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GCN Circular 31149

Subject

GRB 211129A: Swift-BAT refined analysis

Date

2021-11-30T03:22:44Z (3 years ago)

From

Amy Lien at GSFC <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. D. Gropp (PSU), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), 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+800 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 211129A (trigger #1085430)
(Gropp et al., GCN Circ. 31136Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 274.565, 31.781 deg which is
   RA(J2000)  =  18h 18m 15.6s
   Dec(J2000) = +31d 46' 51.5"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 83%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-2 s and ends at ~T+120 s. The three main peaks occur at ~T+1 s,
~T+29 s, and ~T+91 s, respectively. T90 (15-350 keV) is 113.01 +- 9.14 sec
(estimated error including systematics).

The time-averaged spectrum from T-1.80 to T+124.11 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.75 +- 0.13.  The fluence in the 15-150 keV band
is 2.3 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+0.99 sec in the 15-150 keV band is 1.5 +- 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/1085430/BA/