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GCN Circular 27194

Subject

GRB 200224A: Swift-BAT refined analysis

Date

2020-02-25T06:53:49Z (5 years ago)

From

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

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC),
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+962 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 200224A (trigger #958141)
(Ukwatta et al., GCN Circ. 27173Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 248.743, 41.666 deg which is
   RA(J2000)  =  16h 34m 58.4s
   Dec(J2000) = +41d 39' 57.2"
with an uncertainty of 3.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a weak pulse from ~T0 to ~T+5 s,
followed
by some weaker emission that lasts till ~T+50 s. T90 (15-350 keV)
is 45.0 +- 9.2 sec (estimated error including systematics).

The time-averaged spectrum from T-0.79 to T+49.21 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.69 +- 0.51.  The fluence in the 15-150 keV band is 2.9 +- 0.9 x 10^-7
erg/cm2.
The 1-sec peak photon flux measured from T+2.21 sec in the 15-150 keV band
is 0.4 +- 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/958141/BA/