GCN Circular 45834

S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha
(GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss
(GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T.
Sakamoto (AGU) (i.e. the Swift-BAT team):

Using the data set from T-179 to T+200 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 261005B (trigger #1515414)
(Parsotan et al., GCN Circ. 45812
Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 255.322, 1.584 deg which is
   RA(J2000)  =  17h 01m 17.3s
   Dec(J2000) = +01d 35' 02.3"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The
partial coding was 93%.

The mask-weighted light curve shows a multi-peaked structure that starts at
~T0 and ends at ~T+100 s. The two main peaks occur at ~T+4 s and ~T+21 s,
respectively. T90 (15-350 keV) is 94.00 +- 20.10 sec (estimated error
including systematics).

The time-averaged spectrum from T+1.78 to T+106.78 sec is best fit by a
simple power-law model.  The power law index of the time-averaged spectrum
is 1.37 +- 0.27.  The fluence in the 15-150 keV band is 7.9 +- 1.3 x 10^-07
erg/cm2. The 1-sec peak photon flux measured from T+3.78 sec in the 15-150
keV band is 0.7 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90%
confidence level.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1515414