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GCN Circular 33279

Subject

GRB 230204A: Swift-BAT refined analysis

Date

2023-02-06T03:46:38Z (a year ago)

From

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

T. Parsotan (GSFC/UMBC), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
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 230204A (trigger #1152509)
(D'Ai et al., GCN Circ. 33260Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 238.166, -50.848 deg which is
   RA(J2000)  =  15h 52m 39.8s
   Dec(J2000) = -50d 50' 52.8"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T-10 and ends at ~T+200 s. The most prominent peak
occurs at ~T+148 s. T90 (15-350 keV) is 182.05 +- 16.73 sec
(estimated error including systematics).

The time-averaged spectrum from T-6.81 to T+195.62 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.72 +- 0.13.  The fluence in the 15-150 keV band is 3.7 +- 0.3 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+148.12 sec in the 15-150 keV band
is 0.9 +- 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/1152509/BA/