INTEGRAL detection of the faint X-ray transient SAX J1806.5-2215
ATel #8222; V. Sguera (INAF-IASF Bologna, Italy), L. Sidoli (INAF-IASF Milano, Italy), M. Fiocchi, A. Bazzano, P. Ubertini (INAF-IAPS Roma, Italy), A. Paizis (INAF-IASF Milano, Italy), E. Kuulkers (ESA/ESAC, Spain)
on 29 Oct 2015; 12:48 UT
Credential Certification: Adamantia Paizis (firstname.lastname@example.org)
Subjects: Neutron Star, Transient
During recent INTEGRAL Galactic Plane Scan observations performed between 2015-10-26 06:57 and 2015-10-27 02:53 (UTC), IBIS/ISGRI detected hard X-ray activity from the faint X-ray transient SAX J1806.5-2215. The 22-60 keV IBIS/ISGRI significance level is about 7 sigma (effective exposure of about 5 ks), the spectrum is well fitted by a power law model with photon index equal to 2.3+/-0.8 and average flux of 2.4x10^-10 erg/cm2/s (22-60 keV). The source was never in the field of view of the JEM-X monitor. The last INTEGRAL detection reported from the source dates back to March 2012 (ATel #4017) when the measured 20-80 keV flux was 1.6x10^-10 erg/cm2/s. For comparison, we derived a 20-80 keV flux from the current detection of 3.2x10^-10 erg/cm2/s. It is possible that the current detection is part of the same outburst which started in Feb 2011 (ATel #3193).