[vsnet-grb-info 13637] GRB 130701A, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14959
SUBJECT: GRB 130701A, Swift-BAT refined analysis
DATE:    13/07/01 17:04:26 GMT
FROM:    Tilan Ukwatta at MSU  <tilan.ukwatta at gmail.com>

T. Sakamoto (AGU), 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), N. P. M. Kuin (UCL-MSSL),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+349 sec from the recent
telemetry downlink, we report further analysis of BAT
GRB 130701A (trigger #559482) (Kuin, et al., GCN Circ. 14953).
The BAT ground-calculated position is RA, Dec = 357.224, 36.100 deg
which is
   RA(J2000)  =  23h 48m 53.7s
   Dec(J2000) = +36d 05' 58.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90%
containment). The partial coding was 28%.

BAT mask-weighted light curve shows overlapping two-peak structure
starting from T-1 sec with first peak around T+1 sec and
second peak around T+3 sec. The episode ends around T+5 sec.
T90 (15-350 keV) is 4.38 +- 0.25 sec (estimated error
including systematics).

The time-averaged spectrum from T-1.14 to T+5.35 sec is best
fit by a power law with an exponential cutoff.  This fit gives a
photon index 0.90 +- 0.21, and Epeak of 89.2 +- 12.4 keV
(chi squared 40.06 for 56 d.o.f.).  For this model the total fluence
in the 15-150 keV band is 4.4 +- 0.1 x 10^-06 erg/cm2 and the 1-sec
peak flux measured from T+0.06 sec in the 15-150 keV band is
17.1 +- 0.7 ph/cm2/sec.  A fit to a simple power law gives a
photon index of 1.58 +- 0.05 (chi squared 76.39 for 57 d.o.f.).
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/559482/BA/