GCN Circular 33694
Subject
GRB 230423A(trigger #1165354): Swift-BAT refined analysis
Date
2023-04-27T21:21:35Z (a year ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
M. Stamatikos (OSU)(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we have found that BAT trigger #1165354 is a GRB 230423A even though
the original GCN Circular (Brivio et al., GCN Circ. 33677) based on the immediately
available data suggested that it was probably a statistical fluctuation.
The BAT ground-calculated position is
RA, Dec = 122.618, -21.901 deg which is
RA(J2000) = 08h 10m 28.2s
Dec(J2000) = -21d 54' 03.6"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The BAT light curve showed a complex structure with a duration of about 30 sec.
T90 (15-350 keV) is 23.60 +- 4.27 sec (estimated error including systematics).
The time-averaged spectrum from T-2.25 to T+24.49 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.69 +- 0.27. The fluence in the 15-150 keV band is 4.6 +- 0.8 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+10.62 sec in the 15-150 keV band
is 0.6 +- 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/1165354/BA/