[vsnet-grb-info 4091] GRB061126: update on the Swift-XRT afterglow light curve

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5900
SUBJECT: GRB061126: update on the Swift-XRT afterglow light curve
DATE:    06/12/06 09:01:40 GMT
FROM:    Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti at ifc.inaf.it>

B. Sbarufatti (INAF IASF Pa), G. Cusumano (INAF IASF Pa), T. Mineo (INAF 
IASF Pa), V. Mangano (INAF IASF Pa) report on behalf of the SWIFT team

We have analyzed the afterglow light curve of GRB061126 (GCN 5854, 
Sbarufatti et  al.) observed with XRT.
The source is decaying as a simple power law with slope alpha=-1.31 +/- 
0.01 since its first detection with XRT up to T+76ks.
We do not find evidence of the possible jet break reported by Kann et 
al. (GCN 5875) - but not detected by Rol et al. (GCN 5876) - at 1.8 days 
after the trigger.
A  tentative fit with a broken powerlaw, albeit very poorly constrained, 
  showed a marginal compatibility with a flattening of the light curve 
after T+1E5s, as opposed with the steepening expected from a jet break.

XRT observation of the afterglow (which shows a count rate 1.5E-3 c/s at 
T+76 ks)are still ongoing.

This circular is an official product of the Swift XRT Team.