[vsnet-grb-info 24571] GRB 200107B: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26670
SUBJECT: GRB 200107B: Swift-BAT refined analysis
DATE:    20/01/08 16:50:49 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha at nasa.gov>

S. D. Barthelmy(GSFC), M.G. Bernardini(INAF-OAB), 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-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200107B (trigger #948219)
(M. G. Bernardini et al., GCN Circ. 26661).  The BAT ground-calculated position is
RA, Dec = 107.067, -83.716 deg which is
   RA(J2000)  =  07h 08m 16.0s
   Dec(J2000) = -83d 42' 56.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.


The mask weighted light curve shows complex multi-peak structures with a duration of ~100 s.
The overall structure starts at ~T-40 s and lasts till ~T+80s.
T90 (15-350 keV) is 86.68 +- 11.64 sec (estimated error including systematics).

The time-averaged spectrum from T-29.86 to T+77.04 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.41 +- 0.10.  The fluence in the 15-150 keV band is 3.0 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+36.09 sec in the 15-150 keV band
is 1.9 +- 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/948219/BA/