TITLE:   GCN CIRCULAR
NUMBER:  15431
SUBJECT: GRB 131018B: Further Swift-XRT observations.
DATE:    13/11/01 13:32:42 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), P. A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

We have analysed 6.7 ks of XRT data for the Fermi/LAT-detected burst GRB 131018B (Vianello et al., GCN 15357; Zhang, GCN 15360), from 1081.2 ks to 1100.0 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. The uncatalogued X-ray source reported in D'Avanzo et al. (GCN 15361) is not longer detected. The source count rate changed from 5.7e-3 +/- 1.8e-3 cts/s in the first epoch (D'Avanzo et al., GCN 15361) to a 3-sigma upper limit of 1.1e-3 cts/s. 
We can conclude that this source is likely the X-ray afterglow of GRB 131018B.

This circular is an official product of the Swift XRT team.