GCN Circular 3519

subject: GRB 050603 - XRT data analysis of the first day

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

We analyzed the XRT data of the first day of observation of the GRB 
050603 (Retter
et al., GCN #3509). The observations started approximately 11 hours 
after the
burst (Racusin et al., GCN #3514).
Preliminary analysis of the data obtained so far (31 ks)
give the following refined coordinates:

Ra-2000:   02h 39m 56.8s
Dec-2000: -25d 10' 59.8"

The centroiding error is 6".
This position is about 7" off the X-ray position given in Racusin et al. 
(GCN
#3514) and 5" off the radio position (Cameron, GCN #3113) and the UVOT 
position
given in Brown et al. (GCN #3116).


The source had a flux of 2.2e-12 ergs/s/cm2 11 hours after the burst and is
decaying with a decay slope alpha=1.78+/-0.14.

The X-ray spectrum can be fitted with a single powerlaw with an X-ray 
spectral
slope beta=0.80+/-0.08. The fit is consistent with Galactic absorption 
(NH=2e20
1/cm2).

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