The Neil Gehrels Swift Observatory

XRT Message

XRT was in an anomalous state between 00:22 UT June 4th, 2014, and 17:58 UT on June 10th. During this time, data taken in Windowed Timing mode are indistinguishable from data taken in normal operations, and are safe to use. In Photon Counting mode, the data were not collected in the normal manner (there was no on-board bias subtraction, and the on-board low-energy threshold was raised to 0.5 keV), and the calibration is unverified. These data should not be used for spectroscopy or photometry, but positions derived from these data are not expected to be degraded compared to normal operations. We note that for some sequences no scientific data were collected as a consequence of the recovery operations. Information regarding the anomaly has been reported in GCN Circulars 16349, 16356, and 16378.