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GCN Circular 15344

GRB 131014A: Swift-XRT refined Analysis
2013-10-16T11:06:55Z (11 years ago)
Kim Page at U.of Leicester <>
A. Amaral-Rogers, P.A. Evans & K.L. Page (U.Leicester) report on behalf of
the Swift-XRT team:

We have analysed 11 ks of XRT data for the Fermi/LAT-detected burst:
GRB 131014A,  from 44.1 ks to 173.4 ks after the  Fermi/LAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Fermi/LAT error circle.

The enhanced XRT position was given in GCN Circ. 15339 (Evans &

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.53 (+/-0.28).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+0.7, -0.6). The
best-fitting absorption column is  6.8 (+4.0, -3.0) x 10^21 cm^-2, in
excess of the Galactic value of 2.2 x 10^21 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.9 x 10^-11 (8.5 x 10^-11) erg
cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column:	     6.8 (+4.0, -3.0) x 10^21 cm^-2
Galactic foreground: 2.2 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:	     2.2 (+0.7, -0.6)

The results of the XRT-team automatic analysis are available at

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