GCN Circular 7079

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

We have analysed the first 7 orbits of Swift-XRT data obtained
for GRB 071112C (Perri et al. GCN Circ.7059
Not found
 
 
), totaling 281 s
of Windowed Timing (WT) data and 29.1 ks of Photon Counting (PC)
data.

Using 625 s of overlapping XRT Photon Counting mode and UVOT
V-band data, we find an astrometrically corrected X-ray position
(using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue):
RA,Dec =39.21220, 28.37102 which is equivalent to:

RA (J2000):  02 36 50.93
Dec (J2000): +28 22 15.7

with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This is 1.0 arcsec from the previous XRT position, 0.7 arcmin
from the BAT position and 1.0 arcsec from the UVOT position
(Perri et al, GCN Circ. 7059
Not found
 
 
).

The bright X-ray light-curve can be fit by a simple power-law,
with a decay index of 1.35 +/- 0.1.
Between about 400s and 1100s from the trigger, the data deviate
from the model, possibly pointing out a smooth re-brightening.

The WT data (91-372 seconds from trigger) can be modeled as an
absorbed power-law, with photon index of 1.7 +/- 0.1 and a total
absorbing column density consistent with the Galactic value of
NH=7.4e20 cm^-2 (Dickey & Lockmann 1990).
The 0.3-10 keV observed (unabsorbed) flux during this time is
4.4e-10(4.9e-10) erg cm^-2 s^-1.

Assuming the source continues to decay with the same decay
index of 1.35,we predict an XRT count rate of 3.0e-3 counts/s
at T+24 hours, which corresponds to an 0.3-10.0 keV observed
flux of 1.2e-13 ergs cm^-2 s^-1.

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