fast X-ray transient shown to exhibit periodic outbursts, but with a considerably shorter period than the other known system, IGR J11215-5952.