TITLE: GCN CIRCULAR NUMBER: 18929 SUBJECT: GRB 160123A: Swift-BAT refined analysis DATE: 16/01/23 18:39:27 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. Malesani (DARK/NBI), 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 downlinks, we report further analysis of BAT GRB 160123A (trigger #671447) (Malesani, et al., GCN Circ. 18926). The BAT ground-calculated position is RA, Dec = 150.277, -33.790 deg, which is RA(J2000) = 10h 01m 06.4s Dec(J2000) = -33d 47' 23.1" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 68%. The mask-weighted light curve shows one peak starting at ~T-15 sec, peaking at ~T+0.5 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 3.95 +- 0.62 sec (estimated error including systematics). The time-averaged spectrum from T-2.05 to T+3.00 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.51 +- 0.16. The fluence in the 15-150 keV band is 3.5 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.01 sec in the 15-150 keV band is 1.3 +- 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/671447/BA/