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GCN Circular 32361

Subject

GRB 220708A: Swift-BAT refined analysis

Date

2022-07-10T21:10:28Z (2 years ago)

From

Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>

S. D. Barthelmy (GSFC), D'Elia (SSDC & INAF-OAR),
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), T. Sakamoto (AGU), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
  
Using the data set from T-239 to T+1566 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220708A (trigger #1115156)
(D'Elia, et al., GCN Circ. 32343Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 103.038, 72.199 deg which is
    RA(J2000)  =  06h 52m 09.1s
    Dec(J2000) = +72d 11' 57.4"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.
  
The BAT mask-weighted light curve shows a peak starting from T-1 s to T+3 s.
T90 (15-350 keV) is 4.4 +- 1.0 sec (estimated error including systematics).
  
The time-averaged spectrum from T-1.55 to T+3.44 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.31 +- 0.32.  The fluence in the 15-150 keV band is 1.3 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.54 sec in the 15-150 keV band
is 0.8 +- 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/1115156/BA/