TITLE:   GCN CIRCULAR
NUMBER:  38364
SUBJECT: GRB 241127A: Swift-XRT refined Analysis
DATE:    24/11/28 11:07:18 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A. Melandri (INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), D.N.
Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans report on
behalf of the Swift-XRT team:

We have analysed 5.0 ks of XRT data for GRB 241127A, from 443 s to 27.9
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.66 (+0.05, -0.06).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.97 (+0.18, -0.17). The
best-fitting absorption column is  8.0 (+4.5, -3.9) x 10^20 cm^-2, in
excess of the Galactic value of 2.7 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (4.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     8.0 (+4.5, -3.9) x 10^20 cm^-2
Galactic foreground: 2.7 x 10^20 cm^-2
Excess significance: 2.2 sigma
Photon index:	     1.97 (+0.18, -0.17)


The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01270788.

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