GCN Circular 14555
Subject
GRB 130502B: Swift-XRT refined Analysis
Date
2013-05-04T13:30:51Z (11 years ago)
From
Andrea Melandri at INAF-OAB <andrea.melandri@brera.inaf.it>
A. Melandri (INAF-OAB) and S. Immler (NASA/CRESST/GSFC) report on
behalf of the Swift-XRT team:
We have analysed 8.3 ks of XRT data for the Fermi/LAT-detected burst:
GRB 130502B (Kocevski et al. GCN Circ. 14532), from 55.1 ks to 101.8
ks after the Fermi/LAT trigger.
The object dectected in the first 3.4 ks of XRT data (Melandri &
Immler GCN Circ. 14540) is now clearly fading. The light curve can be
modelled with a power-law decay with a decay index of alpha=1.52
(+/-0.25).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.89 (+/-0.20). The best-
fitting absorption column is 1.73 (+0.78, -0.71) x 10^21 cm^-2, in
addition to the Galactic value of 1.1 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 4.3 x 10^-11 (6.3 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.1 x 10^21 cm^-2
Intrinsic column: 1.73 (+0.78, -0.71) x 10^20 cm^-2
Photon index: 1.89 (+0.21, -0.20)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020266.
This circular is an official product of the Swift-XRT team.