[vsnet-grb-info 17456] GRB 160117A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18882
SUBJECT: GRB 160117A: Swift-BAT refined analysis
DATE:    16/01/17 23:00:29 GMT
FROM:    Craig Markwardt at NASA/GSFC  <craigm at milkyway.gsfc.nasa.gov>

D. M. Palmer, S. D. Barthelmy (GSFC), 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-173 to T+1029 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160117A (trigger #670793)
(Markwardt, et al., GCN Circ. 18874).  The BAT ground-calculated position is
RA, Dec = 20.367, -0.677 deg which is
    RA(J2000)  =  01h 21m 28.0s
    Dec(J2000) = -00d 40' 37.8"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve consists of a faint precursor from about
T-70 sec to T+30 sec, followed by brighter double-peaked structure from
about T+30 sec to T+115 sec. T90 (15-350 keV) is 118.58 +- 20.46 sec
(estimated error including systematics).

The time-averaged spectrum from T-46 to T+109 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.14 +- 0.11.  The fluence in the 15-150 keV band is 3.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+76 sec in the 15-150 keV band
is 1.4 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Please note that GRB 160117B was incorrectly marked with the same trigger
number as GRB 160117A in Sonbas et al. 2016 (GCN Circ. 18875).  The correct
trigger number for 160117A is above.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/670793/BA/