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GCN Circular 20557

Subject

GRB 170126A, Swift-BAT refined analysis

Date

2017-01-28T05:03:02Z (8 years ago)

From

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

T. Sakamoto (AGU), 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),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+200 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170126A (trigger #735188)
(Kocevski, et al., GCN Circ. 20530Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 263.623, -64.755 deg which is
   RA(J2000)  =  17h 34m 29.4s
   Dec(J2000) = -64d 45' 18.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 4%.

The mask-weighted light curve shows a single-peaked structure that starts
at ~T-1 s, peaks at ~T+1 s, and ends at ~T+11 s. T90 (15-350 keV) is
9.5 +- 1.6 sec (estimated error including systematics).

The time-averaged spectrum from T-0.8 to T+10.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.54 +- 0.14.  The fluence in the 15-150 keV band is 2.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.31 sec in the 15-150 keV band
is 7.3 +- 1.1 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/735188/BA/