[vsnet-grb-info 2067] GRB 050827: Swift XRT preliminary analysis results

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3906
SUBJECT: GRB 050827: Swift XRT preliminary analysis results
DATE:    05/09/01 08:29:17 GMT
FROM:    Milvia Capalbi at ISAC/ASDC  <capalbi at asdc.asi.it>

M. Capalbi (ASDC), G. Tagliaferri (INAF-OAB), P. Romano (INAF-OAB),
P. Boyd (GSFC-UMBC), W. Voges (MPE), D. N. Burrows (PSU)
and N. Gehrels (GSFC) report on behalf of the Swift XRT team:

We have analyzed 62 ks of Swift XRT data of GRB 050827 (Capalbi et al.,
GCN 3893) collected up to August 30, 2005 at 21:16:58 UT.

The XRT 0.3-10 keV light curve shows a temporal decay with a power
law index of -1.2 +/- 0.2 (90% confidence level), thus confirming
that the source suggested in the previous circular (Capalbi et al.,
GCN 3899) is the X-ray afterglow of GRB 050827.

A spectral fit to the data in the 0.3-10 keV band, gives a power law
photon index of  1.9 +/- 0.2 (90% confidence level) with an absorption
column density of 4.0 (-1.0, +1.5)E21 cm^-2 (90% confidence
level), slightly in excess of the Galactic value(1.95E21cm^-2).