[vsnet-grb-info 6764] GRB 081012, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8363
SUBJECT: GRB 081012, Swift-BAT refined analysis
DATE:    08/10/12 16:34:59 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

G. Sato (ISAS), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), M. C. Stroh (PSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081012 (trigger #331475)
(Stroh, et al., GCN Circ. 8361).  The BAT ground-calculated position is
RA, Dec = 30.184, -17.627 deg which is 
   RA(J2000)  =  02h 00m 44.1s 
   Dec(J2000) = -17d 37' 36.2" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.
 
The mask-weighted light curve shows a roughly symmetrical peak starting 
at ~T-20 sec, peaking at ~T+1 sec, and ending at ~T+20 sec.  There is
a possibility of earlier emission at ~T-50 sec.
T90 (15-350 keV) is 29 +- 4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-23.1 to T+8.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.03 +- 0.18.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.93 sec in the 15-150 keV band
is 1.0 +- 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/331475/BA/