[vsnet-grb-info 13354] Swift XRT observation of GRB 130518B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14690
SUBJECT: Swift XRT observation of GRB 130518B 
DATE:    13/05/21 19:24:38 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti at brera.inaf.it>

Boris Sbarufatti (INAF-OAB/PSU) reports on behalf of the Swift XRT team

We have analysed 4.2 ks of XRT data for GRB 130518B (Cummings GCN Circ.
14862), from 184.0 ks to 196.1 ks after the BAT trigger. The data are all
in Photon Counting (PC) mode. No bright X-ray afterglow is detected inside
the refined BAT error circle. The 3sigma upper limit is of 4.3 x 10^-3
cts/s.

This corresponds to an observed 0.3-10 keV flux of 1.6 x 10^-13 erg/cm2/s
(assuming a typical GRB spectrum with photon spectral index of 2). If we
consider the Galactic absorption in this direction (3.5 x 10^20 cm^-2;
Kalberla et al. 2005) this corresponds to an unabsorbed flux of 1.8 x
10^-13 erg/cm2/s.