TITLE:   GCN CIRCULAR
NUMBER:  5758
SUBJECT: GRB061025: Swift XRT refined analysis
DATE:    06/10/26 15:07:08 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

T. Mineo (IASF-Pa), V. Mangano (IASF-Pa), G. Cusumano (IASF-Pa),
and B. Sbarufatti (IASF-Pa) report on behalf of the Swift XRT team:

We analysed the first 9 ks of Swift-XRT data obtained in PC mode for
GRB061025 detected by INTEGRAL (Mereghetti et al. 2006, GCN 5751).

The light-curve shows a first shallow decay (alpha1=0.7+/-0.8) up
to a break at t_break=20+/-4 ks, followed by a steeper decay
(alpha2=3.4+/-1.2). If decaying at the present rate the source
will reach a level of 1E-4 c/s at 24 hr since the trigger.

The average spectrum can be modelled with a power-law of photon
index Gamma = 1.7 � 0.4, with an absorbing column consistent with
the Galactic value of 5E20 cm-2. The average unabsorbed flux is
(4.3 �0.8)E-13 ergs cm-2 s-1, corresponding to a count rate of
5.3E-3 c/s.
All errors are quoted at 90% confidence level.

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