GCN Circular 15234

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

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130919A (trigger #571271)
(Krimm, et al., GCN Circ. 15232
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 207.281, -10.353 deg which is
    RA(J2000)  =  13h 49m 07.5s
    Dec(J2000) = -10d 21' 11.0"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.

The burst came into the BAT field of view at ~T-60 seconds, following a pre-planned
slew and another slew took it out of the field at around T+215 seconds.
mask-weighted light curve shows a broad peak from T-30 s to T+70 s, with at least
six subpeaks superimposed. T90 (15-350 keV) is 97.3 +- 25.1 sec (estimated error
including systematics).

The time-averaged spectrum from T-20.15 to T+108.07 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.54 +- 0.73,
and Epeak of 71.7 +- 31.8 keV (chi squared 58.75 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T-6.49 sec in the 15-150 keV band is
0.5 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.52 +- 0.14 (chi squared 65.60 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/571271/BA/