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GCN Circular 27793

Subject

GRB 200522A: Swift-BAT refined analysis

Date

2020-05-23T21:14:23Z (4 years ago)

From

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

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. A. Evans (U Leicester),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU) (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 200522A (trigger #973628)
(Evans et al., GCN Circ. 27778Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 5.668, -0.264 deg which is
   RA(J2000)  =  00h 22m 40.3s
   Dec(J2000) = -00d 15' 49.9"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T-0.3 s and ends at ~T+0.7 s. The main peak occur at ~T0. T90 (15-350
keV)
is 0.62 +- 0.08 sec (estimated error including systematics).

The time-averaged spectrum from T-0.02 to T+0.67 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.45 +- 0.17.  The fluence in the 15-150 keV band is
1.1 +- 0.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T-0.17 sec in the 15-150 keV band is 1.5 +- 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/973628/BA/