[AAVSO-HEN] GRB 071112B: Swift-XRT preliminary analysis

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  7072
SUBJECT: GRB 071112B: Swift-XRT preliminary analysis
DATE:    07/11/13 00:45:21 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri at asdc.asi.it>

M. Perri, G. Stratta (ASDC), D.N. Burrows (PSU) report on behalf of the
Swift-XRT team:

The Swift-XRT began observing the field of the short hard GRB 071112B
(trigger=296503, Perri et al., GCN Circ. 7058) at 19:25:35 UT, about
62 minutes after the BAT trigger. In the first 2.1 ks of Photon Counting
mode data, no X-ray source is detected within the refined BAT error
circle (Fenimore et al., GCN Circ. 7071)

We estimate a 3-sigma upper limit on the count rate of ~5e-3 cts/s.
Assuming a power-law spectrum with photon index Gamma=2 and a Galactic
column density of 7.9e20 cm-2, this corresponds to an upper limit on the
observed flux of ~2e-13 ergs/cm2/s (0.3-10 keV)

This is an official product of the Swift XRT Team.