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GCN Circular 34082

Subject
GRB 230622A: Swift-BAT refined analysis
Date
2023-06-26T16:15:20Z (a year ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
D. M. Palmer (LANL), C. B. Markwardt (GSFC),
S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
 S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),,
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
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 report further analysis of BAT GRB 230622A (trigger #1176135)
(Melandri, et al., GCN Circ. 34058).  The BAT ground-calculated position is
RA, Dec = 292.516, -32.972 deg which is
   RA(J2000)  =  19h 30m 03.8s
   Dec(J2000) = -32d 58' 20.6"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.

The BAT  light curve shows a complex structure with a duration of ~ 20 sec.
The second soft peak at T~24 sec is probably due to calibration and/or instrument effects, and possibly not related to the GRB.
T90 (15-350 keV) is 18.37 +- 13.63 sec (estimated error including systematics).

The time-averaged spectrum from T-0.06 to T+23.88 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.52 +- 0.43.  The fluence in the 15-150 keV band is 4.1 +- 1.0 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.05 sec in the 15-150 keV band
is 2.8 +- 0.4 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/1176135/BA/

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