GCN Circular 15693
Subject
GRB 140103A: Swift XRT afterglow confirmation
Event
Date
2014-01-06T19:17:38Z (13 years ago)
From
Vanessa Mangano at PSU <vxm22@psu.edu>
V. Mangano (PSU) reports on behalf of the Swift-XRT team:
We have analysed 6.9 ks of XRT data for GRB 140103A (Mangano et al.
GCN Circ. 15656), from 153 s to 59.7 ks after the BAT trigger. The
data comprise 2.6 ks in Windowed Timing (WT) mode (the first 7 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode.
We confirm that the X-ray source reported in Mangano et al. GCN Circ.
15666 is the afterglow of GRB 140103A. Its light curve can now be
modelled with an initial power-law decay with an index of
alpha=0.18 (+0.17, -0.19), followed by a break at T+3221 s to
an alpha of 1.18 (+0.51, -0.28).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.6 (+0.5, -0.4). The
best-fitting absorption column is 2.5 (+1.9, -1.3) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 2.7 x 10^-11 (6.1 x 10^-11) erg
cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
Total column: 2.5 (+1.9, -1.3) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: 3.0 sigma
Photon index: 2.6 (+0.5, -0.4)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00582773.
This circular is an official product of the Swift-XRT team.