[vsnet-grb-info 17091] GRB 151006A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18409
SUBJECT: GRB 151006A: Swift-BAT refined analysis
DATE:    15/10/07 15:19:37 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien at nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),  N. Gehrels (GSFC),
D. Kocevski (NASA/GSFC/ORAU), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+800 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 151006A (trigger #657750)
(Kocevski, et al., GCN Circ. 18398).  The BAT ground-calculated position is
RA, Dec = 147.426, 70.508 deg which is
  RA(J2000)  =  09h 49m 42.3s
  Dec(J2000) = +70d 30' 30.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a FRED-like structure that starts at ~T-5 s,
peaks at ~ T+1 s, and ends at ~ T+310 s. T90 (15-350 keV) is 203.9 +- 41.6 sec
(estimated error including systematics).

The time-averaged spectrum from T-4.9 to T+311.2 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.56 +- 0.06.  The fluence in the 15-150 keV band is 6.9 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.49 sec in the 15-150 keV band
is 2.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/657750/BA/