GCN Circular 18944

S. D. Barthelmy (GSFC), A. Amaral-Rogers (U Leicester),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
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+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160127A (trigger #671828)
(Amaral-Rogers et al., GCN Circ. 18938
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 225.966, 0.080 deg which is
  RA(J2000)  =  15h 03m 51.8s
  Dec(J2000) = +00d 04' 46.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.

The mask-weighted light curve shows a double-peaked structure that starts
at ~ T-1 s and ends at ~ T+6 s. The two peaks occur at ~ T+1 and ~T+3 s,
respectively. T90 (15-350 keV) is 6.16 +- 0.94 sec (estimated error including
systematics).

The time-averaged spectrum from T-1.44 to T+5.70 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.99 +- 1.11,
and Epeak of 25.6 +- 0.0 keV (chi squared 44.15 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.5 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+3.34 sec in the 15-150 keV band is
1.4 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.43 +- 0.23 (chi squared 50.23 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/671828/BA/