[vsnet-grb-info 4048] GRB 061126: Swift-XRT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5862
SUBJECT: GRB 061126: Swift-XRT refined analysis
DATE:    06/11/26 19:35:02 GMT
FROM:    Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti at ifc.inaf.it>

B. Sbarufatti (INAF IASF-Pa), V. Mangano (INAF IASF-Pa), C. Guidorzi  
(INAF OAB)
and D. N. Burrows, report on behalf of the Swift XRT team:

We have analyzed the first 3 orbits of Swift-XRT data obtained for  
GRB 061126
(trigger=240766, GCN 5854). The data consist of 240 s in Windowed  
Timing (WT) mode,
starting 1603 seconds after the trigger followed by 6 ks in Photon  
Counting (PC) mode.

Using the PC data we obtain a refined position of:

RA(J2000) =  05h 46m 24.5s
Dec(J2000)= +64d 12m 37.6s

with an estimated uncertainty radius of 3.5 arcsec (90% containment).
This location is 1.62 arcsec from the first XRT position (GCN 5855)  
and 0.95 arcsec
from the UVOT position (GCN 5856).

The light-curve shows a power-law decay with slope alpha=1.3 +/- 0.03  
up to the end of
the third orbit.

The PC spectrum  can be modeled with an absorbed power-law of photon  
index
Gamma = 2.01 +/- 0.09 and NH= (2.7 +/- 0.3)E21 cm^-2 in excess with  
respect to the
galactic absorption of 1.0E21 cm^-2. The average unabsorbed flux is
7.7E-11 ergs cm^-2 s^-1.

If decaying at the present rate, the source will reach a flux level of
1.7e-12 erg cm^-2 s^-1 (2.6E-2 c/s) at 24 h after the trigger.


All errors are quoted at 90% confidence level.

This circular is an official product of the Swift-XRT team.