GCN Circular 28276
Subject
GRB 200819A: Swift-BAT refined analysis
Date
2020-08-21T02:37:04Z (4 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), S. Dichiara (NASA/GSFC/UMCP),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), 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-60 to T+243 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 200819A (trigger #992099)
(Dichiara et al., GCN Circ. 28263). The BAT ground-calculated position is
RA, Dec = 21.527, 63.061 deg which is
RA(J2000) = 01h 26m 06.4s
Dec(J2000) = +63d 03' 39.3"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
The mask-weighted light curve shows a double-peaked structure that starts
at ~T0 and ends at ~T+7 s, followed by some tail emission that
lasts until ~T+27 s. T90 (15-350 keV) is 23.62 +- 6.74 sec (estimated
error including systematics).
The time-averaged spectrum from T-0.72 to T+27.12 sec is best fit by a
simple power-law model. The power law index of the time-averaged
spectrum is 2.08 +- 0.31. The fluence in the 15-150 keV band is
3.2 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T+0.31 sec in the 15-150 keV band is 0.6 +- 0.1 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/992099/BA/