[vsnet-grb-info 5393] GRB 071112B, Swift-BAT partial refined analysis of the SHB

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7071
SUBJECT: GRB 071112B, Swift-BAT partial refined analysis of the SHB
DATE:    07/11/13 00:06:15 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

E. Fenimore (LANL), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), M. Perri (ASDC),
T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-120 to T+182 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 071112 (trigger #296503)
(Perri, et al., GCN Circ. 7058).  The BAT ground-calculated position is
RA, Dec = 260.213, -80.884 deg, which is 
   RA(J2000)  =  17h 20m 51.0s 
   Dec(J2000) = -80d 53' 02" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.
 
The mask-weighted light curve shows two separated narrow peaks.  The first
starts at T-0.7 sec and has a total width of ~64 msec.  The second
starts at T+0.0 sec, peaks at T+0.1 sec, and ends at 0.3 sec.
T90 (15-350 keV) is 0.30 +- 0.05 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.0 to T+0.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.69 +- 0.34.  The fluence in the 15-150 keV band is 4.8 +- 0.9 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.38 sec in the 15-150 keV band
is 1.3 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 

The automated script processing has generated fluence and spectral numbers
for the second peak only.  Since there seems to be urgent need in the 
community, we are pushing this circular out the door quickly so that at
least these partial (second peak only) values are available to the 
follow-up community.  By eye, the first peak appears to have a fluence
one third that of the second peak.  Also by eye, there appears to be no
extended emission for this SHB out to at least T+180 sec and to a flux
level ~0.007 counts/cm2/sec.