TITLE:   GCN CIRCULAR
NUMBER:  23472
SUBJECT: GRB 181201A: Swift-XRT afterglow
DATE:    18/12/01 12:12:37 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF  <sandro.mereghetti@inaf.it>

F.Pintore, S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay),  C.Ferrigno,
E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC,
Versoix)
and J.Borkowski (CAMK, Torun) report:

Swift/XRT observed the position of GRB181201A on 1 December 2018 from 6:33
UT to 7:06 UT (GCN #23471), in PC mode.

The XRT data show that the X-ray source reported by Mereghetti et al. (GCN
Circ. n. 23471 ) is fading and has  an average spectrum well modelled by a
single absorbed powerlaw. The best-fit parameters are: column density of (6
+\- 2)x10^20 cm-2, consistent with the Galactic column density (5.2e20
cm-2, Willingale et al.2013),  photon index of 1.76 +\- 0.08. The average
0.3-10 keV absorbed flux is (1.06 +\- 0.06)x10^-10 erg cm-2 s-1.

The time decay is well modeled with a power law of index 1.2 +\- 0.1