TITLE:   GCN CIRCULAR
NUMBER:  26861
SUBJECT: GRB 200122A: Swift-BAT refined analysis
DATE:    20/01/23 02:01:53 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
E. Sonbas (Adiyaman Univ.), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+302 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 200122A (trigger #950330)
(Sonbas et al., GCN Circ. 26844).  The BAT ground-calculated position is
RA, Dec = 210.010, 27.548 deg which is
   RA(J2000)  =  14h 00m 02.4s
   Dec(J2000) = +27d 32' 52.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.

The mask-weighted light curve shows a multi-peaked structure that starts
from ~T-10 s and ends at ~T+200 s. The main emission interval is
around T-10 s to T+50 s, with the highest peak occurs at ~T+10 s.
In addition, there is a weak pulse around ~T+192 s.
T90 (15-350 keV) is 174.96 +- 14.54 sec (estimated error including
systematics).

The time-averaged spectrum from T-8.572 to T+201.832 sec is best
fit by a simple power-law model.  The power law index of the
time-averaged spectrum is 1.60 +- 0.05.  The fluence in the 15-150 keV
band is 1.1 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured
from T+10.18 sec in the 15-150 keV band is 9.1 +- 0.4 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/950330/BA/