Swift J181723.1-164300 has entered quiescence
ATel #10624; J. A. Kennea (PSU)
on 8 Aug 2017; 15:59 UT
Credential Certification: Jamie A. Kennea (kennea@astro.psu.edu)
Subjects: X-ray, Binary, Neutron Star, Transient
Referred to by ATel #: 10665
On August 6th, 2017 and August 7th, 2017, Swift XRT performed observations of the field containing the new transient source Swift J181723.1-164300 (GCN #21369, ATel #10612), in Windowed Timing (WT) and Photon Counting (PC) mode respectively, for approximately 3ks each. In both observations, there was no significant detection of Swift J181723.1-164300, we find a 3-sigma upper limit XRT count rate of 7.4x10-3 XRT count/s.
In the previous Swift observation was taken on August 2nd, 2017, utilizing WT mode and a 5ks exposure, J181723.1-164300 was well detected, at a count rate of 1.91 +/- 0.15 XRT count/s. The spectrum was well described by an absorbed power-law model, with photon index = 1.7 +/- 0.2, and a flux (uncorrected for absorption) of 1.3 x 10-10 erg/s/cm2.
Assuming the same spectral model, the upper limit on the flux for the PC mode observation of August 7th, 2017 is 10-12 erg/s/cm2 (0.5 - 10 keV).
Given its non-detection in Swift observations taken on two consecutive days, we conclude that Swift J181723.1-164300 has entered quiescence.
