TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3934
SUBJECT: GRB 050906: Swift XRT upper limit
DATE:    05/09/06 19:59:02 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

C. Pagani (PSU/INAF-OAB), V. La Parola(INAF-IASF), D. N. Burrows (PSU) 
report on behalf of the Swift XRT team:

The Swift XRT has observed the field of GRB050906 for 6.0 ks.  There are 2 
faint serendipitous sources in 5.2 ks of data taken in photon-counting 
mode.  Source #1 is marginally detected (at a flux of roughly 8e-14 erg 
cm-2 s-1), while Source #2 is brighter.

The nearest X-ray source to the BAT position is source #1, which is 3.9 
arcmin from the on-board BAT position (Krimm et al. 2005, GCN 3926) and 6.3 
arcmin from the refined BAT position (Krimm et al., private 
communication).  No X-ray sources are found in the BAT error circle down to 
a 90% confidence upper limit of ~8e-14 erg cm-2 s-1.

No X-ray emission is detected from the position of the galaxy IC328 
reported by Levan et al. 2005 (GCN 3927).  The nearest X-ray source to the 
galaxy position is also Source #1, which is 4.6 arcmin away.

No X-ray emission is detected from the position of the radio source 
reported by Cameron and Frail 2005 (GCN 3933).  Source #1 is also closest 
to the reported radio source, at a distance of 3.7 arcmin.

No further observations are planned with the XRT.

This message can be cited.