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GCN Circular 25482

Subject
GRB 190824A, Swift-BAT refined analysis
Date
2019-08-26T20:50:27Z (5 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
J. R. Cummings (CPI) S. D. Barthelmy (GSFC), V. D'Elia (SSDC),
H. A. Krimm (NSF), A. Y. Lien (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-230 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 190824A (trigger #922107)
(D'Elia, et al., GCN Circ. 25463Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 215.323, -41.900 deg which is 
  RA(J2000)  =  14h 21m 17.6s 
  Dec(J2000) = -41d 53' 59.5" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 28%.

The mask-weighted light curve shows three main peaks, each with underlying 
substructure.  The first peak is from ~T-80 sec to T-60 sec.  The second,
largest, peak is from ~T-10 sec to T+50 sec, and the third peak is from
~T+85 sec to T+110 sec.   T90 (15-350 keV) is 169.4 +- 5.9 sec (estimated 
error including systematics).

The time-averaged spectrum from T-71.9 to T+114.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.62 +- 0.08.  The fluence in the 15-150 keV band is 8.5 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.12 sec in the 15-150 keV band
is 5.0 +- 0.5 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/922107/BA/