GCN Circular 22038
Subject
GRB 171020A: Swift-BAT refined analysis
Date
2017-10-21T15:54:40Z (7 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), K. L. Page (U Leicester)
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-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171020A (trigger #780845)
(Page et al., GCN Circ. 22028). The BAT ground-calculated position is
RA, Dec = 39.260, 15.199 deg which is
RA(J2000) = 02h 37m 02.3s
Dec(J2000) = +15d 11' 57.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.
The mask-weighted light curve shows a weak pulse that starts at ~T0 and
ends at ~ T+45 s. T90 (15-350 keV) is 41.9 +- 9.2 sec (estimated error
including systematics).
The time-averaged spectrum from T-0.97 to T+46.68 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.04 +- 0.20. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+19.92 sec in the 15-150 keV band
is 0.7 +- 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/780845/BA/