TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3560
SUBJECT: GRB 050701: Refined XRT analysis
DATE:    05/07/01 22:38:03 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

C. Hurkett, J. P. Osborne, K. L. Page, M. R. Goad, A. A. Wells
(U. Leicester), J. L. Racusin, D. N. Burrows, D. C. Morris, D. Grupe,
M. Chester (PSU), F. Marshall and N. Gehrels (GSFC)  report on behalf of
the Swift XRT team:

We have analyzed the Swift XRT data from the first four orbits of GRB
050701 ToO (Racusin et al., GCN3557; Krimm et al., GCN 3558).  The X-ray 
source is clearly fading during this time period, indicating that it is the 
GRB afterglow.  The refined
coordinates for the X-ray afterglow are:

RA(J2000) = 15h 09m 01.8s,  Dec(J2000) = -59:24:50.1

The estimated uncertainty is 6 arcseconds radius (90% containment).

A preliminary spectral fit to all of the PC data gives a spectral power
law photon index of 1.8 +/- 0.5 in the [0.2-10] keV band, assuming
Galactic absorption (5.6E20cm^-2). The average estimated flux for this
model in the 2.0-10.0 keV range is approximately 1.9E-12 ergs cm-2 s-1 at
6770s after the trigger time.  A preliminary estimate of the X-ray decay 
power-law index is alpha = -0.66.