D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
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), M. A. Williams (PSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry
we report further analysis of BAT GRB 230123A (trigger #1150429)
(Williams et al., GCN Circ. 33206). The BAT ground-calculated position is
RA, Dec = 40.905, -65.661 deg which is
RA(J2000) = 02h 43m 37.3s
Dec(J2000) = -65d 39' 39.9"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 88%.
The mask-weighted light curve shows a single-peaked structure
that starts at ~T-2 s, peaks at ~T+1, and ends at ~T+6 s.
T90 (15-350 keV) is 5.37 +- 1.03 sec (estimated error including
The time-averaged spectrum from T-1.25 to T+4.75 sec is best fit
by a simple power-law model. The power law index of the time-averaged
spectrum is 2.06 +- 0.24. The fluence in the 15-150 keV band
is 2.7 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T+0.12 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at