[vsnet-grb-info 28522] GRB 210807C: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30625
SUBJECT: GRB 210807C: Swift-BAT refined analysis
DATE:    21/08/10 21:58:19 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha at nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 210807C (trigger #1064421)
(Lien et al., GCN Circ. 30610).  The BAT ground-calculated position is
RA, Dec = 143.540, -51.409 deg which is
   RA(J2000)  =  09h 34m 09.7s
   Dec(J2000) = -51d 24' 32.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 20%.

The BAT light curve showed a complex structure with a duration of about ~100 sec.
T90 (15-350 keV) is 89.97 +- 6.26 sec (estimated error including systematics).

The time-averaged spectrum from T-31.36 to T+78.57 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.65 +- 0.06.  The fluence in the 15-150 keV band is 1.2 +- 0.0 x 10^-05 erg/cm2.
The 1-sec peak photon flux measured from T-24.22 sec in the 15-150 keV band
is 4.0 +- 0.7 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/1064421/BA/