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GCN Circular 20565

Subject

GRB 170127A: Swift-BAT refined analysis

Date

2017-01-29T16:00:54Z (7 years ago)

From

Amy Lien at GSFC <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), 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 170127A (trigger #735326)
(Markwardt et al., GCN Circ. 20538Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 174.382, -45.827 deg which is
   RA(J2000)  =  11h 37m 31.6s
   Dec(J2000) = -45d 49' 38.6"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 97%.

The mask-weighted light curve shows some weak overlapping pulses that
starts at ~T-5 s and ends at ~T+65 s. T90 (15-350 keV) is
62.26 +- 10.39 sec (estimated error including systematics).

The time-averaged spectrum from T-4.65 to T+64.51 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.10 +- 0.30.  The fluence in the 15-150 keV band is 5.2 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+7.31 sec in the 15-150 keV band
is 0.3 +- 0.2 ph/cm2/sec.  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/735326/BA/