TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3528
SUBJECT: GRB 050607 - XRT refined data analysis
DATE:    05/06/07 16:56:15 GMT
FROM:    Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>

C.Pagani, D. Grupe, D. Burrows, J. Kennea, J. Racusin (PSU), and N Gehrels
(GSFC), on behalf of the Swift XRT team report:

We analyzed the XRT data of the first two orbits of GRB 050607
(Retter et al., GCN #3525). The observations started at 09:13:02 UT
(100 s after the BAT burst trigger).  Preliminary analysis of the data
obtained in the first 4.2ks of observations gives the following refined
coordinates for the X-ray afterglow:

Ra-2000:   20h 00m 42.6s
Dec-2000:  09d 08' 26.9"

The centroiding error is 6" radius (90%containment).
This position is about 5" from the optical afterglow position reported by
Rhoads (GCN #3527) and 3" from the previously reported XRT position (Retter
et al., GCN #3525).

The X-ray spectrum can be fitted with a single powerlaw with an X-ray
photon index=1.86+/-0.44. The fit is consistent with Galactic absorption
(NH=1.41e21 cm-2).

The lightcurve has a peak around 310sec after the burst trigger.

The source had a unabsorbed flux of 1.6e-12 ergs/s/cm2 at approximately one
hour after the burst and is decaying with a decay slope alpha=0.58+/-0.12.

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