[vsnet-grb-info 27128] GRB 210102C: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29231
SUBJECT: GRB 210102C: Swift-BAT refined analysis
DATE:    21/01/03 23:41:32 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien at nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+537 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 210102C (trigger #1015728)
(Troja et al., GCN Circ. 29226).  The BAT ground-calculated position is
RA, Dec = 235.747, -37.231 deg which is
   RA(J2000)  =  15h 42m 59.2s
   Dec(J2000) = -37d 13' 52.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 76%.

The mask-weighted light curve shows a double-peaked structure. The first
peak starts at ~T-2 s, peaks at ~T0, and ends at ~T+8 s. The second peak
starts at ~T+55 s, peaks at ~T+67 s, and ends at ~T+100 s. T90 (15-350 keV)
is 87.25 +- 4.97 sec (estimated error including systematics).

The time-averaged spectrum from T-2.07 to T+97.42 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.87 +- 0.08.  The fluence in the 15-150 keV band is
3.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from
T+66.72 sec in the 15-150 keV band is 4.4 +- 0.3 ph/cm2/sec.  All the
quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/1015728/bascript/top.html