[vsnet-grb-info 14110] GRB 131031A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15424
SUBJECT: GRB 131031A: Swift-XRT observations
DATE:    13/11/01 06:36:03 GMT
FROM:    Kim Page at U.of Leicester  <klp5 at leicester.ac.uk>

B.P. Gompertz and K.L. Page (U. Leicester)  report on behalf of the
Swift-XRT team:

We have analysed 3.7 ks of XRT data for the Swift/BAT-detected burst:
GRB 131031A,  from 39.7 ks to 52.0 ks after the  Swift/BAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Swift/BAT error circle. Using 1649 s of PC mode
data and 1 UVOT images, we find an enhanced XRT position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 29.61022, -1.57882 which is equivalent to:

RA (J2000): 01h 58m 26.45s
Dec(J2000): -01d 34' 43.7"

with an uncertainty of 4.7 arcsec (radius, 90% confidence). This
position is 91 arcsec from the Swift/BAT position.  The source has a
mean count rate of 8.8e-03 ct/sec; we cannot determine at the present
time whether it is fading.


The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020317.

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