[vsnet-grb-info 8742] GRB091202: Swift-XRT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10243
SUBJECT: GRB091202: Swift-XRT refined analysis
DATE:    09/12/03 20:13:43 GMT
FROM:    Loredana Vetere at PSU  <vetere at astro.psu.edu>

L. Vetere (PSU) reports on behalf of the Swift-XRT team:

We have analysed 5.6 ks of XRT data for GRB 091202 (Mereghetti et al.
GCN Circ. 10234) from 2364 s to 26.9 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Vetere et al. (GCN. Circ 10239).

The light curve is decaying but we do not have enough data to estimate
the decay slope and no more observations are planned at this time.

The spectrum comprises only 27 photons, but it can be fitted with an  
absorbed
power-law with a photon spectral index of 2.2 (+0.9 -0.8).  The best- 
fitting
absorption column is 2.0 (+2.9, -1.2) x 10^21 cm^-2, in excess of the  
Galactic
value of 3.9 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 4.2 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020123.

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